Plastic Pollution: Causes, Sources, Effects & Solutions

Plastic Pollution: Causes, Sources, Effects & Solutions

Waste pollution is a big issue in the world.

One of the most destructive waste materials is plastic, and plastic pollution can have significant impacts on humans, animals and the natural environment.

In this guide we discuss what plastic pollution is, the causes, the sources of plastic production, the effects, and potential solutions to mitigate and reduce plastic pollution.

(NOTE: we have heavily paraphrased in this guide. You can find their full articles here –, and here

You can also read more generally about waste pollution in this guide


Summary – Plastic Pollution

  • Plastic is often cheap, durable, takes a long time to break down, and can be used for a range of uses in society – making it a popular material that delivers both pros and cons
  • Plastic comes in many different types, forms and sizes
  • Single use plastic can be delineated from plastics that last multiple years or even decades (such as plastics used in construction)
  • Microplastics happen with the break down of bigger plastic items and material
  • In developed countries, plastic may be disposed of via landfills, incineration and recycling. Plastic is generally well contained and handled in countries with good waste management systems (landfills tend to be well managed and contained compared to poorer countries)
  • In developing countries, or countries with poor waste management systems – plastic is often littered, disposed of in unconfined landfills (where it blows or washes away), and can end up in rivers … where it gets carried out to sea
  • Most of the plastic found in the ocean comes from Asia – carried from rivers in China and India for example
  • Countries around the middle of the global income spectrum tend to have the highest per capita mismanaged plastic rates
  • High income countries produce far more plastic per person than low and middle income countries in general – but, once you correct figures for amount of mismanaged plastic waste, they have less impact on plastic pollution that ends up in the environment
  • Industries that produce the most primary plastics are packaging, with 42 percent of plastics entering the use phase. Building and construction was the second largest sector utilizing 19 percent of the total. But, plastic packaging tends to be far more of the single use kind
  • In terms of household waste, EPA figures show plastic trails paper, food and yard trimmings waste. Plastic accounts for around 13% of municipal waste
  • An often overlooked cause of plastic waste is fishing equipment and fishing gear from things such as ghost fishing and commercial fishing waste. Nets and fishing lines are common fishing waste found in the ocean
  • Reducing plastic waste, and mismanaged plastic waste, will involve a collaborative approach between individuals, the government and private business 
  • Aside from reducing plastic waste, we need to find better ways to re-use, recycle and dispose of plastic
  • With effective waste management systems across the world, mismanaged plastics at risk of entering the ocean could decline by more than 80 percent. If we focus all of our energy on contributions of negligible size [like plastic straws which are only 0.03% of total plastic waste in the ocean], we risk diverting our focus away from the large-scale contributions we need.
  • In terms of mismanaged waste (littering and inadequately disposed of), a high share of the world’s ocean plastics pollution has its origin in Asia. China contributes the highest share of mismanaged plastic waste with around 28 percent of the global total, followed by 10 percent in Indonesia, 6 percent for both the Philippines and Vietnam.
  • Other leading countries include Thailand (3.2 percent); Egypt (3 percent); Nigeria (2.7 percent) and South Africa (2 percent).


What Is Plastic Pollution?

Plastic entering the environment and harming humans, animals, living organisms, and the natural environment.

Once plastic is discarded, it can either be adequately disposed of via properly managed landfills, incinerators or recycling.

It can also be mismanaged via littering or inadequately managed disposal sites.


Types Of Plastic

  • Polymers, synthetic fibers and additives
  • Primary plastics and other plastics
  • Nano plastics, small micro plastics, large micro plastics, meso plastics, macro plastics



  • Plastics that act as pollutants are categorized into micro-, meso-, or macro debris, based on size.

– Wikipedia


Stages Of The Plastic Pollution Cycle, & How Plastic Pollution Generally Happens

From 2014 and 2015 estimates:

  • Production – plastic is made (270 million tonnes)
  • Global plastic waste – amount of plastic disposed of (275 million tonnes – can be more than production numbers in any given year because plastic from previous years becomes waste)
  • Coastal plastic waste – total of plastic generated by populations within 50km of a coastline, which is at most risk of entering the ocean (99.5 million tonnes)
  • Mismanaged coastal plastic waste – sum of inadequately managed and littered waste from coastal populations. Inadequately managed waste is stored in open or insecure landfills. (31.9 million tonnes)
  • Plastic inputs to the ocean – micro and macro plastic waste input into the ocean (8 million tonnes)
  • Estimated plastic in surface water – 10,000 to 100,000 tonnes. Can end up in animals and on ocean floor



How Is Plastic Generally Disposed Of?

Of the plastic produced, some of it stays in use for various applications, but the plastic that that doesn’t stay in use (like single use plastics for example), needs to be disposed of.

This is done mainly via landfills, incineration and recycling.

In 2015, an estimated 55 percent of global plastic waste was discarded, 25 percent was incinerated, and 20 percent recycled.

If we extrapolate historical trends through to 2050 —  by 2050, incineration rates would increase to 50 percent; recycling to 44 percent; and discarded waste would fall to 6 percent. However, note that this is based on the simplistic extrapolation of historic trends and does not represent concrete projections.



When Did Plastic Pollution Start Becoming A Problem?

  • Rapid growth in global plastic production started in the 1950’s
  • From 1950 to 2015, annual production of plastics increased nearly 200-fold to 381 million tonnes in 2015



Biggest Reasons For Plastic Pollution

  • Plastic is inexpensive, easy and cheap to make
  • Plastic is durable as a material
  • Plastic has a lot of benefits (such as preventing food waste, and packaging)
  • The chemical structure of most plastics renders them resistant to many natural processes of degradation and as a result they are slow to degrade – they stick in the natural environment around and cause damage in the environment
  • Macro plastics break down – but break down into micro plastics



Causes, & Sources Of Plastic Pollution

Land Based vs Marine Based Plastics

  • Approximately 70-80 percent of ocean plastics come from land-based sources, and 20-30 percent from marine.
  • Whilst this is the relative contribution as an aggregate of global ocean plastics, the relative contribution of different sources will vary depending on geographical location and context.
  • In particular regions, marine sources can dominate.
  • For example, more than half of plastics in the Great Pacific Garbage Patch (GPGP) come from fishing nets, ropes and lines. It’s estimated that plastic lines, ropes and fishing nets comprise 52 percent of the plastic mass in the ‘Great Pacific Garbage Patch’ (GPGP) (and comprises 46 percent of the megaplastics component of the GPGP). The relative contribution of marine sources here is likely to be the result of intensified fishing activity in the Pacific Ocean.

Industries & Sectors That Use Plastic The Most

  • Packaging was the dominant use of primary plastics, with 42 percent of plastics entering the use phase. Building and construction was the second largest sector utilizing 19 percent of the total.
  • Primary plastic production does not directly reflect plastic waste generation, since this is also influenced by the polymer type and lifetime of the end product.
  • Packaging, for example, has a very short ‘in-use’ lifetime (typically around 6 months or less). This is in contrast to building and construction, where plastic use has a mean lifetime of 35 years. Packaging is therefore the dominant generator of plastic waste, responsible for almost half of the global total.
  • Since packaging tends to have a much lower product lifetime than other products (such as construction or textiles), it is also dominant in terms of annual waste generation. It is responsible for almost half of global plastic waste
  • In 2015, primary plastics production was 407 million tonnes; around three-quarters (302 million tonnes) ended up as waste.
  • Are straws a big deal? Not really. It’s estimated that if all straws around the world’s coastlines were lost to the ocean, this would account for approximately 0.03 percent of ocean plastics. A global ban on their use could therefore achieve a maximum of a 0.03 percent reduction. Why have straws in particular received so much attention? Probably because: (a) for most people (not all — some people struggle to drink without one), straws are unnecessary; and (b) it’s a quick and low-risk step for businesses to be seen to be taking active steps in addressing this issue.
  • As some have highlighted: other sources of plastic pollution — such as discards of fishing nets and lines (which contributed to more than half of plastics in the Great Pacific Garbage Patch) receive significantly less attention. With effective waste management systems across the world, mismanaged plastics at risk of entering the ocean could decline by more than 80 percent. If we focus all of our energy on contributions of negligible size, we risk diverting our focus away from the large-scale contributions we need.



Countries That Contribute To Plastic Waste & Pollution

  • High-income countries tend to generate more plastic waste per person
  • How plastic waste is managed determines its risk of entering the ocean. High-income countries have very effective waste management systems; so, mismanaged waste (and ocean inputs) are therefore low. Poor waste management across many middle- and low-income countries means they dominate the sources of global ocean plastic pollution
  • Daily per capita plastic waste across the highest countries – Kuwait, Guyana, Germany, Netherlands, Ireland, the United States – is more than ten times higher than across many countries such as India, Tanzania, Mozambique and Bangladesh. Note that these figures represent total plastic waste generation and do not account for differences in waste management, recycling or incineration. They therefore do not represent quantities of plastic at risk of loss to the ocean or other waterways.
  • Mismanaged, inadequately disposed and littered plastic is a problem, compared to say contained and managed plastic in landfills or incinerated plastic
  • In terms of mismanaged waste (littering and inadequately disposed of), a high share of the world’s ocean plastics pollution has its origin in Asia. China contributes the highest share of mismanaged plastic waste with around 28 percent of the global total, followed by 10 percent in Indonesia, 6 percent for both the Philippines and Vietnam.
  • Other leading countries include Thailand (3.2 percent); Egypt (3 percent); Nigeria (2.7 percent) and South Africa (2 percent).
  • Whilst many countries across Europe and North America had high rates of per capita plastic generation, once corrected for waste management, their contribution to mismanaged waste at risk of ocean pollution is significantly lower.
  • The East Asia and Pacific region dominates global mismanaged plastic waste, accounting for 60 percent of the world total.
  • Plastic enters the ocean from many different sources, and rivers contribute greatly. The Yangtze, Ganges and Xi are the main offenders, with China and India being home to most of the plastic polluted rivers
  • Asia contributed to 86% of river plastic pollution in 2015



Plastic In The Ocean

  • It’s estimated that around three percent of global annual plastic waste enters the oceans each year. In 2010, this was approximately 8 million tonnes.
  • Plastic enters the oceans from coastlines, rivers, tides, and marine sources
  • Most of the plastic that enters the ocean is from coastline populations that are located 50km or less from the ocean itself
  • The distribution and accumulation of ocean plastics is strongly influenced by oceanic surface currents and wind patterns.
  • Eriksen et al. (2014) estimated that there was approximately 269,000 tonnes of plastic in ocean surface waters across the world.
  • It’s estimated that there are more than 5 trillion plastic particles in the world’s ocean surface waters
  • The majority of plastics by mass are large particles (macroplastics), whereas the majority in terms of particle count are microplastics (small particles).
  • Great Pacific Garbage Patch – the estimated composition of the GPGP plastic…. Around 52 percent of plastics originated from fishing activity and included fishing lines, nets and ropes; a further 47 percent was sourced from hard plastics, sheets and films; and the remaining components were small in comparison (just under one percent). The dominance of fishing lines, nets, hard plastics and films means that most of the mass in the GPGP had a large particle size (meso- and macroplastics).
  • To understand where plastic entering the oceans is coming from, we are primarily concerned with mismanaged waste in coastal populations. Mismanaged waste is plastics which are disposed of in open landfills or dumps, littered, or otherwise discarded by means which can spill out to the surrounding environment.
  • River inputs are a significant source of plastic inputs to the ocean.



The Missing Plastics Problem In The Ocean

  • When you look at the amount of plastic that enters oceans and the amount of plastic that floats on ocean surfaces, the amounts don’t add up
  • This is known as the missing plastics problem i.e. figuring out where the plastic is going once it enters the ocean
  • It’s unknown where the majority of ocean plastics end up as plastic is hard to track once it enters the ocean. There are multiple hypotheses as to where missing plastic accumulates.
  • It’s important to note that within the marine environment, plastics can more readily break down into smaller particles: exposure to ultraviolet (UV) radiation, and consistent mechanical abrasion from wave action can cause larger particles to break down. This allows for easier incorporation into sediments and ingestion by organisms.
  • A likely ‘sink’ for ocean plastics are deep-see sediments; a study which sampled deep-sea sediments across several basins found that microplastics, in the form of fibres, was up to four orders of magnitude more abundant (per unit volume) in deep-sea sediments from the Atlantic Ocean, Mediterranean Sea and Indian Ocean than in plastic-polluted surface waters.
  • The other possible ‘sinks’ of missing plastics are shallow-sea sediments, in addition to potential ingestion by organisms.
  • The quantification of these aspects are as yet unknown.



Effects & Impact Of Plastic Pollution

  • Plastic has a large negative impact on wildlife and oceans
  • For wild animals, entanglement with plastic and ingestion of plastic are big issues
  • Abrasion with plastic is also an issue – for example fishing gear damaging coral
  • With micro plastics, the key concern is ingestion for animals. This can occur through several mechanisms, ranging from uptake by filter-feeders, swallowing from surrounding water, or consumption of organisms that have previously ingested microplastics.
  • Ingestion of plastic can occur unintentionally, intentionally, or indirectly through the ingestion of prey species containing plastic and it has now been documented for at least 233 marine species, including all marine turtle species, more than one-third of seal species, 59% of whale species, and 59% of seabirds. Ingestion by 92 species of fish and 6 species of invertebrates has also been recorded.
  • Microplastic ingestion rarely causes mortality/death in any organisms
  • There is increasing evidence that microplastic ingestion can affect the consumption of prey, leading to energy depletion, inhibited growth and fertility impacts. When organisms ingest microplastics, it can take up space in the gut and digestive system, leading to reductions in feeding signals. This feeling of fullness can reduce dietary intake.
  • Many organisms do not exhibit changes in feeding after microplastic ingestion. A number of organisms, including suspension-feeders (for example, oyster larvae, urchin larvae, European flat oysters, Pacific oysters) and detritivorous (for example, isopods, amphipods) invertebrates show no impact of microplastics.
  • Overall, however, it’s likely that for some organisms, the presence of microplastic particles in the gut (where food should be) can have negative biological impacts.
  • Entanglement cases have been reported for at least 344 species to date, including all marine turtle species, more than two-thirds of seal species, one-third of whale species, and one-quarter of seabirds. Entanglement by 89 species of fish and 92 species of invertebrates has also been recorded.
  • Entanglements most commonly involve plastic rope and netting and abandoned fishing gear. However, entanglement by other plastics such as packaging have also been recorded.
  • There is, currently, very little evidence of the impact of microplastics in humans. Despite having no clear evidence of health impacts, research on potential exposure is ongoing.
  • For human health, it is the smallest particles — micro- and nano-particles which are of greatest concern. Particles must be small enough to be ingested.
  • There are several ways by which plastic particles can be ingested: orally through water, consumption of marine products which contain microplastics, through the skin via cosmetics (identified as highly unlikely but possible), or inhalation of particles in the air.
  • One factor which possibly limits the dietary uptake for humans is that microplastics in fish tend to be present in the gut and digestive tract — parts of the fish not typically eaten. The presence of microplastics in fish beyond the gastrointestinal tract (e.g. in tissue) remains to be studied in detail. Micro- and nanoplastics in bivalves (mussels and oysters) cultured for human consumption have also been identified.
  • However, any human exposure and potential risk is not yet able to be identified or quantified.
  • Plastic fibres have also been detected in other food items; for example, honey, beer and table salt. However, it’s expected there is negligible health risks as a result of this exposure.
  • Levels of microplastic ingestion are currently unknown. Even less is known about how such particles interact in the body. It may be the case that microplastics simply pass straight through the gastrointestinal tract without impact or interaction.
  • What could cause concern about the impact of microplastics?
  • Three possible toxic effects of plastic particle have been suggested: plastic particles themselves, the release of persistent organic pollutant adsorbed to the plastics, and leaching of plastic additives. There has been no evidence of harmful effects to date (however, the precautionary principle would indicate that this is not evidence against taking exposure seriously).
  • To date, there has been no clear evidence of the accumulation of persistent organic pollutants or leached plastic additives in humans. Continued research in this area, however, is important to better understand the role of plastic within broader ecosystems and risk to human health.



You can also read about more negative effects of plastic pollution in the disposal sections below – landfill, incineration and recycling.


Trends And Stats On Plastic Production

  • From 1950 to 2015, annual production of plastics increased nearly 200-fold to 381 million tonnes in 2015
  • In 1950 the world produced only 2 million tonnes per year
  • In 2010 – global primary production of plastic was 270 million tonnes
  • In 2010 – global plastic waste was 275 million tonnes (and can exceed annual primary production through wastage of plastic from prior years)
  • In 2010 – plastic waste most at risk of entering the oceans is generated in coastal populations (within 50 kilometres of the coastline); coastal plastic waste amounted to 99.5 million tonnes in 2010
  • In 2010 – only plastic waste which is improperly managed (mismanaged) is at significant risk of leakage to the environment; in 2010 this amounted to 31.9 million tonnes. Of this, 8 million tonnes – 3% of global annual plastics waste – entered the ocean (through multiple outlets, including rivers)
  • In 2010 – an estimated 10,000s to 100,000s tonnes of plastics are in the ocean surface waters (several orders of magnitude lower than ocean plastic inputs). This discrepancy is known as the ‘missing plastic problem’ and is discussed here in this guide
  • Cumulatively – by 2015, the world had produced 7.8 billion tonnes of plastic — more than one tonne of plastic for every person alive today.
  • In 2015, an estimated 55 percent of global plastic waste was discarded, 25 percent was incinerated, and 20 percent recycled.
  • Between 1950 to 2015 – cumulative production of polymers, synthetic fibers and additives was 8300 million tonnes. Very little has been re-used or recycled
  • Plastic waste generation tends to increase as we get richer. Per capita plastic waste at low incomes tends to be notably smaller.
  • Mismanaged waste generation tends to be low at very low incomes (since per capita waste is small); it then rises towards middle incomes; and then falls again at higher incomes. Countries around the middle of the global income spectrum therefore tend to have the highest per capita mismanaged plastic rates.
  • This has typically occurred where countries have rapidly industrialised (allowing for significant economic growth towards the middle of the income spectrum), but at a rate far exceeding progress in waste management. Waste management infrastructure has failed to keep pace with industrial and manufacturing growth, leading to higher rates of mismanaged waste.
  • It is also the case that countries with high levels of mismanaged waste also have large coastal populations (as shown in the second chart below). This exacerbates the challenge of ocean plastic pollution because poorly-managed waste is at high risk of entering the ocean.
  • Overall, it’s generally the case that plastic waste per person is highest in high-income countries. However, richer countries tend to have effective waste management systems meaning mismanaged waste is low. Most mismanaged waste tends to arise from low-to-middle income countries where large coastal populations and rapid industrialization means waste management systems have failed to keep pace.
  • Oil used to make plastic – Estimates vary by source, but tend to converge on a range between 4 to 8 percent of global oil consumption. 6 percent of global oil consumption is taken as the mid-range estimate.



Forecasts For Mismanaged Plastic (Inadequately Disposed, & Littered Plastic)

  • Overall we see that the global distribution is projected to change only slightly; whilst China’s contribution falls by a couple of percentage points, East Asia & Pacific maintain around 60 percent of the total. South Asia’s contribution — largely driven by India — increases slightly, as does Sub-Saharan Africa. Latin America, the Middle East & North Africa, Europe and North America all fall in relative terms.



Solutions For Plastic Pollution

  • Plastic substitutes and alternatives – it’s also important to note that plastic is a unique material with many benefits: it’s cheap, versatile, lightweight, and resistant. This makes it a valuable material for many functions. It can also provide environmental benefits through certain supply chains: it plays a critical role in maintaining food quality, safety and preventing waste. The trade-offs between plastics and substitutes (or complete bans are therefore complex and could create negative knock-on environmental impacts
  • Fix high and low income country waste management systems so there is less waste that escapes
  • The development of effective waste management infrastructure, particularly in middle-income (and growing lower-income) countries will be crucial to tackling the issue of mismanaged plastic pollution.
  • As some have highlighted: other sources of plastic pollution — such as discards of fishing nets and lines (which contributed to more than half of plastics in the Great Pacific Garbage Patch) receive significantly less attention. With effective waste management systems across the world, mismanaged plastics at risk of entering the ocean could decline by more than 80 percent. If we focus all of our energy on contributions of negligible size, we risk diverting our focus away from the large-scale contributions we need.



According to, further things we can do to stop plastic entering the ocean as individuals, innovators, corporations, and in policy-making and financing are…


  • Cut out non-essential plastics where possible, as long as we are not taking away from benefits the plastic might be providing
  • If you can replace single-use plastics with long-term, sustainable alternatives then substitute. To make this worthwhile across other environmental metrics (e.g. energy use, water use, greenhouse gas emissions), you often need to use them many times over a significant period of time. If you continually purchase alternatives to single-use plastic bags, for example, you’re probably increasing your environmental impact in other ways.
  • In most cases, recycling plastic is better than incineration or landfill. Therefore recycle whenever possible.
  • Note though that most plastics are recycled only once or a few times before also ending up in landfill or incineration. The notion that recycled plastic has no impact (and can therefore be used indefinitely) is a misconception.
  • Look at your local recycling guidelines to make sure you know what can and can’t be recycled in your area. Avoid putting plastics in recycling which cannot be handled properly. If in doubt, you’re better to put it in landfill than risk contaminating the whole recycling load (if recycling loads have significant levels of contamination they be judged to be non-economic to sort and therefore sent straight to landfill).
  • In high-income countries (typically with good waste management systems), plastics at risk of entering the ocean arise from littering and dumping of waste by the public.
  • Don’t litter or abandon your waste, and call out anyone who does. Through collective action, zero tolerance can become a societal norm.
  • As individuals we can be limited in the magnitude of our impact. The above changes can make a contribution, but as the late David MacKay noted: “If we all do a little, we’ll only achieve a little”.
  • Even if all countries across Europe and North America cut out plastic use completely, global mismanaged plastic would decline by less than five percent. To drive urgent and large-scale change, arguably our most important role lies in putting pressure on governments and policy-makers to collaborate globally.

Governments and policy-makers:

  • It has been a historic trend that some high-income countries have exported some of their recyclable plastics elsewhere. This has often been to mid- and low-income countries where poor waste management infrastructure has led to high levels of mismanaged waste. This exported waste is therefore at risk of entering the ocean.
  • High-income countries should manage all of their waste appropriately and avoid such transfers to countries which higher risk of poor management.
  • Some have proposed that if trade of recycled plastics was maintained, mid- or low-income countries should tax the plastics they accept. These taxes should be used to expand and improve waste management infrastructure.
  • An estimated 20 percent of ocean plastic pollution results from the fishing industry. However, in particular regions — for example, the Great Pacific Garbage Patch — fishing activity is estimated to generate more than half of plastic pollution. Implementing and monitoring of strict regulations on the prevention of waste from fishing activity is important not only at national levels but through regional and global cooperation.
  • The majority of plastic enters the ocean as a result of inadequate waste management; open landfills and dumps can’t effectively prevent plastics from being lost to the environment. Improving waste management infrastructure – particularly across industrializing countries – is critical and urgent if we are to prevent and reduce plastics entering the ocean.
  • As a general sense of magnitude: if all countries had the management infrastructure of high-income countries (i.e. no mismanaged waste with the exception of littering), global plastics at risk of entering the ocean could decline by more than 80 percent.
  • Global cooperation to upscale waste management is therefore crucial. Such solutions are not new or innovative: they have already been implemented successfully across many countries. Note that this is not a case of finger-pointing or blame: rich countries too have benefited from the rapid industrialization (a rate at which waste management could not keep up) of others. This is a global system we have collective responsibility for.
  • Middle- and low-income countries where plastics are poorly managed have an obvious role and responsibility. But if high-income countries are truly serious about addressing the ocean plastic issue, the most impactful way to contribute is to invest in the improvement of waste management infrastructure practices across the world. Without such investment and cooperation we will not be able to reduce the quantity of plastic entering the ocean.
  • We are still currently on a trend of rapidly increasing plastic waste: to stabilise, let alone reduce, will require large-impact solutions.

Innovation and industry:

  • Effective management of waste we produce is an essential and urgent demand if we are to prevent plastic entering the ocean. This is a solution we know how to achieve: many countries have low levels of mismanaged waste. This is important, regardless of how successful we are in reducing plastic usage.
  • However, reducing demand for new plastic production is also crucially important. Whilst recycled plastic is usually favourable to primary plastics, it is not a long-term solution: most recycled plastics still end up in landfill or incineration after one or two cycles.
  • For recycling to be sustainable over the long-term, innovations which would allow for continuous recycling would have to be developed. There has been promising progress in recent years in the development of polymer materials which can be chemically recycled back to their initial raw materials. However, they are currently expensive and unfavourable in terms of energy inputs.
  • The economic viability and environmental trade-offs will be critical components to the development of not only recyclable materials but other alternatives. Plastic is so widely used because it is cheap, versatile, and requires relatively little energy, water and land to produce.
  • To achieve wide uptake of alternatives across countries of all income levels, breakthrough alternatives will have to be economically competitive with current methods. Functionality, price and scalability of innovations are key to addressing this challenge.


According to, this information on removing plastics already in the ocean:

  • Plastic removal at large-scale is always going to be a major challenge.
  • This becomes an even greater challenge over time, since plastics in the ocean tend to break down into smaller particles (and the smaller they are, they less easy it is to detect and them remove them at scale).
  • Of course the easiest way to mitigate this problem is to stop plastic entering the ocean in the first place.
  • But still, we already have a large quantity of plastic in the ocean and this will continue (even if we can begin to reduce the amount that reaches the ocean in the years which follow).
  • Very small particles (microplastics, for example) are difficult to remove.
  • Technologies being proposed currently for plastic removal therefore tend to focus on larger plastics.
  • The fact that plastic tends to accumulate in gyres at the centre of ocean basins makes this easier: it concentrates plastics for removal.
  • The removal solution which has received the most attention from investors and researchers is The Ocean Cleanup. They are focusing on one major gyre of plastic: the Great Pacific Garbage Patch. Their technology in simple terms deploys buoyant tubes several kilometres in length. The project claim it can capture plastic ranging in size from tens of metres down to 1 cm.
  • It’s too early to say whether this could be a feasible contribution. You can follow their milestone journey here. They make some bold claims, stating that full deployment of the technology could remove 50% of the plastic within 5 years. The prototype has been proven at various small-scales and in the summer of 2018 launch their first cleanup system in the Great Pacific Garbage Patch. If all goes well, their timeline suggests they aim to expand globally in 2020.


According to, this is information on worms that can eat plastic:

  • In 2017 researchers discovered that the wax worm (the larvae of the wax moth) has the ability to break down polyethylene (PE).
  • PE accounts for around 40% of global plastics.
  • PE is largely non-degradable, but there have been a couple of previous instances where particular bacteria or fungi have been able to break it down at very, very slow rates.
  • This latest discovery of the wax worm, however, showed faster rates of breakdown — although still slow.
  • The researchers left 100 wax worms on a PE plastic bag for 12 hours and measured a 92 milligram breakdown of the plastic (about 3% of the plastic bag).
  • These rates are of course very slow, and at a tiny scale.
  • The plan wouldn’t be to scale-up the use of wax worms for plastic degradation — this would be unscalable.
  • However, this discovery could be useful in allowing us to identify a particular enzyme which breaks down plastics.
  • The authors suggest that wax worms break down the carbon-carbon bonds in PE either from the organism itself, or from the generation of a particular enzyme from its flora.
  • It could be possible to produce this enzyme or the bacteria which secrete this given enzyme at industrial scales.


According to, this is information on bacteria that can break down plastic:

  • There are particular strains of bacteria that are effective in breaking down plastic.
  • The most prominent discovery of this bacteria was made in Japan where researchers found a bacterium, Ideonella sakaiensis 201-F6, which could digest polyethylene terephthalate (PET) — the material used for single-use plastic bottles.
  • This bacterium does so by producing and secreting an enzyme called PETase.
  • PETase (a protein which accelerates reactions) can split certain chemical bonds in PET; the bacteria can then absorb the smaller molecules it left behind (which contain carbon, and can be used by the bacteria as fuel/food).
  • This breakthrough has been shown at very small laboratory scales.
  • However, the authors and researchers in this field are open about the fact that this is not a near-term solution and would take major technological and scientific developments before it can close to the scale that would have an impact.


Plastic Pollutes & Damages, But Is Also Beneficial In Several Ways – So, It’s Hard To Completely Ban It

  • It’s also important to note that plastic is a unique material with many benefits: it’s cheap, versatile, lightweight, and resistant. This makes it a valuable material for many functions. It can also provide environmental benefits through certain supply chains: it plays a critical role in maintaining food quality, safety and preventing waste. The trade-offs between plastics and substitutes (or complete bans are therefore complex and could create negative knock-on environmental impacts
  • Plastic can play a crucial role in many aspects: it is essential to preserving food quality, safety and shelf-life thereby preventing food wastage
  • Plastic plays across many aspects of society. It is a unique material: often lightweight, resilient, usually non-reactive, waterproof and cheap. One example where plastic plays an important role is food packaging. Whilst over-packaging can undoubtedly be a significant issue, packaging of food products is essential for the prevention of food losses, wastage and contamination. Storage and packaging plays a crucial role from harvest all the way through to final consumption of the foods we eat. Even if some consider the final phase of packaging (from retail to home) to be unnecessary, it is likely it has played an important role in preserving food from the farm to the retail stage. It protects foods from pest and disease, significantly increases shelf life, and maintains food safety.
  • Lack of packaging is a major contributor to lack of food security in low to medium income countries
  • In fact, studies have shown that when we compare environmental impacts such as greenhouse gas emissions, energy, water and resource use, plastic packaging tends to have a net positive impact. The impact of plastic production and handling is lower than the impacts which would result from food waste without packaging. Reducing packaging where it is used in excess is useful, however, abandoning packaging completely would have serious implications for food security, safety, and would ultimately lead to large increases in the environment impact of food.
  • The question is therefore: is plastic the best material to use for packaging? Which material is ‘best’ for the environment? As designer and sustainability innovator, Leyla Acaroglu, discusses in her TED Talk ‘Paper beats plastic? How to rethink environmental folklore’, there is no universal consensus on ‘best’ or ‘worst’ materials. Materials have different relative impacts across different environmental metrics. This ultimately leads to trade-offs. Some materials may release fewer greenhouse gas emissions but require more water or fertiliser inputs, for example.
  • There’s no simple answer; your choice would be different depending on the environmental impacts you’re most concerned about. In general, plastic tends to be cheap and has significantly lower greenhouse gas emissions, energy, water and fertilizer inputs than alternatives such as paper, aluminium, cotton or glass.
  • The obvious environmental detriment is it’s pollution of the natural environment when poorly managed. In the charts below we summarise one life-cycle analysis (LCA) study of environmental impacts by grocery bag type. This is based on results from the Danish Environmental Protection Agency.
  • These figures present the number of times a grocery bag would have to be reused to have as low an environmental impact as a standard LDPE (Low-density polyethylene) single-use plastic bag. For example, a value of 5 indicates a bag would have to be reused 5 times to equal the environmental impact of a standard single-use plastic bag.
  • Comparisons of alternatives to plastics and plastic bags can be found here –
  • This presents a complex decision: plastic tends to have lower environmental impact for most metrics with the exception of its non-degradability and marine pollution.



Plastic Trade – Importing & Exporting Of Plastic Between Countries

  • Plastic trade – the importing and exporting of plastic – has been significant in the past
  • China used to import and take in a lot of plastic from other countries, but has stated they are reducing and declining imports now

By 2030, it’s estimated that around 110 million tonnes of plastic will be displaced as a result of the China plastic ban. This plastic waste will have to be handled domestically or exported to another country. Brooks et al. (2018) suggest this ban has several implications:

  • exporting countries can use this as an opportunity to improve domestic recycled infrastructure and generate internal markets;
  • if recycling infrastructure is lacking, this provides further incentive for countries to reduce primary plastic production (and create more circular material models) to reduce the quantity of waste which needs to be handled;
  • it fundamentally changes the nature of global plastic trade, representing an opportunity to share and promote best practices of waste management, and harmonize technical standards on waste protocols;
  • some other countries may attempt to become a key plastic importer in place of China; one challenge is that many countries do not yet have sufficient waste management infrastructure to handle recycled waste imports;
  • countries considering importing significant quantities of plastic waste could consider an import tax specifically aimed at funding the development of sufficient infrastructure to handle such waste.

But there are 3 scenarios – 50%, 75% and 100% ban


Plastics can be challenging to recycle, particularly if they contain additives and a range of different plastic blends. The implications of this complexity are two-fold: in many cases it is convenient for countries to export their recycled plastic waste (meaning they don’t have to handle it domestically); and for importing countries, this plastic is often discarded if it doesn’t meet the sufficient requirements for recycled or is contaminated by non-recyclable plastic. As such, traded plastic waste could eventually enter the ocean through poor waste management systems.



Plastic & Landfill Disposal

  • Landfill is the dumping of plastic in landfill lots/areas
  • It’s important to distinguish between the quality/effectiveness of landfills.
  • The modern definition of a landfill is of a disposal site for materials through burial.
  • This is typically the case in high-income countries today where landfills are well-managed and effectively regulated.
  • However, across many countries today landfill resources can be poorly-managed; in many cases dumped in open landfills, pits or dumps.
  • Such uncontrolled disposal facilities can make plastics vulnerable to pollution of the surrounding environment and at risk of entering the ocean.
  • Well-managed landfill facilities have expectations to gather, compact and safely store waste. In many cases this involves covering or burying with soils or other materials.


However, such landfills still have negative environmental impacts:

Greenhouse gases: when organic matter decomposes to produce methane (CH4) and carbon dioxide (CO2) — both are greenhouse gases which contribute to climate change. In some landfill sites, methane gas can be captured and ‘flared’ (burned) for energy production. Plastic, which is hard to break down, degrades over very long timescales (particularly under low oxygen conditions) does not contribute to this effect.

Leachate: decomposing material can produce nutrient-rich or polluted waters which — if not properly contained — can leach to the surrounding environment and potentially enter waterways and soils. Well-managed landfills are usually surrounded by protective lining to prevent water leaching to the surrounding environment. However, local pollution can occur where this is not implemented effectively, or the lining breaks down and is not replaced.

Where plastics are not handled correctly, some types of plastic — such as polyvinyl chloride; PVC — can leach chemicals such as additives and plasticiser compounds. A report by the European Commission aimed to provide a detailed analysis and overview of the available evidence on the behaviour of PVC in landfills. The study concluded that whilst leachate of substances as either non-detectable or in very low concentrations, a precautionary approach would deem this material only controllable if landfills are equipped with adequate liner and leachate treatment.



Plastic and Incineration Disposal

  • Incineration is the burning of plastic
  • This is done at very high temperatures


What are the environmental impacts of incineration?

Greenhouse gases: the incineration of plastic produces carbon dioxide (CO2) — a primary driver of global climate change. However, the incineration process can be integrated as a ‘Waste to Energy’ (WtE) solution. WtE is a form of energy recovery; in this case energy from the plastics can be stored and utilised for energy. On a net balance, does incineration therefore have a net positive or negative impact on greenhouse gas emissions?

It depends. The relative gains from energy recovery vary depending on the efficiency of the incineration process in addition to the mix of energy sources it’s replacing. In countries where the energy mix is dominated by fossil fuels, incineration energy recovery can reduce emissions. However, across many countries — most across Europe — where incineration efficiency is low and the energy mix is lower-carbon, this does provide a net source of greenhouse gas emissions.

Air pollution: a common concern of incineration is that it releases toxic emissions to the surrounding environment. The burning of plastics can produce several toxic gases: incomplete combustion of Polyethylene (PE), Polypropylene (PP) and Polystyrene (PS) can release carbon monoxide (CO) and noxious emissions, while polyvinyl chloride (PVC) can produce dioxins.

Such gases can be toxic and dangerous to both human and ecosystem health. Open or uncontrolled burning of plastics should therefore be strongly avoided.

Is this also the case in incinerator facilities? It largely depends on the efficiency and environmental control of emissions of the particular incinerator site. In high-income countries in particular, waste management and incinerator sites are heavily regulated with monitoring of emissions and potential leaks to the surrounding environment.

Modern incinerators have largely dealt with the problem of dioxin or other toxin emissions.

Technologies here include efficient combustion, end-of-pipe treatment, selective catalytic reduction, and the addition of suitable inhibitors.

A study in Belgium, for example, reported no difference in dioxin-serum levels of maintenance workers of municipal waste incinerator facilities — individuals who would experience high exposure rates if such methods were not implemented.

However, such incinerator technologies and standards are not implemented everywhere — in countries where environmental regulation is less strict, unsafe or open burning of municipal waste remains common.

This typically occurs in low-t0-middle income countries.

Studies in India, Kenya and Thailand, for example, report notable pollution from the burning of waste (including the generation of dioxins).

For incineration to become a universally safe solution, standards and uptake of appropriate technologies and approaches must be adopted globally.


Recycling, Landfill or Incineration for Plastics Disposal?

  • With these being the three main options for plastic disposal – it makes sense to know the benefits and drawbacks of each
  • Each has it’s own environmental, health or economic issues, and depending on who you ask and where their agenda lies – each disposal method can be appealing or non appealing
  • Impact of different methods can be assessed across multiple factors including greenhouse gas emissions, energy use, local pollution, and cost of processing.
  • In terms of relative global warming potential (GWP) and total energy use (TEU) of the three methods, Recycling had the lowest global warming potential and energy use across nearly all of the studies
ReferenceMaterial/applicationGlobal warming potential (GWP)
Total energy use (TEU)
Arena et al. 2003PE and PET liquid containersR-L-IR-I-L
Beigl and Salhofer 2004Plastic packagingR-I
Chilton et al. 2010PETR-I
Craighill and Powell 1996PET, HDPE and PVCR-L
Dodbiba et al. 2008Plastics (PE, PS and PVC)R-I
Eriksson and Finnveden 2009Non-recyclable plasticI-L
Eriksson et al. 2005PE
PE, PP, PS, and PET
Finnveden et al. 2005PVC
Foolmaun and Ramjeeawon 2013PETR-L-IR-I-L
Grant et al. 2001PET, HDPE AND PVCR-LR-L
Moberg et al. 2005PETR-I-LR-I-L
Mølgaard 1995Plastics

Perigini et al. 2004PE and PET liquid containersR-L-IR-I-L
Perigini et al. 2005PE and PET liquid containersR-L-IR-I-L
Rajendran et al. 2013PlasticsR-I
Wenisch et al. 2004PlasticsR=L
Wollny et al. 2001Plastic packagingR-L-IR-I-L
M. Al-Maaded et al. 2012Plastics, non-specified

Shonfield 2008PlasticsI-L-R

– Credit:


From an environmental perspective, recycling is usually the best option. This typically holds true, but note that there are a few caveats:

  • this is based on the assumption that recycled material is a one-for-one displacement of primary plastic production, i.e. each tonne of recycled material prevents one tonne of primary material being produced.
  • However, this is not always the case. Recycling processes can often lead to products of lower quality and economic value — often termed ‘downcycling’. This means that we cannot take for granted that this substitution for primary production is one-to-one.
  • Much of the plastic we recycle can only be recycled once or twice. Then it will end up in landfill or incinerated. This means that whilst recycling is the best of the three management options, it’s not a silver bullet.
  • Recycling only delays — rather than prevents — disposal in landfill or incineration.
  • Whilst recycling has clear environmental benefits, it’s not always the most economically-favourable choice.
  • The relative profitability between recycling and the production of new plastic is strongly determined by oil prices. When oil prices are low, it can be cheaper to make raw plastics than to recycle. For example, when crude oil prices were low in 2015-16, the recycling industry struggled to compete with raw material production.
  • Nonetheless, recycling in general is the best of the three options.


Plastics can be challenging to recycle, particularly if they contain additives and a range of different plastic blends.

The implications of this complexity are two-fold: in many cases it is convenient for countries to export their recycled plastic waste (meaning they don’t have to handle it domestically); and for importing countries, this plastic is often discarded if it doesn’t meet the sufficient requirements for recycled or is contaminated by non-recyclable plastic.

As such, traded plastic waste could eventually enter the ocean through poor waste management systems.

But what about the plastic that is not recyclable — should we send it to landfill or incinerate?

Here, the winner is less clear-cut. As we see across the range of studies above: it depends on context, plastic type and conditions as to whether landfill or incineration has lower impact in terms of greenhouse gas emissions or energy use.

Both landfill and incineration have potential environmental risks if they’re not managed or regulated correctly. The best choice may depend on local context.

Incineration for example, can have a net positive on greenhouse gas emissions if burned efficiently and is utilised in a fossil fuel dominant energy mix. Across some countries — many across Europe — incineration efficiency is low and the energy mix is lower-carbon, meaning landfill may be more favourable.

Incineration may be favourable where fossil fuels are dominant, landfill space is limited or poorly managed, or subsurface conditions are unfavourable to landfills.

In either case it’s critical that proper management and regulation is in place to minimise environmental impacts.

Can recycling end up in landfill?

Unfortunately, yes. Some plastics intended for recycling end up in landfill.

There are several reasons why this can occur:

  1. In most countries, some share of plastics intended for recycling are eventually rejected at local or regional waste handling facilities. The most common reason for rejected recycling is the ‘contamination’ of recycling streams this can result from high concentrations of non-recyclable items in the waste stream, or contamination of other forms such as food waste. Even in cases where plastic contamination could be dealt within, it is sometimes more economically-feasible to divert some loads to landfill. Processing costs of poorly-sorted or contaminated plastic loads are more expensive, in some cases outweighing profits from recycled materials.The rate of ‘rejected recycling’ can vary significantly between countries depending on recycling policies, targets and the effectiveness of recycling separation methods (either at the household and local collection level, or at waste handling facilities). For a sense of scale, latest figures For England estimate that between 3 to 4 percent of total household recycling (which is plastics but also paper, metals etc.) was rejected and sent to landfill or incineration. In relative terms, this share is relatively low but could be improved through better understanding of how to avoid contamination of plastic recycling streams.
  2. Recycled plastic is a globally traded commodity. The majority of major exporters are high-income countries. If we look at the top ten exporting countries over the period from 1988 to 2016, we see that collectively they account for 78 percent of global plastic exports (as shown in the chart below). All of the top ten exporters are defined as high-income. Collectively, they have exported 168 million tonnes over this period, equivalent to an economic value of US$65 billion. China has been the world’s largest plastic importer. Collectively, China and Hong Kong have imported 72.4 percent of all plastic waste (with most imports to Hong Kong eventually reaching China). In 2017, China introduced a ban on non-industrial plastic imports in part because of the levels of contaminated plastics in countries’ export stream. Some of this imported plastic therefore ended up in landfill (and possibly at risk of entering the ocean).It’s challenging to track the ultimate fate of traded plastics, however it’s likely that at least some of recycled plastics exported from high-income countries enters landfill in the countries to which they are traded.
  3. Following China’s ban on imported plastic in 2017, previous large exporters such as the United States, Canada, Australia and UK have failed to handle the increase in domestic plastic recycling demand. As such, some materials intended for recycling have subsequently been diverted to landfill.
  4. Plastics typically degrade in quality during the recycling process. For most recyclable plastics, they are typically only suitable for recycling once. As a result, most recycled plastic we use eventually reaches landfill, even if it goes through an additional use cycle as another product. Recycling typically delays rather than prevents plastic disposal to landfill or incineration.



More On Recycling Of Plastic

  • Make sure you check with your local council the best way to recycle
  • Different plastics can be recycled differently – The structure of the polymers also affect a plastic’s recyclability. Some polymers fail and break down under mechanical or thermal stress; this affects their ability to be recycled. Refer to graphic on this page for materials that are recyclable –
  • In practice, the majority of recycled plastics are only recycled once or twice before being finally disposed of in landfill or incineration. In recent years there has been promising progress in the development of polymer materials which can be chemically recycled back to their initial raw materials for the production of virgin plastic production. In a recent study, Zhu et al. (2018) successfully synthesised a plastic with mechanical properties similar to commercially available plastics, but with infinite recyclability through chemical recycling. Such methods are currently expensive and unfavourable in terms of energy inputs, but could provide a commercially-viable solution in the years to follow.



Other Plastic Notes

  • Many plastics are defined as non-degradable, meaning they fail to decompose and are instead broken down into smaller and smaller particles. Materials can slowly break down through photodegradation (from UV radiation). Estimated decomposition times for plastics and other common marine debris items are shown in the chart below.
  • Fishing lines, for example, take an estimated 600 years to break down. Plastic bottles take an estimated 450 years.
  • Average decomposition time of different plastics can be found in –
  • There are bio degradable and oxo degradable plastics. The production of so-called ‘bioplastics’ or biodegradable plastics is currently very low: estimated at around 4 million tonnes per year (which would be just over one percent of global plastics production).
  • A key current challenge of biodegradable plastics is that they tend to need particular waste management methods which are not always widely available. In 2015, the United Nations Environment Programme (UNEP) published a report on the misconceptions, concerns and impacts of biodegradable plastics. It concluded that: “the adoption of plastic products labelled as ‘biodegradable’ will not bring about a significant decrease either in the quantity of plastic entering the ocean or the risk of physical and chemical impacts on the marine environment, on the balance of current scientific evidence.”
  • There’s new plastic based technology and solutions like bacteria that eats plastic
  • There are both primary and secondary microplastics
  • One challenge of micro-plastics is that their small size makes them easier to (consciously or not) ingest. Ingestion of micro-plastics could have detrimental impacts on wildlife health.




1. Hannah Ritchie and Max Roser (2018) – “Plastic Pollution”. Published online at Retrieved from: ‘’ [Online Resource]




What Elon Musk Said On The Joe Rogan Experience About Climate Change, Carbon Emissions, Sustainable Energy & Electric Cars

Elon Musk was on the Joe Rogan Experience today, and they covered some important topics such as Climate Change, Carbon Emissions, Sustainable Energy, Electric Cars and much more.

The following are some interesting paraphrased quotes from Elon Mush on the Joe Rogan Experience on Thursday 6th September, 2018:


Electric cars are important, solar energy is important, stationary storage of energy is important


It’s important that we accelerate the transition to sustainable energy. That’s why electric cars matter, whether electric cars happen sooner or later


We’re really playing a crazy game here with the atmosphere and the oceans. We’re taking vast amounts of carbon from deep underground, and putting this in the atmosphere – this is crazy! We should not do this. It’s very dangerous


The bizarre thing is that we are going to run out of oil long term. There’s only so much oil we can mine and burn. We must have a sustainable energy transport and infrastructure in the long term – we know that’s the end point. We know that. So, why run this crazy experiment, where we take trillions of tonnes of carbon from underground, and put it in the atmosphere and oceans. This is an insane experiment. This is the dumbest experiment in human history. Why are we doing this…it’s crazy!


The thing is – oil, coal, gas…it’s easy money.


It’s very difficult to put C02 back in the ground, it doesn’t like being in solid form, it takes a lot of energy[in answer to Joe Rogan’s questioning about clean coal].


The more carbon we take out of the ground, and it gets added to the atmosphere, and a lot of it gets permeated into the oceans, the more dangerous it is. I think we are OK right now…we can probably even add some more. But, the momentum towards sustainable energy is too slow.


There’s a vast base of industry, vast transportation industry. There’s 2.5 billion cars and trucks in the world. And new car and truck production – if it was 100% electric, that’s only about 100 million per year [new cars and trucks produced]. So, if you could snap your fingers, and turn all cars and trucks electric, it would still take 25 years, to change the transport base to electric. Make sense? Because how long does it take for a car or truck to go into the junk yard and get crushed? About 20-25 years.


[Joe asks – is there a way to accelerate the electric vehicle transition process – via subsidies, or encouragement from the government for example] Elon says – the thing is, what is going on now is there is an inherent subsidy in any oil burning device, any power plant or car, is fundamentally consuming the carbon capacity of the oceans and atmosphere…or just say atmosphere for short.


So, you can say there is a certain probability of something bad happening past a certain carbon concentration in the atmosphere. And, so there’s some uncertain number where if we put too much carbon in the atmosphere, things overheat, oceans warm up, ice caps melt, ocean real estate becomes a lot less valuable…because it’s underwater. It’s not clear what that number is, but the scientific consensus is overwhelming.


I don’t know any serious scientist, in fact, quite literally zero, that don’t think that there’s a quite serious climate risk that we’re facing


There’s fundamentally a subsidy occurring with every fossil fuel burning thing – power plants, aircrafts, cars, even rockets.


With cars there’s definitely a better way – with electric cars, to generate the energy with photovoltaics. Because, we’ve got a giant thermonuclear reactor in the sky called the Sun – it’s great, it shows up every day, it’s very reliable. You can generate energy with solar panels, store it with batteries 24 hours a day. And then you can send it to the Poles, to the North, with high voltage lines. The Northern parts of the world tend to have a lot of hydropower as well.


Anyway, all fossil fuel powered things have an inherent subsidy, which is their consumption of the carbon capacity of the atmosphere, and oceans.


People tend to think – why should electric vehicles have a subsidy? But, they aren’t taking into account that all fossil fuel burning vehicles have a subsidy which is the environmental cost to earth…but, nobody is paying for it. We will all pay for it in the future though eventually. It’s just not paid for now.


[Joe asks what the bottleneck is with electric cars – is it battery capacity?] Elon says we have to scale up production, we have to make the car compelling, make it better than gasoline or diesel cars, make it go far enough, make it go fast.


[Joe asks what Elon sees when he thinks about the future of his companies – what he sees as bottlenecks to holding back innovation] Elon says that’s a good question, but he wishes politicians were better at science – that would help a lot. [Joe says that’s a problem – there’s no incentive for them to be good at science]. Elon agrees but says they are pretty good at science in China. The mayor of Beijing he believes has an environmental engineering degree and the deputy mayor has a physics degree. The mayor of Shanghai is really smart.


Water Scarcity: Causes, Effects, Solutions, Forecasts & Stats

Water Scarcity: Causes, Effects, Solutions & Stats

Water scarcity is made up of a number of water related factors and issues.

It is a term loosely thrown around by different organisations and media outlets, with different meanings depending on who is using it and in what context.

In this guide we outline what water scarcity is, the types of water scarcity, what causes it, the effects, countries affected, and solutions.


Summary – Water Scarcity

  • Water scarcity is a different measurement and indicator to water stress
  • Water stress is simply an indicator of water supplies vs water demand – expressed as low to high levels of water stress
  • Water scarcity occurs when water demand actually exceeds internal water resources i.e. a water stressed country or city is more likely to experience water scarcity
  • There’s a range of potential ways to measure water scarcity
  • There’s a range of types of water scarcity such as physical water scarcity, and economic water scarcity
  • Causes of water scarcity can vary, but could be a combination of any of the following overpopulation or a growth in population, lack of signifiacant/adequate freshwater supplies, lack of money to invest in tech and infrastructure used for accessing and maintaining freshwater, poor management of water resources or access to water resources, high usage/demand and increased consumption of water in all sectors (residential, commercial, industrial) and particularly agriculture, high temperatures and dry climates, climate change, droughts, lack of rainfall, or variability in rainfall, and natural events and natural disasters like floods which pollute or disrupt a water supply
  • One-third of the global population (2 billion people) live under conditions of severe water scarcity at least 1 month of the year
  • Half a billion people in the world face severe water scarcity all year round
  • Half of the world’s largest cities experience water scarcity
  • Water Demand is expected to outstrip supply by 40% in 2030, if current trends continue.
  • Scarcity can be expected to intensify with most forms of economic development, but, if correctly identified, many of its causes can be predicted, avoided or mitigated
  • Desalination plants and recycling and re-using grey water and waste water after treatment are just some of the options in developed countries to combat water scarcity
  • In developing countries, financial investment to address water pollution and contamination, human waste and treatment and hygiene infrastructure, fresh water supply etc. are required


What Is Water Scarcity, & Absolute Water Scarcity?

  • Water scarcity is the lack of fresh water resources to meet water demand.
  • The essence of global water scarcity is the geographic and temporal mismatch between freshwater demand and availability.


  • Water scarcity is more extreme than water stress, and occurs when water demand exceeds internal water resources.



Note that there is a difference between water scarcity, and absolute water scarcity – which we outline below.

Keep this in mind when you read stats about water scarcity.


Measuring Water Scarcity explains that there are 4 ways water scarcity might be measured and described:

1. One of the most commonly used measures of water scarcity is the ‘Falkenmark indicator’ or ‘water stress index’. This method defines water scarcity in terms of the total water resources that are available to the population of a region; measuring scarcity as the amount of renewable freshwater that is available for each person each year.

If the amount of renewable water in a country is below 1,700 m3 per person per year, that country is said to be experiencing water stress; below 1,000 m3 it is said to be experiencing water scarcity; and below 500 m3, absolute water scarcity.


2. An alternative way of defining and measuring water scarcity is to use a criticality ratio. This approach relaxes the assumption that all countries use the same amount of water, instead defining water scarcity in terms of each country’s water demand compared to the amount of water available; measuring scarcity as the proportion of total annual water withdrawals relative to total available water resources.

Using this approach, a country is said to be water scarce if annual withdrawals are between 20-40% of annual supply, and severely water scarce if they exceed 40%.


3. A third measure of water scarcity was developed by the International Water Management Institute (IWMI). This approach attempts to solve the problems listed above by including: each country’s water infrastructure, such as water in desalination plants, into the measure of water availability; including recycled water by limiting measurements of water demand to consumptive use rather than total withdrawals; and measuring the adaptive capacity of a country by assessing its potential for infrastructure development and efficiency improvements.

Using this approach, the IWMI classifies countries that are predicted to be unable to meet their future water demand without investment in water infrastructure and efficiency as economically water scarce; and countries predicted to be unable to meet their future demand, even with such investment, as physically water scarce.


4. A fourth approach to measuring water scarcity is the ‘water poverty index’. This approach attempts to take into account the role of income and wealth in determining water scarcity by measuring: (1) the level of access to water; (2) water quantity, quality, and variability; (3) water used for domestic, food, and productive purposes; (4) capacity for water management; and (5) environmental aspects. The complexity of this approach, however, means that it is more suited for analysis at a local scale, where data is more readily available, than on a national level.


You can read more about each approach and it’s limitations in’s guide.


Water Scarcity vs Water Stress

Water stress is the ratio of total withdrawals to total renewable supply in a given area. A higher percentage means more water users are competing for limited water supplies, and therefore that area/country is more stressed.

But water stress is just an indicator how how close a country might be getting to running out of water.

(You can read more about water stress and water stress related information in this guide)

On the other hand, a country is water scarce when water is not available to meet demand.


Types Of Water Scarcity

There’s two types of water scarcity:

Physical Water Scarcity

  • Results from inadequate natural water resources to supply a region’s demand
  • Around one fifth of the world’s population currently live in regions affected by Physical Water Scarcity, where there is inadequate water resources to meet a country’s or regional demand, including the water needed to fulfill the demand of ecosystems to function effectively.
  • It also occurs where water seems abundant but where resources are over-committed, such as when there is over development of hydraulic infrastructure for irrigation. Symptoms of physical water scarcity include environmental degradation and declining groundwater as well as other forms of exploitation or overuse.


  • can mean scarcity in availability due to physical shortage



Economic Water Scarcity

  • Can result in two ways…
  • Results from poor management of the sufficient available water resources
  • Or, results by a lack of investment in infrastructure or technology to draw water from rivers, aquifers or other water sources, or insufficient human capacity to satisfy the demand for water.
  • Found more often to be the cause of countries or regions experiencing water scarcity, as most countries or regions have enough water to meet household, industrial, agricultural, and environmental needs, but lack the means to provide it in an accessible manner.
  • One quarter of the world’s population is affected by economic water scarcity.
  • Economic water scarcity includes a lack of infrastructure, causing the people without reliable access to water to have to travel long distances to fetch water, that is often contaminated from rivers for domestic and agricultural uses.
  • Large parts of Africa suffer from economic water scarcity; developing water infrastructure in those areas could therefore help to reduce poverty.
  • Critical conditions often arise for economically poor and politically weak communities living in already dry environment.
  • Consumption increases with GDP per capita in most developed countries, and the average amount (per capita) is around 200–300 litres daily.
  • In underdeveloped countries (e.g. African countries such as Mozambique), average daily water consumption per capita was below 10 L.
  • This is against the backdrop of international organisations, which recommend a minimum of 20 L of water (not including the water needed for washing clothes), available at most 1 km from the household.
  • Increased water consumption is correlated with increasing income, as measured by GDP per capita. In countries suffering from water shortages water is the subject of speculation.


  • can mean scarcity in access due to the failure of institutions to ensure a regular supply, or
  • scarcity due to a lack of adequate infrastructure



What Causes Water Scarcity?

There’s many factors that can cause water scarcity including:

  • Overpopulation or a growth in population
  • Lack of freshwater reserves
  • Lack of money to invest in tech and infrastructure used for accessing freshwater
  • Poor management of water resources or access to water resources
  • High usage/demand and increased consumption of water in all sectors (residential, commercial, industrial) and particularly agriculture
  • High temperatures and dry climates
  • Climate change
  • Droughts
  • Lack of rainfall, or variability in rainfall
  • Natural events and natural disasters like floods which pollute or disrupt a water supply also offers other causes:

  • Partial or no satisfaction of expressed demand
  • Economic competition for water quantity or quality
  • Disputes between users of water sources
  • Irreversible depletion of groundwater
  • Negative impacts on the environment which impact water sources
  • Technically, there is a sufficient amount of freshwater on a global scale. However, due to unequal distribution (exacerbated by climate change) resulting in some very wet and some very dry geographic locations, plus a sharp rise in global freshwater demand in recent decades driven by industry, humanity is facing a water crisis.
  • The increasing world population, improving living standards, changing consumption patterns, and expansion of irrigated agriculture are the main driving forces for the rising global demand for water.
  • Climate change, such as altered weather-patterns (including droughts or floods), deforestation, increased pollution, green house gases, and wasteful use of water can cause insufficient supply
  • At the global level and on an annual basis, enough freshwater is available to meet such demand, but spatial and temporal variations of water demand and availability are large, leading to (physical) water scarcity in several parts of the world during specific times of the year. All causes of water scarcity are related to human interference with the water cycle. Scarcity varies over time as a result of natural hydrological variability, but varies even more so as a function of prevailing economic policy, planning and management approaches.
  • The total amount of easily accessible freshwater on Earth, in the form of surface water (rivers and lakes) or groundwater (in aquifers, for example), is 14.000 cubic kilometres (nearly 3359 cubic miles). Of this total amount, ‘just’ 5.000 cubic kilometres are being used and reused by humanity. Hence, in theory, there is more than enough freshwater available to meet the demands of the current world population of 7 billion people, and even support population growth to 9 billion or more. Due to the unequal geographical distribution and especially the unequal consumption of water, however, it is a scarce resource in some parts of the world and for some parts of the population.
  • Scarcity as a result of consumption is caused primarily by the extensive use of water in agriculture/livestock breeding and industry. People in developed countries generally use about 10 times more water daily than those in developing countries. A large part of this is indirect use in water-intensive agricultural and industrial production processes of consumer goods, such as fruit, oil seed crops and cotton. Because many of these production chains have been globalised, a lot of water in developing countries is being used and polluted in order to produce goods destined for consumption in developed countries.



Climate change and bio-energy demands are also expected to amplify the already complex relationship between world development and water demand



Effects Of Water Scarcity

The effects of water scarcity may not be so severe, but it can turn into absolute water scarcity if not managed properly.

Absolute water scarcity on the other hand can be detrimental to country or region. Some effects can involve:

  • Economic effects – lack of economic growth, and increased poverty
  • Health effects – malnutrition from lack of water and lack of water to grow food to eat, hygiene and sanitary related health issues
  • Environment effects – increased salinity, nutrient pollution, and the loss of floodplains and wetlands. Furthermore, water scarcity makes flow management in the rehabilitation of urban streams problematic.

There can also be flow on social impact from these effects such as threats to social health (diseases), safety (increased violence and war) and stability (loss of employment).

Humans, animals, plants and the greater natural environment and atmosphere can be impacted by scarcity of water.


How Much Of The World Is Affected By Water Scarcity?

  • One-third of the global population (2 billion people) live under conditions of severe water scarcity at least 1 month of the year
  • Half a billion people in the world face severe water scarcity all year round
  • Half of the world’s largest cities experience water scarcity


  • a total of 2.7 billion find water scarce for at least one month of the year



What’s The Future Forecast/Trend For Water Scarcity?

  • Water Demand is expected to outstrip supply by 40% in 2030, if current trends continue.
  • Scarcity can be expected to intensify with most forms of economic development, but, if correctly identified, many of its causes can be predicted, avoided or mitigated



Solutions To Water Scarcity

General solutions to water scarcity may include:

  • Getting access to additional freshwater sources
  • Investing in water technology and infrastructure in low income, and highly water stressed countries and regions
  • Controlling populations in human dense cities and urban locations
  • Controlling water pollution
  • Using water efficiently at the home, commercial and industrial levels
  • Governments having good water management plans now and in the future, and governments being more organised
  • Developing freshwater technology to be cheaper and more energy friendly e.g. desalination plants
  • Mitigating the impact of climate change
  • Having drought and other natural event management plans
  • Better co-operation between countries on shared or trans-boundary freshwater sources
  • Everyone in society treating water as a scare resource to be protected
  • + more


More specific solutions, per, may include:

  • Some countries have already proven that decoupling water use from economic growth is possible. For example, in Australia, water consumption declined by 40% between 2001 and 2009 while the economy grew by more than 30%. The International Resource Panel of the UN states that governments have tended to invest heavily in largely inefficient solutions: mega-projects like dams, canals, aqueducts, pipelines and water reservoirs, which are generally neither environmentally sustainable nor economically viable. The most cost-effective way of decoupling water use from economic growth, according to the scientific panel, is for governments to create holistic water management plans that take into account the entire water cycle: from source to distribution, economic use, treatment, recycling, reuse and return to the environment.
  • Construction of wastewater treatment plants and reduction of groundwater overdrafting appear to be obvious solutions to the worldwide problem; however, a deeper look reveals more fundamental issues in play.
  • Wastewater treatment is highly capital intensive, restricting access to this technology in some regions; furthermore the rapid increase in population of many countries makes this a race that is difficult to win.
  • As if those factors are not daunting enough, one must consider the enormous costs and skill sets involved to maintain wastewater treatment plants even if they are successfully developed.
  • Reducing groundwater overdrafting is usually politically unpopular, and can have major economic impacts on farmers. Moreover, this strategy necessarily reduces crop output, something the world can ill-afford given the current population.
  • At more realistic levels, developing countries can strive to achieve primary wastewater treatment or secure septic systems, and carefully analyse wastewater outfall design to minimize impacts to drinking water and to ecosystems. Developed countries can not only share technology better, including cost-effective wastewater and water treatment systems but also in hydrological transport modeling. At the individual level, people in developed countries can look inward and reduce over consumption, which further strains worldwide water consumption.
  • Both developed and developing countries can increase protection of ecosystems, especially wetlands and riparian zones. There measures will not only conserve biota, but also render more effective the natural water cycle flushing and transport that make water systems more healthy for humans.
  • A range of local, low-tech solutions are being pursued by a number of companies. These efforts center around the use of solar power to distill water at temperatures slightly beneath that at which water boils. By developing the capability to purify any available water source, local business models could be built around the new technologies, accelerating their uptake. For example, Bedouins from the town of Dahab in Egypt have installed Aqua Danial’s Water Stellar, which uses a solar thermal collector measuring two square meters to distill from 40 to 60 liters per day from any local water source.
  • This is five times more efficient than conventional stills and eliminates the need for polluting plastic PET bottles or transportation of water supply.



There is not a global water shortage as such, but individual countries and regions need to urgently tackle the critical problems presented by water stress.

Water has to be treated as a scarce resource, with a far stronger focus on managing demand. Integrated water resources management provides a broad framework for governments to align water use patterns with the needs and demands of different users, including the environment.



Stats On Water Scarcity

  • Around 1.2 billion people, or almost one-fifth of the world’s population, live in areas of scarcity. Another 1.6 billion people, or almost one quarter of the world’s population, face economic water shortage (where countries lack the necessary infrastructure to take water from rivers and aquifers). (FAO, 2007) via
  • Around 700 million people in 43 countries suffer today from water scarcity. (Global Water Institute, 2013)
  • Two thirds of the world’s population currently live in areas that experience water scarcity for at least one month a year. (Mekonnen and Hoekstra, 2016) via
  • By 2025, 1.8 billion people are expected to be living in countries or regions with absolute water scarcity, and two-thirds of the world population could be under water stress conditions. (UNESCO, 2012) via
  • With the existing climate change scenario, by 2030, water scarcity in some arid and semi-arid places will displace between 24 million and 700 million people. (UNCCD) via
  • A third of the world’s biggest groundwater systems are already in distress (Richey et al., 2015) via
  • Nearly half the global population are already living in potential waterscarce areas at least one month per year and this could increase to some 4.8–5.7 billion in 2050. About 73% of the affected people live in Asia (69% by 2050) (Burek et al., 2016) via







5. Hannah Ritchie and Max Roser (2018) – “Water Access, Resources & Sanitation”. Published online at Retrieved from: ‘’ [Online Resource]


Water Stress: Causes, Effects, Solutions, Forecast & Stats

Water Stress: Causes, Effects, Solutions & Stats

Water stress is tightly linked to other global water issues.

The reason it is important to know about and keep track of is, the more water stressed a country or region gets, the closer they get to a water shortage.

In this guide we look at what it is, what causes it, the effect it has, potential solutions, as well as other important stats and information about water stress.


Summary – Water Stress

  • Water stress can be an indication of how much pressure a city’s fresh water supplies are under, and how close they are to being depleted. Water stress can be measured in cubic meters of fresh water remaining per person, per year. The lower the measurement get, the more water stressed a region becomes
  • Causes of high water stress can include lack of natural or standard freshwater reserves, High water usage/demand and increased consumption of water in all sectors (residential, commercial, industrial) and particularly agriculture, population growth or high population density (like in big cities), high temperatures and dry climates, increasing temperatures, droughts, lack of rainfall, or variability in rainfall, and natural events and natural disasters like floods which pollute or disrupt a water supply
  • More than one in every six people in the world is water stressed, meaning that they do not have sufficient access to potable water.
  • Some estimates predict that by 2040, around 33 countries could face extreme water stress
  • Governments implementing short term and long term water conservation and water supply policies and actions are KEY to preventing water stress in the future – especially in dry, warm, low rainfall, drought prone cities with growing populations


What Is Water Stress?

A few different definitions and explanations of water stress are:

– Water stress is the ratio of total withdrawals to total renewable supply in a given area. A higher percentage means more water users are competing for limited water supplies, and therefore that area/country is more stressed –

– Water stress is defined based on the ratio of freshwater withdrawals to renewable freshwater resources. Water stress does not insinuate that a country has water shortages, but does give an indication of how close it maybe be to exceeding a water basin’s renewable resources. If water withdrawals exceed available resources (i.e. greater than 100 percent) then a country is either extracting beyond the rate at which aquifers can be replenished, or has very high levels of desalinisation water generation (the conversion of seawater to freshwater using osmosis processes). –

– According to the Falkenmark Water Stress Indicator, a country or region is said to experience “water stress” when annual water supplies drop below 1,700 cubic metres per person per year. At levels between 1,700 and 1,000 cubic meters per person per year, periodic or limited water shortages can be expected. When a country is below 1,000 cubic meters per person per year, the country then faces water scarcity . –


Water Stress Ratings & Scale

According to the WRI, countries can fit into the following ranges, based on ratio of water withdrawals to water supply in the country:

  • Low – less than 10% (i.e. the country is withdrawing less than 10% of their overall water supply)
  • Low To Medium – 10 to 20%
  • Medium To High – 20 to 40%
  • High – 40 to 80%
  • Extremely High – more than 80%

So, a country withdrawing more than 80% of their water supply would be classified as having extremely high water stress.



Causes Of Water Stress

It differs depending on the country. But general factors can include:

  • Lack of freshwater reserves
  • High usage/demand and increased consumption of water in all sectors (residential, commercial, industrial) and particularly agriculture
  • Population growth
  • High temperatures and dry climates
  • Climate change
  • Droughts
  • Lack of rainfall, or variability in rainfall
  • Natural events and natural disasters like floods which pollute or disrupt a water supply


Some of the other factors can include:

  • Rapidly growing populations will drive increased consumption by people, farms and companies
  • More people will move to cities, further straining supplies
  • An emerging middle class could clamor for more water-intensive food production and electricity generation



  • Another popular opinion is that the amount of available freshwater is decreasing because of climate change.



  • Every water-stressed country is affected by a different combination of factors. Chile, for example, projected to move from medium water stress in 2010 to extremely high stress in 2040, is among the countries more likely to face a water supply decrease from the combined effects of rising temperatures in critical regions and shifting precipitation patterns.
  • Botswana and Namibia sit squarely within a region that is already vulnerable to climate change. Water supplies are limited, and risk from floods and droughts is high. Projected temperature increases in southern Africa are likely to exceed the global average, along with overall drying and increased rainfall variability. On the water demand side, according to Aqueduct projections, a 40 to 70 percent—or greater—increase is expected, further exacerbating the region’s concerns.
  • Whatever the drivers, extremely high water stress creates an environment in which companies, farms and residents are highly dependent on limited amounts of water and vulnerable to the slightest change in supply. Such situations severely threaten national water security and economic growth.



  • By 2030, water demand is expected to exceed current supply by 40 percent, according to the Water Resources Group, an arm of the World Bank.
  • “In many parts of the world, water scarcity is increasing and rates of growth in agricultural production have been slowing,” United Nations Secretary-General Ban Ki-moon said in an address to mark World Water Day last month.
  • “At the same time, climate change is exacerbating risk and unpredictability for farmers, especially for poor farmers in low-income countries…These interlinked challenges are increasing competition between communities and countries for scarce water resources, aggravating old security dilemmas, creating new ones and hampering the achievement of the fundamental human rights to food, water and sanitation.”
  • Experts say water shortages aren’t solely about a planetary climate that is becoming warmer and drier. Much of the blame can also be laid on the mismanagement of existing water resources.
  • Many industrial processes use a staggering amount of water from start to finish. It takes about 270 gallons of water to produce $1 worth of sugar; 200 gallons of water to make $1 worth of pet food; and 140 gallons of water to make $1 worth of milk.

–, and


Effects Of Water Stress

Overall, higher water stress means freshwater reserves are being depleted, and the closer you get to very high water stress, the closer you get to a water shortage.

Water restrictions means there is less water for all activities in the residential, commercial and industrial sectors.

Water shortages means extreme restrictions on water, and in some cases no water is available either temporarily or permanently for a certain period of time.

There are negative social, economic, health and environmental effects because of this.

Agriculture, as a big user of water, has less water to grow food for the population. Other businesses also have less water for products and raw materials manufacture.

There may also be less drinking water, water for sanitation, and water for cleaning for households – all of which can effect health and hygiene.


Other effects can be:

  • Businesses, farms, and communities in countries affected by water stress in particular may be more vulnerable to water scarcity
  • Civil wars can break out in extreme circumstances
  • Dwindling water resources and chronic mismanagement forced 1.5 million people, primarily farmers and herders, to lose their livelihoods and leave their land, move to urban areas, and magnify Syria’s general destabilization.



How Much Of The World Is Affected By Water Stress

  • More than one in every six people in the world is water stressed, meaning that they do not have sufficient access to potable water.
  • Those that are water stressed make up 1.1 billion people in the world and are living in developing countries.
  • In 2006, about 700 million people in 43 countries were living below the 1,700 cubic metres of water per person, per year threshold.



Countries That Are Water Stressed

  • Water stress is ever intensifying in regions such as China, India, and Sub-Saharan Africa, which contains the largest number of water stressed countries of any region with almost one fourth of the population living in a water stressed country.
  • The world’s most water stressed region is the Middle East with averages of 1,200 cubic metres of water per person.
  • In China, more than 538 million people are living in a water-stressed region.
  • Much of the water stressed population currently live in river basins where the usage of water resources greatly exceed the renewal of the water source.



Forecasts & Trends For Water Stress Now & In The Future

Estimates have been done for 167 countries by 2040

WRI scored and ranked future water stress—a measure of competition and depletion of surface water—in 167 countries by 2020, 2030, and 2040. They found that 33 countries face extremely high water stress in 2040

It was found that Chile, Estonia, Namibia, and Botswana could face an especially significant increase in water stress by 2040. This means that businesses, farms, and communities in these countries in particular may be more vulnerable to scarcity than they are today.


You can check out for the forecast of water stressed countries by 2040, and a handy map which shows the forecasted water stress level of these countries.


Solutions To Water Stress

  • National and local governments must bring forward strong national climate action plans and support a strong international climate agreement
  • Governments must also respond with management and conservation practices that will help protect essential sustainable water resources for years to come.



  • In Australia, water consumption declined by 40% between 2001 and 2009 while the economy grew by more than 30%. The International Resource Panel of the UN states that governments have tended to invest heavily in largely inefficient solutions: mega-projects like dams, canals, aqueducts, pipelines and water reservoirs, which are generally neither environmentally sustainable nor economically viable. The most cost-effective way of decoupling water use from economic growth, according to the scientific panel, is for governments to create holistic water management plans that take into account the entire water cycle: from source to distribution, economic use, treatment, recycling, reuse and return to the environment.



  • Water reuse however poses some unique challenges. Strict water regulations, while providing necessary legislation around delivery of potable water to our homes, can create unnecessary barriers in use of wastewater for industry. Effluent water, known as ‘greywater’, is generated through wastewater municipal treatment plants, treated and discharged. Yet over 95% of grey water is simply discharged into surface ponds.
  • However greywater can provide a valuable opportunity for water reuse in non-potable applications within industry. Addressing regulatory standards would not only allow for efficient reuse of this greywater but reduce the burden on freshwater supplies. This policy has already shown great success in Singapore. Their Bedok NEWater reuse plant provides wastewater for industry, using GE’s ZeeWeed membrane technology to reliably remove suspended solids from water. Initiatives like this are why Singapore now boasts production of more than 100 million gallons a day of recycled water for industrial, commercial and domestic use.
  • Water reuse is not limited to a national scale. At Frito Lay’s Casa Grande facility, Arizona, they utilise a ZeeWeed membrane bioreactor and reverse osmosis system from GE that treats and recycles 648,000 gallons per day. This solution helped achieve ambitious renewable targets, including a 90% reduction in water and electricity usage. The plant has the distinction of being the first existing food manufacturing site in the United States to achieve LEED EB environmental Gold Certification.
  • Water reuse has also shown impressive benefits within the oil and gas industry. In 2015 the Carigali-PTTEPI Operating Company was honoured with an ecomagination award by General Electric, recognising its positive environmental impact for its success in water reuse on a natural gas platform in the Gulf of Thailand. By installing advanced GE cooling and chemical treatment technology the company were able to save 132,000 gallons of water and $52 million a year by reducing platform downtime.





2. .


4. Hannah Ritchie and Max Roser (2018) – “Water Access, Resources & Sanitation”. Published online at Retrieved from: ‘’ [Online Resource]




Best (& Most Effective) Ways To Reduce Your Own Personal Carbon Footprint

Best (& Most Effective) Ways To Reduce Your Carbon Footprint

You’ve probably read a few of these ‘reduce your carbon footprint’ guides before … and, so have we.

But, did you know that some guides might be giving you only the ‘low impact’ ways to reduce your footprint?

There’s been research done into what the best ways to reduce your carbon footprint are, and the approximate CO2e (kg of carbon dioxide equivalent) reduced per year by implementing these actions.

What was found was that there’s a clear difference between ‘high impact’, ‘moderate impact’ and ‘low impact’ actions.

It makes sense to seriously consider the high impact actions on an individual level, and through society as a whole.


Summary – Most Effective Ways To Reduce Personal Carbon Footprint

Some of the high impact ways listed below include:

  • Think about the number of children you have – each extra person in the world introduces new carbon emissions to the world
  • Think about how much you use your car, and consider how you can walk or ride around more (or catch public transport) – cars/individual conventional fuelled cars contribute to a lot of carbon emissions because they burn fossil fuels
  • Think about how often you fly in planes – taking less plane trips a year can reduce carbon emissions
  • Switch to renewable/green energy – if your house currently runs on coal or gas power, switching to solar or another renewable energy technology reduces emissions
  • Consider how you drive – buying a fuel efficient car, buying an electric car, or simply reducing the amount of braking and accelerating you do can all reduce emissions
  • Consider what your food diet looks like – meat, animals based products and processed foods all tend to have a high carbon footprint than plant based diets. It’s also worth noting that the highest offending carbon footprint meats tend to be beef, lamb, and pork, with chicken usually having a smaller carbon footprint


High Impact, Moderate Impact, & Low Impact Actions For Reducing Carbon Dioxide Emission Footprint

Seth Wynes and Kimberly Nicholas outline high impact, moderate impact and low impact ways to reduce carbon dioxide in terms of approximate CO2e reduced per year (in kg):

High Impact Actions

  • Have one fewer child – 23, 700 up to 117,  700 CO2e reduced per year (kg)
  • Live car free – 1000 up to 5300
  • Avoid one long range flight per year – 700 up to 2800
  • Purchase green energy – less than 100, up to 2500
  • Reduce effects of driving – 1190
  • Eat a plant based diet – 300 up to 1600

Moderate Impact Actions

  • Better home heating/cooling efficiency – 180
  • Install solar panels/renewable energy
  • Use public transportation, ride a bike, or walk
  • Buy energy efficient products
  • Conserve energy – 210
  • Reduce food waste – 370
  • Eat less meat – 230
  • Reduce consumption in general (of products)
  • Reuse – 5
  • Recycle – 210
  • Eat local – 0 up to 360

Low Impact Actions

  • Conserve water
  • Eliminate unnecessary travel
  • Minimize waste
  • Plant a tree – 6 up to 60
  • Compost
  • Purchase carbon offsets
  • Reduce lawn mowing
  • Eco tourism
  • Keep backyard chickens
  • Buy Eco labelled products
  • Calculate your home’s carbon footprint

Civic Actions

  • Spread awareness
  • Influence employer’s actions
  • Influence school’s actions

–, and

You can read more on their analysis into the climate mitigation gap at:



Further Solutions On Climate Change & Greenhouse Gas Emissions

We’ve also put together a guide on potential solutions for climate change and greenhouse gas emissions based issues, effects and impacts.

You might get some more ideas and insight into the issue by reading it.





Solutions To (& Options To Address) Climate Change & Greenhouse Gas Emissions

Solutions To Climate Change & Greenhouse Gas Emissions


The ideal goal for carbon emissions worldwide is to limit future warming to below a total increase of 2 degrees Celsius (which puts us in line with pre industrial revolution levels).

Whether we reach this goal or not is dependent on how aggressively we put in place and act on climate change and greenhouse gas emission solutions.

We look at some of these potential solutions below.

(*Note that no solution works on it’s own and no solution is completely perfect. It takes a comprehensive  and holistic approach with different solutions working together to reduce the effects of climate change)


Solutions To Climate Change & Greenhouse Gas Emissions – Summary

The one thing humans can control with climate change is the level of greenhouse gas emissions we emit in the future – we can reduce, or eliminate them altogether (bring emissions to zero).

The main causes behind human emissions of greenhouse gases (mainly carbon dioxide) is the burning of fossil fuels (coal, natural gas and oil) for:

  • electricity and heat production
  • transportation
  • industry (factories and production of goods and raw materials)
  • commercial and residential uses
  • and agriculture and clearing of land

The main approach to addressing these causes is:

  • Climate change mitigation – involves reducing or eliminating emissions, or creating carbon ‘sinks’ (absorbing carbon from the atmosphere)

Other approaches to addressing climate change are climate change adaptation, and climate engineering.


According to, we have 4 options:

  • Emissions reduction: reducing climate change by reducing greenhouse gas emissions.
  • Sequestration: removing carbon dioxide (CO2) from the atmosphere into permanent geological, biological or oceanic reservoirs.
  • Adaptation: responding to and coping with climate change as it occurs, in either a planned or unplanned way.
  • Solar geoengineering: large-scale engineered modifications to limit the amount of sunlight reaching the earth, in an attempt to offset the effects of ongoing greenhouse gas emissions.

Each embodies a large suite of specific options, with associated risks, costs and benefits. The four strategies can affect each other: for example, doing nothing to reduce emissions would require increased expenditure to adapt to climate change, and increased chances of future resort to geoengineering.


There are many ways to reduce emissions of CO2 and other warming agents, including shifting energy supply away from dependence on fossil fuels; energy efficiency in the domestic, industrial, service and transport sectors; reductions in overall demand through better system design; and efficient reductions in emissions of methane, nitrous oxide, halocarbon gases and black-carbon aerosols. Uptake of all of these options is happening now, and multiple studies have shown that they can be expanded effectively.

Ultimately, some climate change is inevitable and adaptation will definitely be required.

The more CO2 that is emitted in the next few decades, the stronger the adaptation measures that will be needed in future. There are limits to the adaptive capacities of both ecosystems and human societies, particularly in less developed regions. Thus, the decisions we make today on emissions will affect not only the future requirements for and costs of adaptation measures, but also their feasibility.



Solutions To Climate Change & Greenhouse Gas Emissions – Specific Examples




Commercial and Residential

Agriculture, Land Use and Forestry



Other Ideas and potential solutions from various sources might include…


Seth Wynes and Kimberly Nicholas outline high impact, moderate impact and low impact ways to reduce carbon dioxide in terms of approximate CO2e reduced per year (kg):

High Impact Actions

  • Have one fewer child – 23 700 up to 117 700 CO2e reduced per year (kg)
  • Live car free – 1000 up to 5300
  • Avoid one long range flight per year – 700 up to 2800
  • Purchase green energy – less than 100, up to 2500
  • Reduce effects of driving – 1190
  • Eat a plant based diet – 300 up to 1600

Moderate Impact Actions

  • Home heating/cooling efficiency – 180
  • Install solar panels/renewables
  • Use public transportation, ride a bike, or walk
  • Buy energy efficient products
  • Conserve energy – 210
  • Reduce food waste – 370
  • Eat less meat – 230
  • Reduce consumption in general (of products)
  • Reuse – 5
  • Recycle – 210
  • Eat local – 0 up to 360

Low Impact Actions

  • Conserve water
  • Eliminate unnecessary travel
  • Minimize waste
  • Plant a tree – 6 up to 60
  • Compost
  • Purchase carbon offsets
  • Reduce lawn mowing
  • Eco tourism
  • Keep backyard chickens
  • Buy Eco labelled products
  • Calculate your home’s carbon footprint

Civic Actions

  • Spread awareness
  • Influence employer’s actions
  • Influence school’s actions

–, and


Some specific solutions to mitigating GG emissions and climate change might include:

  • More efficient use of residential electronics, and new technology for household electronics
  • More efficient use of residential appliances
  • Retrofit residential HVAC
  • Tillage and residue management
  • Insulation retrofits for residential buildings
  • Hybrid cars
  • Waste recycling
  • Lighting – switch from incandescent to LED lights (residential)
  • Retrofit insulation (commercial)
  • Better motor systems efficiency for vehicles
  • Cropland nutrient management, particulary with fertilizer
  • Clinker substitution by fly ash
  • Electricity from landfill gas/methane
  • Efficiency improvements by different industries
  • Rice management
  • 1st generation biofuels
  • Small hydro
  • Reduced slash and burn agriculture conversion
  • Reduced pastureland conversion
  • Grassland management
  • Geothermal energy
  • Organic soil restoration
  • Building energy efficiency in new builds
  • 2nd gen biofuels
  • Degraded land restoration
  • Pastureland afforestation
  • Nuclear energy
  • Degraded forest reforestation
  • Low penetration wind technology and energy
  • Solar CSP technology and energy
  • Solar PV technology and energy
  • High penetration wind technology and energy
  • Reduced intensive agriculture conversion
  • Power plant biomass co-firing
  • Coal CCS new build
  • Iron and steel CCS new build
  • Coal CCS retrofit
  • Gas plant CCS retrofit



Ideas for mitigation in each sector where greenhouse gases come from might include:

  • eliminate the burning of coal, oil and, eventually, natural gas
  • invest in companies practicing carbon capture and storage
  • use plant-derived plastics, biodiesel, wind power, solar and renewable energy
  • Invest in building upgrades and new buildings – thicker and better insulation
  • Build Better roads
  • More efficient cement production processes – more efficient fuels to fire up the kilns
  • Less vehicle travel – more transit, bike and walking.
  • Better and less use of planes and jets
  • Buy less in general – energy is used to make all products, so it makes sense to cut back
  • Use more efficient lighting and appliances
  • Go vegetarian
  • Stop deforestation, and plant more trees
  • Work on overpopulation
  • Renewable energy experimentation
  • Biofuels, and hydrolisation
  • Geoengineering



  • Carbon taxes and carbon tariffs
  • Choose a utility company that generates at least half its power from wind or solar and has been certified
  • Insulate your home, and have more efficient heating and cooling
  • Offer tax credits for homes and businesses that install carbon efficient tech
  • Energy efficient appliances – refrigerators, washing machines, and other appliances, look for the Energy Star label
  • Saving water reduces carbon pollution, too. That’s because it takes a lot of energy to pump, heat, and treat your water. So take shorter showers, turn off the tap while brushing your teeth, and switch to WaterSense-labeled fixtures and appliances.
  • Eat the food you buy. Make less of it meat. Meat is resource intensive
  • Change to LEDs – LED lightbulbs use up to 80 percent less energy than conventional incandescents.
  • Pull all plugs and ‘idle’ devices
  • Gas-smart cars, such as hybrids and fully electric vehicles, save fuel and money. And once all cars and light trucks meet 2025’s clean car standards, which means averaging 54.5 miles per gallon, they’ll be a mainstay. For good reason: Relative to a national fleet of vehicles that averaged only 28.3 miles per gallon in 2011, Americans will spend $80 billion less at the pump each year and cut their automotive emissions by half.
  • Maintain cars -If all Americans kept their tires properly inflated, we could save 1.2 billion gallons of gas each year. A simple tune-up can boost miles per gallon anywhere from 4 percent to 40 percent, and a new air filter can get you a 10 percent boost.
  • Planes, trains and automobiles – choosing to live in walkable smart-growth cities and towns with quality public transportation leads to less driving, less money spent on fuel, and less pollution in the air. Less frequent flying can make a big difference, too. “Air transport is a major source of climate pollution,” Haq says. “If you can take a train instead, do that.”
  • Pay for carbon offsets



According to

  • To keep global temperature rise below the agreed 2°C, global carbon emission must peak in the next decade and from 2070 onward must be negative
  • The goal, with the Paris Agreement in mind, is limiting warming to 2℃ above pre-industrial levels. The Paris Agreement went further, aiming to “pursue efforts” towards a more ambitious goal of just 1.5℃. Given we’re already at around 1℃ of warming, that’s a relatively short-term goal.
  • The warming will slow to a potentially manageable pace only when human emissions are reduced to zero. The good news is that they are now falling in many countries as a result of programs like fuel-economy standards for cars, stricter building codes and emissions limits for power plants. But experts say the energy transition needs to speed up drastically to head off the worst effects of climate change
  • The energy sources with the lowest emissions include wind turbines, solar panels, hydroelectric dams and nuclear power stations. Power plants burning natural gas also produce fewer emissions than those burning coal. Using renewables can be costlier in the short term
  • Burning gas instead of coal in power plants reduces emissions in the short run, though gas is still a fossil fuel and will have to be phased out in the long run
  • “Clean coal” is an approach in which the emissions from coal-burning power plants would be captured and pumped underground. It has yet to be proven to work economically, but some experts think it could eventually play a major role.



  • Mitigation of climate change are actions to reduce greenhouse gas emissions, or enhance the capacity of carbon sinks to absorb greenhouse gases from the atmosphere.
  • There is a large potential for future reductions in emissions by a combination of activities, including energy conservation and increased energy efficiency; the use of low-carbon energy technologies, such as renewable energy, nuclear energy, and carbon capture and storage; and enhancing carbon sinks through, for example, reforestation and preventing deforestation.
  • A 2015 report by Citibank concluded that transitioning to a low carbon economy would yield positive return on investments.
  • Apart from mitigation, adaptation and climate engineering are other options for responses.



Climate change mitigation:

  • Mitigation involves reducing emissions, becoming more efficient with energy usage,  or increasing carbon sinks (reforestation)



Climate change adaptation:

  • Climate change adaptation is a response to global warming, that seeks to reduce the vulnerability of social and biological systems to relatively sudden change and thus offset the effects of global warming.
  • Even if emissions are stabilized relatively soon, global warming and its effects should last many years, and adaptation would be necessary to the resulting changes in climate.
  • Adaptation is especially important in developing countries since those countries are predicted to bear the brunt of the effects of global warming.
  • That is, the capacity and potential for humans to adapt (called adaptive capacity) is unevenly distributed across different regions and populations, and developing countries generally have less capacity to adapt.
  • Furthermore, the degree of adaptation correlates to the situational focus on environmental issues. Therefore, adaptation requires the situational assessment of sensitivity and vulnerability to environmental impacts



Climate engineering:

  • Climate engineering or climate intervention, commonly referred to as geoengineering, is the deliberate and large-scale intervention in the Earth’s climate system, usually with the aim of mitigating the adverse effects of global warming.
  • Climate engineering is an umbrella term for measures that mainly fall into two categories: greenhouse gas removal and solar radiation management.
  • Greenhouse gas removal approaches, of which carbon dioxide removal represents the most prominent subcategory addresses the cause of global warming by removing greenhouse gases from the atmosphere.
  • Solar radiation management attempts to offset effects of greenhouse gases by causing the Earth to absorb less solar radiation.
  • Some carbon dioxide removal practices, such as afforestation, ecosystem restoration and bio-energy with carbon capture and storage projects, are underway to a limited extent.
  • Most experts and major reports advise against relying on climate engineering techniques as a main solution to global warming, in part due to the large uncertainties over effectiveness and side effects. However, most experts also argue that the risks of such interventions must be seen in the context of risks of dangerous global warming.



According to Wikipedia:

  • Excess CO2 emitted since the pre-industrial era is projected to remain in the atmosphere for centuries to millennia, even after emissions stop. Even if human carbon dioxide emissions were to completely cease, atmospheric temperatures are not expected to decrease significantly for thousands of years.



1. IPCC Fifth Assessment Report –















16. Hannah Ritchie and Max Roser (2018) – “CO₂ and other Greenhouse Gas Emissions”. Published online at Retrieved from: ‘’ [Online Resource] 



Climate Change & Greenhouse Gas Emissions: Causes, Sources, Effects, Solutions & Forecasts

Climate Change: Causes, Sources, Effects, & Solutions

Climate change is one of the most talked about, if not the most talked about global issue.

When we talk about Climate Change, we also usually talk about global warming and greenhouse gases.

In this guide we outline what climate change is, the causes and sources, the effects, and what potential solutions might be on how to prevent it.

We also talk about how global warming and greenhouse gases tie into climate change as a whole.


Summary – What To Know About Climate Change

Climate change in a nutshell is the warming of the earth’s surface (via the sun’s solar radiation, and eventually infrared radiation) – with the warming process being amplified by greenhouse gases such as carbon dioxide (the main gas), but also methane, nitrous oxide and other gases.

From the evidence gathered, climate modelling done, and scientific formulas used – there is a consensus that humans are most likely the primary cause for the warming we are seeing today. Activities such as electricity production (that burns fossil fuels like coal), and vehicles (that burn petroleum) emit huge amounts of GHGs through burning of fossil fuels.

This warming period is usually expressed as the warming that has taken place since around 1950/60.

Temperatures have risen (up to 2019) around 0.8 to 0.9 degrees celcius compared to pre industrial levels, when carbon dioxide levels started increasing rapidly.

This rapid increase in carbon dioxide level (parts per million in the air) coincides with humans’ increased combustion of fossil fuels since the start of the industrial revolution.

What scientists do admit is that there are things they do know about climate change, things they think they might know, and things they are uncertain about that they can only make educated forecasts about with the information available.

They also admit that climate change feedback processes can be complex – leading to warming in some areas, and cooling in others (each area in the world has it’s own local or micro climate).

There’s also variables in the form of what we as humans will do in the future. What we do to mitigate emissions, adapt to changes, and reduce emissions will all impact how climate predictions can be made into the future.

As mentioned above, when it comes to climate change, a good way to look at it might be – what we are fairly certain we know, what we think we might know, and what we might be uncertain about.


What Is Climate Change?

  • Climate change is a change in the pattern of weather, and related changes in oceans, land surfaces and ice sheets, occurring over time scales of decades or longer



What Is Global Warming?

Global warming (i.e. an increase in the earth’s surface temperature) is just one factor in the overall climate change issue.

So, climate change is the all encompassing issue, whereas global warming is a ‘sub factor’ or ‘side effect’ in the overall issue.


What Is The Main Climate Change Problem?

It’s a very wide ranging problem with many factors and sub issues, causes, effects etc. to consider.

These factors and specific issues also differ country by country (and even state by state).

But, the core of the problem is the rise in the earth’s average surface temperature since the industrial revolution and particularly since the late 19th century, which has been largely driven by increased carbon dioxide and other human caused emissions in the atmosphere (carbon dioxide levels have sharply increased to unseen levels from 1950 to the current day).

A big cause for this is the burning of fossil fuels for electricity and heat production, transportation, industry (factories and production of goods and raw materials), and agriculture and clearing of land.


The planet’s average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century.

Most of the warming occurred in the past 35 years, with the five warmest years on record taking place since 2010. Not only was 2016 the warmest year on record, but eight of the 12 months that make up the year — from January through September, with the exception of June — were the warmest on record for those respective months.

Temperature is the one that gets all the attention, but there’s also other issues like:

  • Warming oceans
  • Shrinking ice sheets
  • Glacial retreat
  • Decreased snow cover
  • Sea level rise
  • Declining Arctic sea ice
  • Extreme/severe natural events
  • Ocean acidification
  • + more



What Are Greenhouse Gases?

Greenhouse gases are gases emitted from human and natural sources on earth, that rise up and sit in the earth’s atmosphere like a blanket.

This blanket of greenhouse gases lets through solar radiation from the sun (light). It also absorbs and re-emits infrared radiation (heat) from and back to the earth’s surface.

They get the name greenhouse gas because they have a similar effect that greenhouse glass has whereby the glass traps some IR radiation heat inside the greenhouse.

Greenhouse gases can be divided into two main types:

  • Greenhouse gases being emitted directly by human activities – Carbon dioxide (CO2) is the main one. Then methane (CH4), and nitrous oxide (N2O). Then others include ozone (O3), and synthetic gases (the ‘F’ gases), such as chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs)
  • Other greenhouse gases – Water vapour is also a major greenhouse gas, but its concentration in the atmosphere is not influenced directly by human activities (it is influenced indirectly though by the production of carbon dioxide).
  • The most important greenhouse gases are water vapour and carbon dioxide (CO2). Both are present at very small concentrations in the atmosphere.
  • The two most abundant gases in the atmosphere are nitrogen (comprising 78 per cent of the dry atmosphere) and oxygen (21 per cent), but they have almost no greenhouse effects.
  • Water vapour varies considerably in space and time because it has a short ‘lifetime’ in the atmosphere. Because of this variation, it is difficult to measure globally averaged water vapour concentration.
  • Carbon dioxide has a much longer lifetime and is well mixed throughout the atmosphere. The current concentration is about 0.04 per cent.



  • Today, human activities are directly increasing atmospheric concentrations of CO2, methane and nitrous oxide, plus some chemically manufactured greenhouse gases such as halocarbons.
  • These human generated gases enhance the natural greenhouse effect and further warm the surface.
  • In addition to the direct effect, the warming that results from increased concentrations of long-lived greenhouse gases can be amplified by other processes.
  • A key example is water vapour amplification. Human activities are also increasing aerosols in the atmosphere, which reflect some incoming sunlight. This human-induced change offsets some of the warming from greenhouse gases.



What Is The Greenhouse Gas Effect?

There are two main types of greenhouse gas effects:

  • The natural green house gas effect which happens via the natural carbon cycle
  • The enhanced greenhouse gas effect which happens via human activities that add carbon dioxide on top of the natural emission of carbon dioxide

The thing is – we need the natural carbon cycle and natural greenhouse gas effect to make earth habitable. Without it, the earth would be -18ºC (minus 18 degrees) – and the earth would be uninhabitable.

The problem is the enhanced/human induced greenhouse releases carbon into the atmosphere faster than it can be removed by other parts of the carbon cycle.

This is called the ‘greenhouse effect’, and the gases that cause it by interacting with infrared radiation are called greenhouse gases. The most important are water vapour (which humans can’t directly control), carbon dioxide (CO2) and methane.

Since the Industrial Revolution, energy-driven consumption of fossil fuels has led to a rapid increase in CO2 emissions, disrupting the global carbon cycle and leading to a planetary warming impact.



How Does The Greenhouse Effect Actually Work?

What happens in the greenhouse effect it:

  • Solar radiation (light) comes from the sun and is emitted onto the earth’s surface (the sun’s energy intensity and the distance of the sun from earth affect how much solar radiation we get)
  • This solar radiation hits the earth’s surface, is converted to IR radiataion (heat) and warms the earth
  • Some IR radiation is emitted back to space, and some of it does escape into space
  • Some IR radiation gets absorbed by greenhouse gases in the atmosphere and re-emitted back onto the earth’s surface and troposphere – causing more heating than normal
  • Greenhouse gases, particularly carbon, gather in the atmosphere at a higher rate due to human activity like burning fossil fuels than they would during the natural carbon cycle

You can see how this works visually here:

the greenhouse effect

Credit: Philippe Rekacewicz, Emmanuelle Bournay, UNEP/GRID-Arendal

Page Link:


  • The Sun serves as the primary energy source for Earth’s climate.
  • Some of the incoming sunlight is reflected directly back into space, especially by bright surfaces such as ice and clouds, and the rest is absorbed by the surface and the atmosphere.
  • Much of this absorbed solar energy is re-emitted as heat (longwave or infrared radiation).
  • The atmosphere in turn absorbs and re-radiates heat, some of which escapes to space. Any disturbance to this balance of incoming and outgoing energy will affect the climate. For example, small changes in the output of energy from the Sun will affect this balance directly.
  • If all heat energy emitted from the surface passed through the atmosphere directly into space, Earth’s average surface temperature would be tens of degrees colder than today. Greenhouse gases in the atmosphere, including water vapour, carbon dioxide, methane, and nitrous oxide, act to make the surface much warmer than this, because they absorb and emit heat energy in all directions (including downwards), keeping Earth’s surface and lower atmosphere warm.
  • Without this greenhouse effect, life as we know it could not have evolved on our planet.
  • Adding more greenhouse gases to the atmosphere makes it even more effective at preventing heat from escaping into space.
  • When the energy leaving is less than the energy entering, Earth warms until a new balance is established.



What Is The Natural Carbon Cycle, And The Natural Greenhouse Gas Effect?

The natural cycle of carbon emission and absorption into and out of the atmosphere by living things and the natural environment.

All living organisms contain carbon, as do gases (such as carbon dioxide) and minerals (such as diamond, peat and coal). The movement of carbon between large natural reservoirs in rocks, the ocean, the atmosphere, plants, soil and fossil fuels is known as the carbon cycle.

The carbon cycle includes the movement of carbon dioxide:

  • into and out of our atmosphere
  • between the atmosphere, plants and other living organisms through photosynthesis, respiration and decay
  • between the atmosphere and the top of the oceans.

On longer time scales, chemical weathering and limestone and fossil fuel formation decrease atmospheric carbon dioxide levels, whereas volcanoes return carbon to the atmosphere. This is the dominant mechanism of control of carbon dioxide on timescales of millions of years.

Because the carbon cycle is essentially a closed system, any decrease in one reservoir of carbon leads to an increase in others.

For at least the last several hundred thousand years, up until the Industrial Revolution, natural sources of carbon dioxide were in approximate balance with natural ‘sinks’, producing relatively stable levels of atmospheric carbon dioxide.

‘Sinks’ are oceans, plants and soils, which absorb more carbon dioxide than they emit (in contrast, carbon sources emit more than they absorb).



What Is The Human/Enhanced Greenhouse Gas Effect?

Greenhouse gases (mainly carbon dioxide) emitted into the atmosphere mainly by human activity.

Refer to the ’causes’ section below for the sources of these carbon dioxide emissions.

The total carbon cycle is the natural carbon cycle and human carbon cycle together. That can be seen here:

total carbon cycle

Credit: Philippe Rekacewicz, Emmanuelle Bournay, UNEP/GRID-Arendal



Why Is Carbon Dioxide Considered The Main Greenhouse Gas?

There’s two reasons for this:

  • CO2 is responsible for more of an increase in the amount of energy (and therefore heat) reaching Earth’s surface than the other greenhouse gases. Other gases have more potent heat-trapping ability molecule per molecule than CO2 (e.g. methane), but are simply far less abundant in the atmosphere.
  • CO2 remains in the atmosphere longer than the other major heat-trapping gases


Explained in deeper detail…

  • Greenhouse gases are climate drivers
  • By measuring the abundance of heat-trapping gases in ice cores, the atmosphere, and other climate drivers along with models, the IPCC calculated the “radiative forcing” (RF) of each climate driver—in other words, the net increase (or decrease) in the amount of energy reaching Earth’s surface attributable to that climate driver.
  • Positive RF values represent average surface warming and negative values represent average surface cooling. In total, CO2 has the highest positive RF (see Figure 1) of all the human-influenced climate drivers compared by the IPCC.
  • Other gases have more potent heat-trapping ability molecule per molecule than CO2 (e.g. methane), but are simply far less abundant in the atmosphere.
  • CO2 remains in the atmosphere longer than the other major heat-trapping gases emitted as a result of human activities. It takes about a decade for methane (CH4) emissions to leave the atmosphere (it converts into CO2) and about a century for nitrous oxide (N2O).
  • After a pulse of CO2 is emitted into the atmosphere, 40% will remain in the atmosphere for 100 years and 20% will reside for 1000 years, while the final 10% will take 10,000 years to turn over. This literally means that the heat-trapping emissions we release today from our cars and power plants are setting the climate our children and grandchildren will inherit.
  • Water vapor is the most abundant heat-trapping gas, but rarely discussed when considering human-induced climate change. The principal reason is that water vapor has a short cycle in the atmosphere (10 days on average) before it is incorporated into weather events and falls to Earth, so it cannot build up in the atmosphere in the same way as carbon dioxide does.
  • However, a vicious cycle exists with water vapor, in which as more CO2 is emitted into the atmosphere and the Earth’s temperature rises, more water evaporates into the Earth’s atmosphere, which increases the temperature of the planet. The higher temperature atmosphere can then hold more water vapor than before.



Explained in another way…

  • Carbon dioxide is not the only greenhouse gas of concern for global warming and climatic change. There are a range of greenhouse gases, which include methane, nitrous oxide, and a range of smaller concentration trace gases such as the so-called group of ‘F-gases’.
  • Greenhouse gases vary in their relative contributions to global warming; i.e. one tonne of methane does not have the same impact on warming as one tonne of carbon dioxide. These differences can be defined using a metric called ‘Global Warming Potential’ (GWP). GWP can be defined on a range of time-periods, however the most commonly used (and that adopted by the IPCC) is the 100-year timescale (GWP100).
  • You can look at the GWP100 value of key greenhouse gases relative to carbon dioxide. The GWP100metric measures the relative warming impact one molecule or unit mass of a greenhouse gas relative to carbon dioxide over a 100-year timescale. For example, one tonne of methane would have 28 times the warming impact of tonne of carbon dioxide over a 100-year period. GWP100 values are used to combine greenhouse gases into a single metric of emissions called carbon dioxide equivalents (CO2e). CO2e is derived by multiplying the mass of emissions of a specific greenhouse gas by its equivalent GWP100 factor. The sum of all gases in their CO2e form provide a measure of total greenhouse gas emissions.
  • We see the contribution of different gases to total greenhouse gas emissions. These are measured based on their carbon-dioxide equivalent values. Overall we see that carbon dioxide accounts for around three-quarters of total greenhouse gas emissions. However, both methane and nitrous oxide are also important sources, accounting for around 17 and 7 percent of emissions, respectively.
  • Collectively, HFC, PFC and SF6 are known as the ‘F-gases’. Despite having a very strong warming impact per unit mass (i.e. a high global warming potential), these gases are emitted in very small quantities; they therefore make only a small contribution to total warming.



  • Carbon dioxide is the largest single contributor to human-induced climate change. NASA describes it as ‘the principal control knob that governs the temperature of Earth’. Although other factors (such as other long-lived greenhouse gases, water vapour and clouds) contribute to Earth’s greenhouse effect, carbon dioxide is the dominant greenhouse gas that humans can control in the atmosphere.



  • Scientists have determined that, when all human and natural factors are considered, Earth’s climate balance has been altered towards warming, with the biggest contributor being increases in CO2.



Do Humans Only Affect Climate Change Through Greenhouse Gases?


  • Greenhouse gases emitted by human activities alter Earth’s energy balance and thus its climate.
  • But, humans also affect climate by changing the nature of the land surfaces (for example by clearing forests for farming) and through the emission of pollutants that affect the amount and type of particles in the atmosphere.



Causes Of Climate Change (Sources, Sectors & Countries)

The main driver/cause of climate change is carbon emissions from human activity.

These human activities mainly include the burning of fossil fuels – for vehicles, for electricity generation at power plants and so on.

Water vapour accounts for about half the present-day greenhouse effect, but its concentration in the atmosphere is not influenced directly by human activities. The amount of water in the atmosphere is related mainly to changes in the Earth’s temperature. For example, as the atmosphere warms it is able to hold more water. Although water vapour absorbs heat, it does not accumulate in the atmosphere in the same way as other greenhouse gases; it tends to act as part of a feedback loop rather than being a direct cause of climate change.

So, let’s get more specific about where carbon dioxide comes from according to different sources:

EPA tracks total U.S. emissions by publishing the Inventory of U.S. Greenhouse Gas Emissions and Sinks. This annual report estimates the total national greenhouse gas emissions and removals associated with human activities across the United States.

The primary sources of greenhouse gas emissions in the United States are –

  • Transportation – nearly 28.5 percent of 2016 greenhouse gas emissions
  • Electricity Production – 28.4 percent of 2016 greenhouse gas emissions
  • Industry – 22 percent of 2016 greenhouse gas emissions
  • Commercial and residential – 11 percent of 2016 greenhouse gas emissions
  • Agriculture – 9 percent of 2016 greenhouse gas emissions
  • Land Use And Forestry – offset of 11 percent of 2016 greenhouse gas emissions



Combustible fossil fuels such as coal, power plant gas, oil, vehicles and big industry are the largest source of carbon dioxide. The production is from various items such as iron, steel, cement, natural gas, solid waste combustion, lime, ammonia, limestone, cropland, soda ash, aluminum, petrochemical, titanium and phosphoric acid. Carbon dioxide accounts for nearly 85 percent of all emissions and is produced when natural gas, petroleum and coal are used. The major areas where these fuels are used include electricity generation, transportation, industry and in residential and commercial buildings.



87 percent of all human-produced carbon dioxide emissions come from the burning of fossil fuels like coal, natural gas and oil. The remainder results from the clearing of forests and other land use changes (9%), as well as some industrial processes such as cement manufacturing (4%).

– Further breakdown at


Since the Industrial Revolution there has been a large increase in human activities such as fossil fuel burning, land clearing and agriculture, which affect the release and uptake of carbon dioxide.

According to the most recent Emissions Overview, carbon dioxide and other greenhouse gases are produced in NSW (in Australia) by the following activities or sources:

  • stationary energy sources, such as coal-fired power stations (47 per cent)
  • transport (18 per cent)
  • coal mines (12 per cent)
  • agriculture (11 per cent)
  • land use (7 per cent)
  • land change (3 per cent)
  • waste (2 per cent).

Carbon dioxide released into the atmosphere from burning fossil fuels carries a different chemical fingerprint from that released by natural sources such as respiration and volcanoes. This makes it possible to identify the contribution of human activity to greenhouse gas production.

Data collected by CSIRO show that the concentration of carbon dioxide in our atmosphere in 2018 was approximately 404 parts per million. The level of carbon dioxide in the Earth’s atmosphere is now higher than at any time over the past 800,000—and possibly 20 million—years.

Global atmospheric concentrations of the other greenhouse gases (methane and nitrous oxide) also now exceed pre-industrial values.



Global greenhouse gas emissions can be broken down by sectoral sources in these sections:

  • Energy (energy, manufacturing and construction industries and fugitive emissions): emissions are inclusive of public heat and electricity production; other energy industries; fugitive emissions from solid fuels, oil and gas, manufacturing industries and construction.
  • Transport: domestic aviation, road transportation, rail transportation, domestic navigation, other transportation.
  • International bunkers: international aviation; international navigation/shipping.
  • Residential, commercial, institutional and AFF: Residential and other sectors.
  • Industry (industrial processes and product use): production of minerals, chemicals, metals, pulp/paper/food/drink, halocarbons, refrigeration and air conditioning; aerosols and solvents; semicondutor/electronics manufacture; electrical equipment.
  • Waste: solid waste disposal; wastewater handling; waste incineration; other waste handling.
  • Agriculture: methane and nitrous oxide emissions from enteric fermentation; manure management; rice cultivation; synthetic fertilizers; manure applied to soils; manure left on pasture; crop residues; burning crop residues, savanna and cultivation of organic soils.
  • Land use: emissions from the net conversion of forest; cropland; grassland and burning biomass for agriculture or other uses.
  • Other sources: fossil fuel fires; indirect nitrous oxide from non-agricultural NOx and ammonia; other anthropogenic sources.



Emissions by country…

Cumulative emissions –  As of 2014 – China’s rapid growth in emissions over the last few decades now makes it the world’s second largest cumulative emitter, although it still comes in at less than 50% of the US total.

Annual emissions – In 2014, we can see that a number of low to middle income nations are now within the top global emitters. In fact, China is now the largest emitter, followed by (in order) the US, EU-28, India, Russia, Indonesia, Brazil, Japan, Canada and Mexico. Note that a number of nations that are already top emitters are likely to continue to increase emissions as they undergo development.

In contrast to CO2 emissions growth in low to middle income economies, trends across many high income nations have stabilized, and in several cases decreased in recent decades. Despite this downward trend across some nations, emissions growth in transitioning economies dominates the global trend—as such, global annual emissions have continued to increase over this period.

Per Capita emissions – With a few exceptions, there is an important north-south divide in terms of per capita emissions. Most nations across sub-Saharan Africa, South America and South Asia have per capita emissions below five tonnes per year (many have less than 1-2 tonnes). This contrasts with the global north where emissions are typically above five tonnes per person (with North America above 15 tonnes). The monthly emissions per capita in rich countries are mostly higher than the yearly emissions per capita in poorer countries. The largest emitter, Qatar, has per capita emissions of 50 tonnes per year (1243 times that of Chad, the lowest emitter).

Note that carbon dioxide is not the only greenhouse gas which contributes to climate change—nitrous oxide and methane are also greenhouse gases, but are not included here. Food production, especially intensive livestock-rearing for meat and dairy, is a major contributor to both of these non-CO2 GHGs. Since capita meat intake is strongly linked to GDP levels, per capita emissions of nitrous oxide and methane tend to be much larger in high-income nations.

C02 emissions by source vary depending on the country – we are talking about gas, liquid (i.e. oil), solid (coal and biomass), flaring, and cement production. In the present day, solid and liquid fuel dominate, although contributions from gas production are also notable. Cement and flaring at the global level remain comparably small. has some great missions charts and graphs which show total GHG emissions, as well as Carbon Dioxide, Methane and Nitrous Oxide Emissions by sector, activity, country and more as %’s, parts per million etc. –

You can see the stats, as well as trends of emissions.

The EPA has also outlined each sector where greenhouse gases are emitted. You can read more about those sectors and sources for gases in our guide on solutions to climate change.


Effects Of Climate Change

What is important to note is that there are already some effects that have taken place (such as the rise in temperature, shrinking ice etc.

But, future effects can only be forecasted – but not guaranteed.


Climate change affects the world as a whole, but can also affect different countries, and regions within those countries differently.

There are environmental, social and economic effects.

Some of the current and future effects of climate change are…

  • Warming oceans
  • Shrinking ice sheets
  • Glacial retreat
  • Decreased snow cover
  • Sea level rise
  • Declining Arctic sea ice
  • Extreme events
  • Ocean acidification [due to increased carbon levels]



Global warming and a changing climate have a range of potential ecological, physical and health impacts, including extreme weather events (such as floods, droughts, storms, and heatwaves); sea-level rise; altered crop growth; and disrupted water systems.



  • The enhanced greenhouse effect is expected to change many of the basic weather patterns that make up our climate, including wind and rainfall patterns and the incidence and intensity of storms.
  • Every aspect of our lives is in some way influenced by the climate. For example, we depend on water supplies that exist only under certain climatic conditions, and our agriculture requires particular ranges of temperature and rainfall.



  • Ice is melting in both polar ice caps and mountain glaciers. Lakes around the world, including Lake Superior, are warming rapidly — in some cases faster than the surrounding environment. Animals are changing migration patterns and plants are changing the dates of activity, such as trees budding their leaves earlier in the spring and dropping them later in the fall.
  • There’s an increase in average temperatures and the temperature extremes, there’s extreme weather events, there’s ice melt, there’s sea level rise and acidification, plants and animals are affected, and there are social consequences relating to agriculture, food security and health implication just to name a few.



  • Global effects – hotter days, rising sea levels, more frequent and intense extreme weather events, oceans are warming and acidifying. As humans, every aspect of our life is reliant on the natural environment. This includes the food we eat, the air we breathe, the water we drink, the clothes we wear and the products that are made and sold to create jobs and drive the economy. We need a healthy and stable climate for these things.
  • Country Specific effects such as Australia – temperature rises, water shortages, increased fire threats, drought, weed and pest invasions, intense storm damage and salt invasion.
  • Threatening of the Great Barrier Reef.
  • Animals and plants – One in six species is at risk of extinction because of climate change and habitat destruction and environmental change.
  • Food and Farming – Changes to rainfall patterns, increasingly severe drought, more frequent heat waves, flooding and extreme weather make it more difficult for farmers to graze livestock and grow produce, reducing food availability and making it more expensive to buy.
  • Water – Reduced rainfall and increasingly severe droughts may lead to water shortages.
  • Coastal erosion – Rising sea levels and more frequent and intense storm surges will see more erosion of Australia’s coastline, wearing away and inundating community and residential properties.
  • Health – Increasingly severe and frequent heat waves may lead to death and illness, especially among the elderly. Higher temperatures and humidity could also produce more mosquito-borne disease.
  • Damage to homes – Increasingly severe extreme weather events like bushfires, storms, floods, cyclones and coastal erosion, will see increased damage to homes, as well as more costly insurance premiums.
  • Coral bleaching – Rising temperatures and acidity within our oceans is contributing to extreme coral bleaching events, like the 2016 event that destroyed more than one-third of the Great Barrier Reef.
  • Overall – Within Australia, the effects of global warming vary from region to region.
    The impacts of global warming are already being felt across all areas of Australian life, and these will continue to worsen if we do not act now to limit global warming to 1.5°C.



Future effects might be:

Global climate change has already had observable effects on the environment. Glaciers have shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and trees are flowering sooner.

Scientists have high confidence that global temperatures will continue to rise for decades to come, largely due to greenhouse gases produced by human activities. The Intergovernmental Panel on Climate Change (IPCC), which includes more than 1,300 scientists from the United States and other countries, forecasts a temperature rise of 2.5 to 10 degrees Fahrenheit over the next century.

According to the IPCC, the extent of climate change effects on individual regions will vary over time and with the ability of different societal and environmental systems to mitigate or adapt to change.

The IPCC predicts that increases in global mean temperature of less than 1.8 to 5.4 degrees Fahrenheit (1 to 3 degrees Celsius) above 1990 levels will produce beneficial impacts in some regions and harmful ones in others. Net annual costs will increase over time as global temperatures increase.

“Taken as a whole,” the IPCC states, “the range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time.”

According to the Third and Fourth National Climate Assessment Reports, future effects will be…

  • change through this century and beyond depending on how many greenhouse gases we emit and how sensitive our climate is to them
  • temperatures will continue to rise
  • Frost free season and growing season will lengthen
  • There will be changes in precipitation patterns
  • There will be more droughts and heat waves
  • Hurricanes will become stronger and more intense
  • Sea levels will rise between 1-4 feet by 2100
  • The Arctic is likely to become ice free

NASA also outline the US regional effects so far in Northeast, Northwest, Southeast, Midwest and Southwest. For example, in the Southwest – increased heat, drought and insect outbreaks, all linked to climate change, have increased wildfires. Declining water supplies, reduced agricultural yields, health impacts in cities due to heat, and flooding and erosion in coastal areas are additional concerns.



Evidence That Climate Change Is A Real Issue, & Is A Direct Cause Of Other Problems

In summary, the main points of evidence are:

  • it has been proved how much of a warming effect greenhouse gases like carbon dioxide have on the earth
  • there was a sharp rise in carbon dioxide levels (in parts per million) since the industrial revolution in the 19th century, and in particular since 1950 – most of it from human activity
  • there was rise in average global earth surface (air) temperature in the same time – compared to pre 1950’s levels
  • there has been a change in other events and things in the same time such as sea levels, ice melting, etc. – compared to pre 1950’s levels


So, you have to be able to prove:

  • Greenhouse gases warm the earth and it’s climate
  • Humans are emitting greenhouse gases at certain levels
  • The GHG’s that human are emitting are causing the warming (as opposed to natural emissions causing it)
  • There are negative side effects of this warming (e.g. sea level rise, ice melt etc.)
  • That this warming and these negative side effects wouldn’t be happening, or happening to the extent they are now without the human caused greenhouse gas emissions (essentially comparing what is happening now with excess emissions, to a baseline without these heavy emissions)
  • Some further information explaining this and evidence is…
  • The finding that the climate has warmed in recent decades and that human activities are producing global climate change has been endorsed by every national science academy that has issued a statement on climate change, including the science academies of all of the major industrialized countries.
  • Scientific consensus is normally achieved through communication at conferences, publication in the scientific literature, replication (reproducible results by others), and peer review. In the case of global warming, many governmental reports, the media in many countries, and environmental groups, have stated that there is virtually unanimous scientific agreement that human-caused global warming is real and poses a serious concern.
  • Several studies of the consensus have been undertaken. Among the most-cited is a 2013 study of nearly 12,000 abstracts of peer-reviewed papers on climate science published since 1990, of which just over 4,000 papers expressed an opinion on the cause of recent global warming. Of these, 97% agree, explicitly or implicitly, that global warming is happening and is human-caused. It is “extremely likely” that this warming arises from “… human activities, especially emissions of greenhouse gases …” in the atmosphere. Natural change alone would have had a slight cooling effect rather than a warming effect.



  • [the current warming trend] is extremely likely (greater than 95 percent probability) to be the result of human activity since the mid-20th century and proceeding at a rate that is unprecedented over decades to millennia.

– IPCC Fifth Assessment Report via


  • For 400,000 years, carbon dioxide levels have never been above 280 to 300 parts per million
  • During ice ages, COlevels were around 200 parts per million (ppm), and during the warmer interglacial periods, they hovered around 280 ppm
  • Around 1950, carbon dioxide levels surpassed 300 parts per million, and as of 2013, levels surpassed 400 parts per million
  • This rise in carbon closely mimics our burning of fossil fuels in the same time. What we know about fossil fuels is that they emit carbon dioxide, and 60 percent of fossil-fuel emissions stay in the air.
  • If fossil-fuel burning continues at a business-as-usual rate, such that humanity exhausts the reserves over the next few centuries, CO2 will continue to rise to levels of order of 1500 ppm. The atmosphere would then not return to pre-industrial levels even tens of thousands of years into the future.



  • The Earth’s climate has changed throughout history. Just in the last 650,000 years there have been seven cycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago marking the beginning of the modern climate era — and of human civilization. Most of these climate changes are attributed to very small variations in Earth’s orbit that change the amount of solar energy our planet receives.
  • The current warming trend is of particular significance because most of it is extremely likely (greater than 95 percent probability) to be the result of human activity since the mid-20th century and proceeding at a rate that is unprecedented over decades to millennia.
  • Earth-orbiting satellites and other technological advances have enabled scientists to see the big picture, collecting many different types of information about our planet and its climate on a global scale. This body of data, collected over many years, reveals the signals of a changing climate.
  • The heat-trapping nature of carbon dioxide and other gases was demonstrated in the mid-19th century.Their ability to affect the transfer of infrared energy through the atmosphere is the scientific basis of many instruments flown by NASA. There is no question that increased levels of greenhouse gases must cause the Earth to warm in response.
  • Ice cores drawn from Greenland, Antarctica, and tropical mountain glaciers show that the Earth’s climate responds to changes in greenhouse gas levels. Ancient evidence can also be found in tree rings, ocean sediments, coral reefs, and layers of sedimentary rocks. This ancient, or paleoclimate, evidence reveals that current warming is occurring roughly ten times faster than the average rate of ice-age-recovery warming.
  • Further to this, there are these events tied to the above:
  • Global temperature rise – The planet’s average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere. Most of the warming occurred in the past 35 years, with the five warmest years on record taking place since 2010. Not only was 2016 the warmest year on record, but eight of the 12 months that make up the year — from January through September, with the exception of June — were the warmest on record for those respective months.
  • Warming Oceans – The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of 0.302 degrees Fahrenheit since 1969.
  • Shrinking Ice Sheets – The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA’s Gravity Recovery and Climate Experiment show Greenland lost an average of 281 billion tons of ice per year between 1993 and 2016, while Antarctica lost about 119 billion tons during the same time period. The rate of Antarctica ice mass loss has tripled in the last decade.
  • Glacial Retreat – Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.
  • Decreased Snow Cover – Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and that the snow is melting earlier.
  • Sea Level Rise – Global sea level rose about 8 inches in the last century. The rate in the last two decades, however, is nearly double that of the last century.
  • Declining Arctic Sea Ice – Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades.
  • Extreme Events – The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. The U.S. has also witnessed increasing numbers of intense rainfall events.
  • Ocean Acidification – Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent. This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year.



  • Look at how the world has warmed since the Industrial Revolution.
  • We see that over the last few decades, temperatures have risen sharply at the global level — to approximately 0.8 degrees celsius higher than our 1961-1990 baseline.
  • When extended back to 1850, we see that temperatures then were a further 0.4 degrees colder than they were in our 1961-1990 baseline.
  • Overall, if we look at the total temperature increase since pre-industrial times, this therefore amounts to approximately 1.2 degrees celcius. We have now surpassed the one-degree mark, an important marker as it brings us more than halfway to the global limit of keeping warming below two degrees celsius.
  • It’s also important to look at trends by hemisphere (North and South), as well as the tropics (defined as 30 degrees above and below the equator).
  • Here we see that the median temperature increase in the North Hemisphere is higher, at closer to 1.4 degrees celcius since 1850, and less in the Southern Hemisphere (closer to 0.8 degrees celcius). Evidence suggests that this distribution is strongly related to ocean circulation patterns (notably the North Atlantic Oscillation) which has resulted in greater warming in the northern hemisphere.



  • Climate change is happening
  • Tens of thousands of scientists in more than a hundred nations have amassed an overwhelming amount of evidence that humans are the cause
  • We are statistically more confident that humans cause climate change than that smoking causes cancer
  • There are nine main independently studied, but physically related, lines of evidence
  • (it is really the first seven that, combined, point to human activities as the only explanation of rising global temperatures since the Industrial Revolution, and the subsequent climate changes (such as ice melt and sea level rise) that have occurred due to this global warming.)
  • Those nine lines of evidence are:
  1. Simple chemistry – when we burn carbon-based materials, carbon dioxide (CO2) is emitted (research beginning in 1900s)
  2. Basic accounting of what we burn, and therefore how much CO2 we emit (data collection beginning in 1970s)
  3. Measuring CO2 in the atmosphere and trapped in ice to find that it is increasing and that the levels are higher than anything we’ve seen in hundreds of thousands of years (measurements beginning in 1950s)
  4. Chemical analysis of the atmospheric CO2 that reveals the increase is coming from burning fossil fuels (research beginning in 1950s)
  5. Basic physics that shows us that CO2 absorbs heat (research beginning in 1820s)
  6. Monitoring climate conditions to find that recent warming of the Earth is correlated to and follows rising CO2 emissions (research beginning in 1930s)
  7. Ruling out natural factors that can influence climate like the sun and ocean cycles (research beginning in 1830s)
  8. Employing computer models to run experiments of natural versus human-influenced simulations of Earth (research beginning in 1960s)
  9. Consensus among scientists who consider all previous lines of evidence and make their own conclusions (polling beginning in 1990s)



  • CO2 keeps the Earth warmer than it would be without it. Humans are adding CO2 to the atmosphere, mainly by burning fossil fuels. And there is empirical evidence that the rising temperatures are being caused by the increased CO2.
  • The reason that the Earth is warm enough to sustain life is because of greenhouse gases in the atmosphere. These gases act like a blanket, keeping the Earth warm by preventing some of the sun’s energy being re-radiated into space. The effect is exactly the same as wrapping yourself in a blanket – it reduces heat loss from your body and keeps you warm. If we add more greenhouse gases to the atmosphere, the effect is like wrapping yourself in a thicker blanket: even less heat is lost.
  • So how can we tell what effect CO2 is having on temperatures, and if the increase in atmospheric CO2 is really making the planet warmer?
  • One way of measuring the effect of CO2 is by using satellites to compare how much energy is arriving from the sun, and how much is leaving the Earth. What scientists have seen over the last few decades is a gradual decrease in the amount of energy being re-radiated back into space. In the same period, the amount of energy arriving from the sun has not changed very much at all. This is the first piece of evidencemore energy is remaining in the atmosphere.
  • The primary greenhouse gases – carbon dioxide (CO2), methane (CH4), water vapour, nitrous oxide and ozone – comprise around 1% of the air. This tiny amount has a very powerful effect, keeping the planet 33°C (59.4°F) warmer than it would be without them. (The main components of the atmosphere – nitrogen and oxygen – are not greenhouse gases, because they are virtually unaffected by long-wave, or infrared, radiation). This is the second piece of evidencea provable mechanism by which energy can be trapped in the atmosphere
  • We now look at the amount of CO2 in the air. We know from bubbles of air trapped in ice cores that before the industrial revolution, the amount of CO2 in the air was approximately 280 parts per million (ppm). In June 2013, the NOAA Earth System Research Laboratory in Hawaii announced that, for the first time in thousands of years, the amount of CO2 in the air had gone up to 400ppm. That information gives us the next piece of evidenceCO2 has increased by nearly 43% in the last 150 years.
  • The final piece of evidence is ‘the smoking gun’, the proof that CO2 is causing the increases in temperature. CO2 traps energy at very specific wavelengths, while other greenhouse gases trap different wavelengths.  In physics, these wavelengths can be measured using a technique called spectroscopy. When looking at the different wavelengths of energy, measured at the Earth’s surface, on a Spectroscopy Graph – among the spikes you can see energy being radiated back to Earth by ozone (O3), methane (CH4), and nitrous oxide (N20). But the spike for CO2 dwarfs all the other greenhouse gases, and tells us something very important: most of the energy being trapped in the atmosphere corresponds exactly to the wavelength of energy captured by CO2.
  • To sum up:
  • 1. What is happening – More energy is remaining in the atmosphere on Earth
  • 2. How is this happening – Greenhouse gases are the mechanism by which energy is trapped in the atmosphere
  • 3. Why is this happening – CO2 has increased by nearly 50% in the last 150 years and the increase is from burning fossil fuels
  • 4. Linking the tw0 – energy being trapped in the atmosphere corresponds exactly to the wavelengths of energy captured by CO2
  • This is empirical evidence that proves, step by step, that man-made carbon dioxide is causing the Earth to warm up.



  • The science on the human contribution to modern warming is quite clear. Humans emissions and activities have caused around 100% of the warming observed since 1950
  • Since 1850, almost all the long-term warming can be explained by greenhouse gas emissions and other human activities.
  • If greenhouse gas emissions alone were warming the planet, we would expect to see about a third more warming than has actually occurred. They are offset by cooling from human-produced atmospheric aerosols.
  • Aerosols are projected to decline significantly by 2100, bringing total warming from all factors closer to warming from greenhouse gases alone.
  • Natural variability in the Earth’s climate is unlikely to play a major role in long-term warming.
  • Some of the findings that back up these results are…
  • Greenhouse gas forcings match actual observed global surface temperature warming – Scientists measure the various factors that affect the amount of energy that reaches and remains in the Earth’s climate. They are known as “radiative forcings”. They can be natural (such as volcanoes) and man made (such as greenhouse gases). When looking at a graph that shows the estimated role of each different climate forcing in changing global surface temperatures since records began in 1850, of all the radiative forcings analysed, only increases in greenhouse gas emissions produce the magnitude of warming experienced over the past 150 years.
  • Human forcings match actual observed global surface temperature warmings
  • Land temperatures are rising faster now – Land temperatures have warmed considerably faster than average global temperatures over the past century, with temperatures reaching around 1.7C above pre-industrial levels in recent years.
  • From the models, future forecasts are that land warms by around 4C by 2100 compared to 3C globally for surface temperature
  • While human factors explain all the long-term warming, there are some specific periods that appear to have warmed or cooled faster than can be explained based on our best estimates of radiative forcing.
  • Short term warming or cooling may occur via natural factors, but long term natural variability to impact long-term warming trends is extremely unlikely
  • Internal variability is likely to have a much larger role in regional temperatures. For example, in producing unusually warm periods in the Arctic and the US in the 1930s.
  • In summary – While there are natural factors that affect the Earth’s climate, the combined influence of volcanoes and changes in solar activity would have resulted in cooling rather than warming over the past 50 years. The global warming witnessed over the past 150 years matches nearly perfectly what is expected from greenhouse gas emissions and other human activity, both in the simple model examined here and in more complex climate models. The best estimate of the human contribution to modern warming is around 100% . Some uncertainty remains due to the role of natural variability, but researchers suggest that ocean fluctuations and similar factors are unlikely to be the cause of more than a small fraction of modern global warming.

– answers many climate change related questions that give evidence of the link between greenhouse gases and climate change at

These questions and answers include:

    • Is the climate warming (lists the range of observations, indications and evidence that show warming has occured)
    • How do scientists know that recent climate change is largely caused by human activities?
    • CO2 is already in the atmosphere naturally, so why are emissions from human activity significant?
    • What role has the Sun played in climate change in recent decades?
    • What do changes in the vertical structure of atmospheric temperature – from the surface up to the stratosphere – tell us about the causes of recent climate change?
    • Climate is always changing. Why is climate change of concern now?
    • Is the current level of atmospheric CO2concentration unprecedented in Earth’s history?
    • Is there a point at which adding more CO2 will not cause further warming?
    • Does the rate of warming vary from one decade to another?
    • Does the recent slowdown of warming mean that climate change is no longer happening?
    • If the world is warming, why are some winters and summers still very cold?
    • Why is Arctic sea ice reducing while Antarctic sea ice is not?
    • How does climate change affect the strength and frequency of floods, droughts, hurricanes and tornadoes?
    • How fast is sea level rising?
    • What is ocean acidification and why does it matter?
    • How confident are scientists that Earth will warm further over the coming century?
    • Are climate changes of a few degrees a cause for concern?
    • What are scientists doing to address key uncertainties in our understanding of the climate system?
      • Are disaster scenarios about tipping points like ‘turning off the Gulf Stream’ and release of methane from the Arctic a cause for concern?
    • If emissions of greenhouse gases were stopped, would the climate return to the conditions of 200 years ago?



Climate Change Evidence Stats

C02 & Other Greenhouse Gas Level Changes

The global mean CO2 level in 2013 was 395 parts per million. This concentration represents a 43 per cent increase from pre-industrial levels; it is likely to be at the highest concentration in at least 2 million years.

Methane and nitrous oxide concentrations, mostly from agriculture, have increased by 150% and 20% respectively since 1750.



Records of air bubbles in ancient Antarctic ice show us that carbon dioxide and other greenhouse gases are now at their highest concentrations for more than 800,000 years.



Global Surface Temperature Change

We have tracked significant increase in global temperatures of at least 0.85°C and a sea level rise of 20cm over the past century.



You can check out global temperature change at 


Global Sea Level Change

We have tracked significant increase in global temperatures of at least 0.85°C and a sea level rise of 20cm over the past century.



You can check out global sea level at 


Average Sea Surface Temperature Change

You can check out average sea surface temperature which is rising at


Looking At Evidence Overall

Overall, you can’t just look at temperature (air temperature, land temperature, water temperature) to diagnose or assess climate change. You also have to look at sea levels, ocean acidity, ice sheets, ecosystem trends, and other factors to get a well rounded answer.


Ways To Monitor The Impact Climate Change Is Having Now & Into The Future

Some of the long-term effects of global climate change in the United States are listed in the Third and Fourth National Climate Assessment Reports.

But, NASA list some of the effects and expected effects of climate change at

(Some effects that scientists had predicted in the past would result from global climate change are now occurring: loss of sea ice, accelerated sea level rise and longer, more intense heat waves.)

Among the impacts to look out for and monitor and link to each other are:

  • Continued C02 parts per million levels rising
  • Continued earth air surface temperature rising
  • Land temperature rising
  • Ocean temperatures rising
  • Glaciers shrinking
  • Ice on rivers and lakes breaking up earlier
  • Plant and animal ranges shifting
  • Trees and plants flowering sooner
  • Loss of sea ice
  • Accelerated sea level rise
  • Longer, more intense heat waves
  • Frost free and growing seasons lengthening (The largest increases in the frost-free season (more than eight weeks) are projected for the western U.S., particularly in high elevation and coastal areas.)
  • Changes in precipitation patterns – trend towards increased heavy precipitation events
  • More droughts, heat waves and hot days (By the end of this century, what have been once-in-20-year extreme heat days (one-day events) are projected to occur every two or three years over most of the nation.)
  • Cold waves to become less intense
  • Hurricanes becoming stronger and more intense (The intensity, frequency and duration of North Atlantic hurricanes, as well as the frequency of the strongest (Category 4 and 5) hurricanes, have all increased since the early 1980s. The relative contributions of human and natural causes to these increases are still uncertain)
  • Sea levels to rise (Global sea level has risen by about 8 inches since reliable record keeping began in 1880. It is projected to rise another 1 to 4 feet by 2100. This is the result of added water from melting land ice and the expansion of seawater as it warms.)
  • Land subsidence to increase (land sinking)
  • Flooding of coastal and sea side land to increase
  • Arctic Ocean to become ice free
  • Infrastructure, agriculture, fisheries and ecosystems will be increasingly compromised
  • Increasing wildfire, insect outbreaks and tree diseases
  • Increasing ocean acidity
  • Decreased freshwater availability
  • Increased erosion



Debate & Disagreement Over Climate Change & Global Warming

You can read more about the debate and controversy over climate change and it’s impact/effects at 


Answers To Skeptical Arguments Against Climate Change

Skeptical Science has a good resource answering common skeptical arguments against climate change:



How Are C02 Concentrations Obtained In Current Time, & From The Past?

More recently, there are observatories that measure air CO2 levels.

But, historic CO2 levels can be found in ice cores, and also rock sediment samples from the ocean and lakes.

There are other ancient samples (such as tree rings, studying ancient organisms etc.) that can also be used to get an idea of CO2 levels from the past.

Read more about how climate change indicators and past CO2 levels are measured in this guide.


Climate Change & Trade/Import Between Developed vs Developing Countries

  • Climate change can lead to lead to widespread drought, disease and desperation in some of the world’s poorest regions
  • Migration by refugees affected by climate change is predicted in the future
  • Richer nations have a lot of carbon emissions contained in the products and materials they import from developing countries
  • Of the carbon emissions that European consumers are personally responsible for, around 22% are allocated elsewhere under conventional carbon accounting practices. For consumers in the US, the figure is around 15%.
  • Heavy industry and the constant demand for consumer goods are key contributors to climate change
  • 30% of global greenhouse gas emissions are produced through the process of converting metal ores and fossil fuels into the cars, washing machines and electronic devices that help prop up richer economies
  • Richer nations have more purchasing power and through their consumption of products, contribute to emissions and pollution
  • For every item bought or sold there is a rise in GDP, and with each 1% increase in GDP there is a corresponding 0.5 to 0.7% rise in carbon emissions
  • For metal ores alone, the extraction rate more than doubled between 1980 and 2008
  • Every time you buy a new car, for instance, you effectively mine 3-7g of “platinum group metals” to coat the catalytic converter. The six elements in the platinum group have the greatest environmental impact of all metals, and producing just one kilo requires the emission of thousands of kilos of CO₂
  • This is only one example of the toll poorer countries are taking to satisfy richer countries
  • The problem is that in poorer countries choose to accept this behavior for a variety of factors, and citizens see it as the only way to get out of poverty (because it provides jobs)
  • Richer nations must start implementing sustainable material strategies that address a product’s entire lifecycle from mining to manufacturing, use, and eventually to disposal. They must consider the well being of the people and environment in the countries they are importing from
  • Consumers can also vote with their dollars and buy from more ethical and sustainable countries



Potential Climate Change Solutions (Mitigation, Adaptation, Carbon Sequestering)

The best solution is to bring emissions to zero as soon as possible.

But, realistically – there is going to need to be a different approach to doing that in each industry and sector of society.

Two big examples are – renewable energy sources in the electricity generation sector, and cleaner cars in the transport sector.

There needs to be an approach that considers employment, the economy and practicality right now, and the future environmental needs of the future.

Building infrastructure, getting funding, transferring to new technologies and power sources – all take time and have technical challenges – so it’s something that requires serious planning and research as to how to best do it.


Some specific solutions might include:

  • More efficient use of residential electronics, and new technology for household electronics
  • More efficient use of residential appliances
  • Retrofit residential HVAC
  • Tillage and residue management
  • Insulation retrofits for residential
  • Hybrid cars
  • Waste recycling
  • Lighting – switch from incandescent to LED lights (residential)
  • Retrofit insulation (commercial)
  • Better motor systems efficiency
  • Cropland nutrient management
  • Clinker substitution by fly ash
  • Electricity from landfill gas
  • Efficiency improvements by different industries
  • Rice management
  • 1st generation biofuels
  • Small hydro
  • Reduced slash and burn agriculture conversion
  • Reduced pastureland conversion
  • Grassland management
  • Geothermal energy
  • Organic soil restoration
  • Building energy efficiency in new builds
  • 2nd gen biofuels
  • Degraded land restoration
  • Pastureland afforestation
  • Nuclear energy
  • Degraded forest reforestation
  • Low penetration wind technology and energy
  • Solar CSP technology and energy
  • Solar PV technology and energy
  • High penetration wind technology and energy
  • Reduced intensive agriculture conversion
  • Power plant biomass co-firing
  • Coal CCS new build
  • Iron and steel CCS new build
  • Coal CCS retrofit
  • Gas plant CCS retrofit



Also according to

  • To keep global temperature rise below the agreed 2°C, global carbon emission must peak in the next decade and from 2070 onward must be negative
  • The goal, with the Paris Agreement in mind, is limiting warming to 2℃ above pre-industrial levels. The Paris Agreement went further, aiming to “pursue efforts” towards a more ambitious goal of just 1.5℃. Given we’re already at around 1℃ of warming, that’s a relatively short-term goal.
  • The warming will slow to a potentially manageable pace only when human emissions are reduced to zero. The good news is that they are now falling in many countries as a result of programs like fuel-economy standards for cars, stricter building codes and emissions limits for power plants. But experts say the energy transition needs to speed up drastically to head off the worst effects of climate change
  • The energy sources with the lowest emissions include wind turbines, solar panels, hydroelectric dams and nuclear power stations. Power plants burning natural gas also produce fewer emissions than those burning coal. Using renewables can be costlier in the short term
  • Burning gas instead of coal in power plants reduces emissions in the short run, though gas is still a fossil fuel and will have to be phased out in the long run
  • “Clean coal” is an approach in which the emissions from coal-burning power plants would be captured and pumped underground. It has yet to be proven to work economically, but some experts think it could eventually play a major role.



Mitigation of climate change are actions to reduce greenhouse gas emissions, or enhance the capacity of carbon sinks to absorb greenhouse gases from the atmosphere.

There is a large potential for future reductions in emissions by a combination of activities, including energy conservation and increased energy efficiency; the use of low-carbon energy technologies, such as renewable energy, nuclear energy, and carbon capture and storage; and enhancing carbon sinks through, for example, reforestation and preventing deforestation.

A 2015 report by Citibank concluded that transitioning to a low carbon economy would yield positive return on investments.

Apart from mitigation, adaptation and climate engineering are other options for responses.



Cost Of Pursuing Climate Change Mitigation

According to OurWorldInData, these are very loose and very roughly estimated costs to pursue climate change mitigation. These costs have lots of variables:

The possible cost-benefit of taking global and regional action on climate change is often a major influencing factor on the effectiveness of mitigation agreements and measures.

If we aggressively pursue all of the low-cost abatement opportunities currently available, the total global economic cost would be €200-350 billion per year by 2030. This is less than one percent of the forecasted global GDP in 2030.

If we include these additional opportunities, our maximum technical abatement potential by 2030 totals 47 billion tonnes of CO2e per year. Our maximum global potential is therefore a 65-70% reduction relative to our current projected pathway.



Recent Greenhouse Gas Trends (Total Greenhouse Gas Emissions)

Since 1990, gross U.S. greenhouse gas emissions have increased by about 2 percent. From year to year, emissions can rise and fall due to changes in the economy, the price of fuel, and other factors.

In 2016, U.S. greenhouse gas emissions decreased compared to 2015 levels. This decrease was largely driven by a decrease in emissions from fossil fuel combustion, which was a result of multiple factors including substitution from coal to natural gas consumption in the electric power sector; warmer winter conditions that reduced demand for heating fuel in the residential and commercial sectors.

You can see total US GHG emissions between 1990 and 2016 at



EPA also shows the total global and national GG emissions by %:

  • National –
  • Global –

In the US you can see carbon dioxide emissions have been gradually decreasing since around 2007 to 2016.


Forecast For Climate Change Into The Future

Climate change and it’s effects can be forecasted into the future, but not with an absolute guarantee (some forecasts from the past weren’t completely accurate).

There variables that can impact how quickly warming takes place, and how the earth and different indicators in different parts of the world react.

Climate models can forecast for 100’s of different scenarios based on these variables.

There may be warming in some parts of the world, and there may be cooling in others just as one example.

It’s more realistic to be aware of the indicators and causes, understand what potential future scenarios might be, and continue to monitor them and adjust expectations accordingly.

What most experts do agree on though is that it’s in our best interests to decrease human GHG emissions as soon as possible.



  • The continued burning of fossil fuels will inevitably lead to further climate warming. The complexity of the climate system is such that the extent of this warming is difficult to predict, particularly as the largest unknown is how much greenhouse gas we keep emitting.
  • The IPCC has developed a range of emissions scenarios or Representative Concentration Pathways (RCPs) to examine the possible range of future climate change.
  • Using scenarios ranging from business-as-usual to strong longer-term managed decline in emissions, the climate model projections suggest the global mean surface temperature could rise by between 2.8°C and 5.4°C by the end of the 21st century. Even if all the current country pledges submitted to the Paris conference are achieved we would still only just be at the bottom end of this range.
  • The sea level is projected to rise by between 52cm and 98cm by 2100, threatening coastal cities, low-lying deltas and small island nations. Snow cover and sea ice are projected to continue to reduce, and some models suggest that the Arctic could be ice-free in late summer by the latter part of the 21st century.
  • Heat waves, droughts, extreme rain and flash flood risks are projected to increase, threatening ecosystems and human settlements, health and security. One major worry is that increased heat and humidity could make physical work outside impossible.
  • Changes in precipitation are also expected to vary from place to place. In the high-latitude regions (central and northern regions of Europe, Asia and North America) the year-round average precipitation is projected to increase, while in most sub-tropical land regions it is projected to decrease by as much as 20%, increasing the risk of drought.
  • In many other parts of the world, species and ecosystems may experience climatic conditions at the limits of their optimal or tolerable ranges or beyond.
  • Human land use conversion for food, fuel, fibre and fodder, combined with targeted hunting and harvesting, has resulted in species extinctions some 100 to 1000 times higher than background rates. Climate change will only speed things up.
  • This is the challenge our world leaders face. To keep global temperature rise below the agreed 2°C, global carbon emission must peak in the next decade and from 2070 onward must be negative: we must start sucking out carbon dioxide from the atmosphere.
  • Despite 30 years of climate change negotiations there has been no deviation in greenhouse gas emissions from the business-as-usual pathway, so many feel keeping global warming to less than 2°C will prove impossible.
  • Previous failures, most notably at Copenhagen in 2009, set back meaningful global cuts in emissions by at least a decade. Paris, however, offers a glimmer of hope.



  • Near- and long-term trends in the global energy system are inconsistent with limiting global warming at below 1.5 or 2 °C, relative to pre-industrial levels. Pledges made as part of the Cancún agreements are broadly consistent with having a likely chance (66 to 100% probability) of limiting global warming (in the 21st century) at below 3 °C, relative to pre-industrial levels.



What does the future of our carbon dioxide and greenhouse gas emissions look like? [here are] … a range of potential future scenarios of global greenhouse gas emissions (measured in gigatonnes of carbon dioxide equivalents), based on data from Climate Action Tracker. Here, five scenarios are shown:

  • No climate policies: projected future emissions if no climate policies were implemented; this would result in an estimated 4.1-4.8°C warming by 2100 (relative to pre-industrial temperatures)
  • Current climate policies: projected warming of 3.1-3.7°C by 2100 based on current implemented climate policies
  • National pledges: if all countries achieve their current targets/pledges set within the Paris climate agreement, it’s estimated average warming by 2100 will be 2.6-3.2°C. This will go well beyond the overall target of the Paris Agreement to keep warming “well below 2°C”.
  • 2°C consistent: there are a range of emissions pathways that would be compatible with limiting average warming to 2°C by 2100. This would require a significant increase in ambition of the current pledges within the Paris Agreement.
  • 1.5°C consistent: there are a range of emissions pathways that would be compatible with limiting average warming to 1.5°C by 2100. However, all would require a very urgent and rapid reduction in global greenhouse gas emissions.



Climate Change Overall Is A Complex Process – It Has Drivers, Amplifiers, Diminishers & Feedbacks That All Interact With Each Other

Based just on the physics of the amount of energy that CO2 absorbs and emits, a doubling of atmospheric CO2 concentration from pre-industrial levels (up to about 560 ppm) would, by itself, cause a global average temperature increase of about 1 °C (1.8 °F).

In the overall climate system, however, things are more complex; warming leads to further effects (feedbacks) that either amplify or diminish the initial warming.

The most important feedbacks involve various forms of water.

A warmer atmosphere generally contains more water vapour.

Water vapour is a potent greenhouse gas, thus causing more warming; its short lifetime in the atmosphere keeps its increase largely in step with warming. Thus, water vapour is treated as an amplifier, and not a driver, of climate change.

Higher temperatures in the polar regions melt sea ice and reduce seasonal snow cover, exposing a darker ocean and land surface that can absorb more heat, causing further warming.

Another important but uncertain feedback concerns changes in clouds. Warming and increases in water vapour together may cause cloud cover to increase or decrease which can either amplify or dampen temperature change depending on the changes in the horizontal extent, altitude, and properties of clouds.

The latest assessment of the science indicates that the overall net global effect of cloud changes is likely to be to amplify warming.

The ocean moderates climate change. The ocean is a huge heat reservoir, but it is difficult to heat its full depth because warm water tends to stay near the surface. The rate at which heat is transferred to the deep ocean is therefore slow; it varies from year to year and from decade to decade, and helps to determine the pace of warming at the surface.

Observations of the sub-surface ocean are limited prior to about 1970, but since then, warming of the upper 700 m (2,300 feet) is readily apparent. There is also evidence of deeper warming.

Surface temperatures and rainfall in most regions vary greatly from the global average because of geographical location, in particular latitude and continental position.

Both the average values of temperature, rainfall, and their extremes (which generally have the largest impacts on natural systems and human infrastructure), are also strongly affected by local patterns of winds.

Estimating the effects of feedback processes, the pace of the warming, and regional climate change requires the use of mathematical models of the atmosphere, ocean, land, and ice (the cryosphere) built upon established laws of physics and the latest understanding of the physical, chemical and biological processes affecting climate, and run on powerful computers.

Models vary in their projections of how much additional warming to expect (depending on the type of model and on assumptions used in simulating certain climate processes, particularly cloud formation and ocean mixing), but all such models agree that the overall net effect of feedbacks is to amplify warming.



Other Notes & Stats On Climate Change, C02 & Greenhouse Emissions

C02 and Economic development

Historically, CO2 emissions have been primarily driven by increasing fuel consumption. This energy driver has been, and continues to be, a fundamental pillar of economic growth and poverty alleviation. As a result, there is a strong correlation between per capita CO2 emissions and GDP per capita for countries.

There are also noticeable within-country inequalities in greenhouse gas emissions



C02 and Poverty alleviation

The link between economic growth and CO2 described above raises an important question: do we actually want the emissions of low-income countries to grow despite trying to reduce global emissions? In our historical and current energy system (which has been primarily built on fossil fuels), CO2 emissions have been an almost unavoidable consequence of the energy access necessary for development and poverty alleviation.

In general, we see a very similar correlation in both CO2 and energy: higher emissions and energy access are correlated to lower levels of extreme poverty. Energy access is therefore an essential component in improved living standards and poverty alleviation.

In an ideal world, this energy could be provided through 100% renewable energy: in such a world, CO2emissions could be an avoidable consequence of development. However, currently we would expect that some of this energy access will have to come from fossil fuel consumption (although potentially with a higher mix of renewables than older industrial economies). Therefore, although the global challenge is to reduce emissions, some growth in per capita emissions from the world’s poorest countries remains a sign of progress in terms of changing living conditions and poverty alleviation.



C02 Intensity Of Economies 

If economic growth is historically linked to growing CO2 emissions, why do countries have differing levels of per capita CO2 emissions despite having similar GDP per capita levels? These differences are captured by the differences in the CO2 intensity of economies; CO2 intensity measures the amount of CO2 emitted per unit of GDP (kgCO2 per int-$). There are two key variables which can affect the CO2 intensity of an economy:

  • Energy efficiency: the amount of energy needed for one unit of GDP output. This is often related to productivity and technology efficiency, but can also be related to the type of economic activity underpinning output. If a country’s economy transitions from manufacturing to service-based output, less energy is needed in production, therefore less energy is used per unit of GDP.
  • Carbon efficiency: the amount of CO2 emitted per unit energy (grams of CO2 emitted per kilowatt-hour). This is largely related to a country’s energy mix. An economy powered by coal-fired energy will produce higher CO2 emissions per unit of energy versus an energy system with a high percentage of renewable energy. As economies increase their share of renewable capacity, efficiency improves and the amount of CO2 emitted per unit energy falls.

Global CO2 intensity has been steadily falling since 1990.17 This is likely thanks to both improved energy and technology efficiency, and increases in the capacity of renewables. The carbon intensity of nearly all national economies has also fallen in recent decades. Today, we see the highest intensities in Asia, Eastern Europe, and South Africa. This is likely to be a compounded effect of coal-dominated energy systems and heavily industrialized economies.



C02 Intensity and Prosperity 

On average, we see low carbon intensities at low incomes; carbon intensity rises as countries transition from low-to-middle incomes, especially in rapidly growing industrial economies; and as countries move towards higher incomes, carbon intensity falls again.



C02 intensity of goods imported and exported by country

Some countries take on emissions via trade.

The net emissions transfers here is the COembedded in imported goods minus the COembedded in exported goods. This tells us whether a country is a net exporter or importer of emissions.

Based on the updated data gathered by Peters et al. (2012) and the Global Carbon Project, if we switched to a consumption-based reporting system (which corrects for this trade), in 2014 the annual CO2 emissions of many European economies would increase by more than 30% (the UK by 38%; Sweden by 66%; and Belgium’s emissions would nearly double); and the USA’s emissions would increase by 7%.

On the other hand, China’s emissions would decrease by 13%; India’s by 9%; Russia’s by 14% and South Africa by 29%. The goods exported from Russia, China, India, and the Middle East typically have a high carbon intensity, reflecting the fact that their exports are often manufactured goods.

In contrast, we see that exports from the UK, France, Germany and Italy are low; this is likely to be the higher share of export of service-based exports relative to those produced from heavy industry.

Production vs consumption based emissions – If a country’s consumption-based emissions are higher than its production-based emissions then it is a net importer of CO2. If production-based emissions are higher, it is a net exporter.






3. Hannah Ritchie and Max Roser (2018) – “CO₂ and other Greenhouse Gas Emissions”. Published online at Retrieved from: ‘’ [Online Resource]































Potential Solutions To Freshwater Depletion & Scarcity

Solutions To Freshwater Depletion, Scarcity, Stress & Shortages

The world’s freshwater supplies are limited, and in a lot of cases depleting.

Depletion of these sources of freshwater include one off natural events, and more permanent problems like overpopulation and climate change (plus other factors).

Dry countries with hotter climates, and lower income countries with water access issues in particular face big freshwater issues that cause a severe impact on people, the economy, animals and the natural environment.

We’ve collated some of the best and most innovative ideas being used, or that might be worth developing further to solve issues like freshwater depletion, scarcity, stress and shortages.

Let’s take a look


Summary – Solutions To Freshwater Depletion

Some of the biggest positive changes might be see by addressing:

  • The Agricultural, Industrial & Household sectors – the three main areas we use freshwater in society
  • Population growth – more people means more demand for water directly, and also for all the indirect uses of water such as growing food, manufacturing products, producing energy, and running households
  • Capture waste/sewage/industrial/energy production/agricultural and household water, treat it, and re-use/recycle it where possible – waste water and grey water re-use and recycling, once treated, is one of the biggest potential ways to make better use of the water we use
  • Find more ways to capture/harvest rainwater – increased harvesting rainwater on farms, industrially, and at the household level, can give us more access to freshwater
  • Improve irrigation efficiency in agriculture – like for example drip irrigation and installing timers and sensors on irrigation systems. Making irrigation more efficient, and addressing water waste via irrigation, can save a lot of water
  • Improve industrial/commercial and energy production water efficiency – these two sectors use farm more water than the household sector. Becoming more efficient in these sectors can provide significant returns 
  • Reduce water waste, especially from water pipes and water infrastructure – at the household level, more water is wasted BEFORE it gets to our houses. Upgrading and improving water pipes and water infrastructure is one way to address this, as well as installing more water pipe damage software and sensors – just as some examples
  • Explore how to be more energy efficient with water desalination (and less costly) – desalination is currently very energy intensive and expensive. Reducing energy consumptions requirements (and cost) for desalination, or developing technology that allows desalination to occur with sustainable energy and green energy would go a long way to addressing this
  • Address water pollution – water pollution and contamination reduces the overall amount of freshwater available to our growing populations
  • Consider the impact of climate change on natural water replenishment – climate and temperature impacts the natural water replenishment cycle via evaporation, precipitation and so on


Specific Ways To Address Freshwater Depletion


Per (note: we’ve paraphrased the descriptions):

… Population growth, urban development, farm production and climate change are increasing competition for fresh water and producing shortages.

Here’s a look at the first 19 areas where experts feel needed solutions will come.

[these are areas where solutions for coping with water scarcity in business and industry may come based on a] … poll of more than 1200 leading international experts in 80 countries)


1. Educate people on the various water issues, and help people change consumption habits

Educate people on how important water is, how much of it we have, how much to use, where we use it and the consequences if we don’t address the issue and become sustainable with our use of it.

Specifically we want to educate people, and motivate them to change their behavior when it comes to consuming water

At all levels, and across the sections of society where we use the most water, we have to change consumption habits

We’ve got to use less water, and/or use water more efficiently


2. Invest in new water conservation technologies

Groundwater is drying up, and rainfalls are becoming inconsistent

Manufacturing equipment, waste water capture and re-use equipment, household equipment – all use water

Invest in technology that saves, re captures, cleans and re-uses water

Make sure new technologies are energy efficient, as energy use with water conservation or purification tech can be an issue


3. Recycle waste water

From industries, agriculture and households

Find a way to treat waste water and re-use/recycle it. Some places like Singapore are trying to find ways to treat and recycle wastewater for drinking for example


4. Improve agricultural and irrigation practices

These activities use a lot of water – up to 70% of total usage in some countries

Getting more efficient, using less water, and growing/producing different foods and crops can help

We can either create new practices and technology, or improve existing ones (such as existing irrigation technology – like they’ve done in California)


5. Increase the price of water 

If we stop making non drinking fresh water so cheap – maybe we can make people and businesses use less of it

It may also decrease water waste and pollution


6. Develop energy efficient water desalination

Desalination uses ALOT of energy – this is one of the major drawbacks to it

Considering 97% of the world’s water is saline water – if we get this technology right – it opens things up a lot

Renewable energy desalination plants are a good option – such as solar powered plants

Having said this – a country needs money in the first place to experiment with this type of technology, so it’s not an option for low income countries


7. Improve water catchment and harvesting

Water catchment and water harvesting can help us catch more freshwater that falls on the land and on structures

The more water we catch and harvest, the more we have available to use. You see this in dams that get extended

This is important for places struck by climate change, places with irregular rainfall, and places with low freshwater supplies


8. Look to community based governments and partnerships

Local governments and communities have power to empower people at a grassroots level

It can filter up to the national level when change occurs here


9. Develop, enact and maintain better laws and regulations

There’s the Clean Water Act in the US for example – which the US government is thinking of expanding

Whatever the case, national and state governments worldwide have an important part to play with both legislature, and their policies and decisions on how to manage freshwater sources

Many people believe it’s the government’s responsibility to provide us with freshwater


10. Holistically manage ecosystems

We are talking about economic, cultural, and ecological systems

This is making systems work together instead of just on their own

Good examples of holistic management are communities that operate sewage treatment plants while pursuing partnerships with clean energy producers to use wastewater to fertilize algae and other biofuel crops.

The crops, in turn, soak up nutrients and purify wastewater, significantly reducing pumping and treatment costs.


11. Improve distribution infrastructure

Poor water infrastructure can cause health, pollution/contamination and economic problems

We are talking about pipe bursts, lack of treatment facilities, sewage and wastewater overflows and malfunction


12. Shrink corporate water footprints

We are talking about producing products and goods, and sustainable manufacturing

Business activity and industrial activity (factories, manufacturing facilities etc.) uses up a large amount of water

Bottled water is one industry that is highly questioned – if we improve drinking water infrastructure – why do we need bottled water in the first place? Why don’t people refill their existing water bottles?


13. Build international frameworks and institutional cooperation

Work together to have better binding watter agreements and behaviors between countries

Hold each other to higher standards

Regional agreements regarding transboundary or shared water bodies, and treaties need more attention


14. Address water pollution (and contamination)

We are specifically talking about creating and maintaining better water quality

Poor water quality leads to human health and biodiversity issues

Contamination includes things like bacteria – E coli is an example

Pollution includes things like oil pollution, agricultural pollution and wastewater and sewage pollution


15. Public common resources/equitable access

Access to drinking water has to be a right for everyone in every country

Governments need to find a way to do this at least, even if water use for other purposes isn’t as efficient as it can be

The water crisis in lower income countries shows us what happens when drinking water is hard to come by or access


16. R&D/Innovation

Public private partnerships between business and governments

One example— cities that operate sewage treatment plants are likely to pursue partnerships with clean energy producers to fertilize algae and other biofuel crops with wastewater.


17. Water projects in developing countries/transfer of technology

Climate change and water scarcity are producing the most dramatic consequences in developing regions

One proposed solution is to transfer water conservation technologies from developed countries to these dry areas.

Doing so is tricky because economies are weak and there are gaps in skills that often compel government and business authorities to impose these changes on local citizens.


18. Climate change mitigation

Climate change (greenhouse gases in particular) and water scarcity go hand-in-hand

As renewable energy options are pursued, the water consumption of these mitigation tactics must be considered in producing alternatives ranging from bio-energy crops to hydropower and solar power plants.


19. Population growth control

Because of the accelerating growth in global population, parts of the world could see a supply-demand gap of up to 65 percent in water resources by 2030.

Currently, more than one billion people don’t have access to clean water.

And with 70 percent of the world’s freshwater used for agriculture, water’s critical role in food production must be considered as climate and resource conditions change.



1. Solar Powered Water Purifiers

Make more contaminated water drinkable

Use zinc oxide and titanium dioxide in containers that expose it to ultraviolet radiation and cleanse the water – making it suitable to drink


2. Water leak software and monitors

Almost a third of water is wasted even before it reaches a home – at failed and leaking pipelines. And, then obviously at the household level there can be over usage and wastage.

Water leak monitors and software with a central operating hub/control centre can help against this.


3. Replacing water cleaning, with CO2 cleaning

We use a lot of water in cleaning in manufacturing

To give you an idea of how much, manufacturing a car requires nearly 40,000 gallons of water

CO2 cleaning involves the use of carbon dioxide in solid form, highly propelled dry ice particles out of a nozzle to clean a variety of different surfaces.

The technology can be used for composite aircraft and automotive structures, cleaning complex medical equipment, and dry cleaning operations in an eco-friendly way.

The CO2 required for these machines is recycled from other industrial uses, so not only does it contribute to solving the water shortage crisis, but also helps with climate change.


4. Lifesaver bottles

For emergencies and short term water issues.

It’s a special bottle that can instantly make water potable. It uses a pump to push the water through a 15-nanometer filter which cleans it of any bacteria or viruses.

Has a low financial and environmental cost


5. Improving shower water saving technology

Technology that helps shower water heat up quicker, and technology that collects wasted cold water and refilters it in at the right temperature


6. Showering without water

A lotion has been made that has a blend of chemicals that get rid of odors, bioflavonoids and essential oils. The lotion can be applied right onto the skin and is as effective as taking a regular shower.

Dry Bathing can help save 4 liters of water per person which can add up to many millions every single year and help billions of people who don’t have access to water stay clean and avoid the life-threatening bacteria that’s often found in the stagnant water some of these people use to bathe.




The 2030 Water Resources Group has brought together case studies from around the world of currently available, replicable and practical solutions for water use transformation.

Some of these solutions include:

  • Waterless dying technology in textile processing
  • Installation of soil moisture monitoring system to improve productivity
  • Resource efficient cleaner production in sugar factories
  • Balancing supply and demand through water metering
  • Public private partnerships for water system upgrades
  • Partnerships for cleaner textile production
  • Institutional reform in irrigation management
  • Reducing the cost of water re-use in the textile sector
  • Integrated irrigation modernisation projects
  • Basin based approach for groundwater management
  • Innovative financing arrangements
  • Active supply chain management in the textile industry
  • Effluent treatment and aquifer storage for agricultural use
  • Innovative PPP to improve water quality and availability
  • Corporate water efficiency targets in the mining industry
  • Reducing water use in fish and seafood processing
  • Zero liquid discharge and water reuse at a coal power plant
  • PPP to address regional water issues
  • Adapting to water scarcity at farm level
  • Community implemented aquifer recharge scheme
  • Institutional capacity building approach to managing industrial water use
  • Integrated water resource management in agriculutre
  • Water management in copper and gold mines
  • Reuse of municipal effluent at a petrochemical complex
  • New water from fog catchingReducing water and energy consumption in a chemical plant
  • Satellite based spatial data to aid in irrigation
  • Micro irrigation for food security
  • Creation of ‘new water’ from saline aquifer
  • High frequency intermittent drip irrigation
  • Water free milk powder factory
  • Maximising water reuse at a brewery
  • Social norms based customer engagement on water efficiency
  • Installation of drip irrigation systems
  • Emergency response to drought crisis
  • Air flow dyeing machines in textile production
  • Water use reduction strategy in food sector
  • Water reuse in the textile sector
  • Water reuse in the power and steel production sector
  • Water recycling in the food sector
  • Water recycling in paper production
  • Water reclamation for reuse and groundwater recharge
  • Water optimisation in the mining sector
  • Use of seawater in dual municipal water supply
  • Regional water conservation program
  • Wastewater reclamation and reuse network
  • Water loss management programs
  • Water efficiency audits of steam systems
  • Reducing water losses in a large distribution network
  • Water demand management strategy
  • Water demand management scheme
  • Reducing business risk through municipal leakage reduction
  • Water authority conservation program
  • Pressure management in municipalities
  • Wastewater reclamation to meet potable water demand
  • Pilot low cost irrigation scheduling
  • Managing evapotranspiration using quotas
  • Mine water recycling
  • Leakage reduction in primary schools
  • Leakage reduction in cities
  • Metering of non revenue water
  • Irrigation scheduling in grape farming
  • Managing water towards zero discharge
  • Irrigation optimisation
  • Irrigation network renewal
  • Irrigation management
  • Integrated watershed management
  • Improving water availability through wastewater treatment
  • Improved water management for sugar cane production
  • Improved water distribution management
  • Groundwater recharge
  • Groundwater conservation
  • Emergency water demand management
  • Domestic and business retrofit project
  • Direct dry cooling in the power sector
  • Behavioral change initiative
  • Aquifer recharge with stormwater
  • Advanced pressure management



  • Farmers are partnering with scientists and conservationists to recharge groundwater by inundating farm fields with wintertime floodwater, which then seeps through the soil to the aquifer below
  • … Another neglected water source can be found right below our feet. The world’s soils can hold eight times more water than all rivers combined, yet agricultural practices deplete soils, causing that critical water reservoir to shrink.  But this can be fixed by rebuilding soil health.  
  • By eliminating tillage and planting cover crops, farmers can build the soil’s carbon content and enable it to store more water. Even a one percentage-point increase in soil organic carbon can increase water-holding capacity by some 18,000 gallons per acre. Yet farmers plant cover crops on less than 3% of US farmland and practice conservation agriculture on only about seven percent of cropland worldwide.


Further Ideas & Solutions

1. Consider changing our production and purchasing habits

Specifically with food and clothing.

Meat production, and cotton plants for example use a lot of water.

Switching to vegetarian diets, and switching to bamboo, hemp, lyocell and similar less water intensive fabrics – can all help.


2. Decrease water contamination, and invest more cheap/efficient water contamination technology

Water contamination, particularly with E coli and bacteria, is a big problem

If we can decrease contamination (protect water sources better) and get better at treating water contamination in it – more water will be available in contaminated water sources


3. Decrease water pollution

Mostly pollution from agriculture (fertiliser, herbicide and pesticide) and waste water and sewage treatment pollutes water

Decrease this pollution, and get better at cleaning up pollution







Freshwater Supply & Usage Around The World: How Much Freshwater We Have, How Much We Use, & How We Use It

Freshwater Supply & Usage Around The World: How Much Freshwater We Have, How Much We Use, & How We Use It

Freshwater supplies and usage/withdrawal rates around the world differ by country.

How much freshwater we have, how much of it we use and what we use it on are all important stats and trends to look at so we can manage our water resources within each country.

We take a look at these stats and certain trends and patterns in this guide.


Summary Of Freshwater Worldwide

  • We have different types of freshwater sources in the world – some are more renewable than others
  • Freshwater is distributed unequally all over the world – some countries have huge natural freshwater supplies, and some are very water scarce
  • Freshwater usage is only increasing as population increases 
  • Freshwater is used in the three following areas in society – agriculture, industry (energy generation and business), and municipal (household). Agriculture usually uses the most (around 70% of total), but in some countries industry uses almost as much as agriculture. Household usually uses about 10% or less.


Different Types Of Freshwater Sources

One of the most important freshwater sources to know about is renewable water resources.

These are defined as the average manual flow of rivers and recharge of aquifers generated from precipitation (precipitation from the atmosphere is what fills freshwater sources).

In layman’s terms – these are sources that are regenerated from the natural water cycle of rainfall, use and evaporation – and the cycle repeats itself.

From a sustainability perspective, if withdrawal rates (how much freshwater a country uses) stays within the renewable water supply rate, a country should have a better chance of staying out of water stress or water shortage territory (but there’s also natural events, climate change, socio-economic factors and other factors that can affect water supply).


According to, there are different types of freshwater sources such as:

  • Renewable freshwater sources – renewed by the water cycle. They represent the long-term average annual flow of rivers (surface water) and groundwater.
  • Non renewable freshwater sources – groundwater bodies (deep aquifers) that have a negligible rate of recharge on the human time-scale and thus can be considered non-renewable.
  • Natural freshwater sources – the total amount of a country’s water resources (internal and external resources), both surface water and groundwater, which is generated through the hydrological cycle
  • Human (actual) influenced freshwater sources – the sum of internal renewable resources (IRWR) and external renewable resources (ERWR), taking into consideration the quantity of flow reserved to upstream and downstream countries through formal or informal agreements or treaties and possible reduction of external flow due to upstream water abstraction. Unlike natural renewable water resources, actual renewable water resources vary with time and consumption patterns and, therefore, must be associated to a specific year.
  • Internal freshwater sources – water resources (surface water and groundwater) generated from endogenous precipitation i.e. water from within the country itself
  • External freshwater sources –  the part of a country’s renewable water resources that enter from upstream countries through rivers (external surface water) or aquifers (external groundwater resources) i.e. water from other countries
  • Surface Freshwater – rivers, lakes, streams etc. that are above ground
  • Groundwater Freshwater – underground aquifers of water


When freshwater sources are talked about, often the water quality is not taken into consideration i.e. whether it is contaminated, polluted or not suitable to drink or use.

Freshwater though does naturally contain a very little amount of dissolved salts and naturally occurs on the surface of the earth in lakes, rivers, caps, streams, ponds, icebergs, glaciers, and ponds.

Freshwater sources do not usually account for brackish, saline and non-conventional water sources.

You can read more about the different types of freshwater sources here – 


Freshwater Supply By Country

According to, total freshwater supplies in kilometres cubed (km3) are:

  1. Brazil – 8233
  2. Russia – 4508
  3. United States – 3069
  4. Canada – 2902
  5. China – 2840
  6. Colombia – 2132
  7. European Union – 2057
  8. Indonesia – 2019
  9. Peru – 1913
  10. India – 1911
  11. Democratic Republic Of The Congo – 1283
  12. Venezuela – 1233
  13. Bangladesh – 1227
  14. Myanmar – 1168
  15. Nigeria – 950

WorldAtlas describes where most of the freshwater in each of these countries is found, so their guide is worth a read.


Wikipedia also shows an extended list of 172 countries (which you can find in the sources part of this guide).


According to Food and Agriculture Organization, AQUASTAT data, and via, Renewable internal freshwater resources (internal river flows and groundwater from rainfall) per capita (per person, in cubic metres) worldwide are as follows:

5Papua New Guinea103,277.802014
9Solomon Islands77,671.052014
11New Zealand72,510.372014


How Is Freshwater Distributed By Sources


Of the Earth’s water, 97 percent is saline while 3 percent is freshwater (with low concentrations of dissolved salts and other total dissolved solids).

  • Nearly 69 percent is held in glaciers and ice caps.
  • Another 30 percent is groundwater that is held in underground soil and rock crevices
  • The remaining one percent is surface water and other sources.
  • Of that water considered to be surface water, 87 percent exists in lakes, 11 percent in swamps, and 2 percent in rivers.
  • The American Great Lakes account for 21 percent of the Earth’s surface fresh water.
  • Lake Baikal in Russia is considered the deepest, oldest freshwater lake in the world. It holds about 20 percent of the Earth’s unfrozen surface fresh water, the largest volume in the world.
  • Lake Victoria, which spreads across the African countries of Kenya, Uganda, and Tanzania, is the second largest freshwater lake in the world by surface area.
  • Africa’s Lake Tanganyika is the second deepest freshwater lake, and holds the second largest volume of fresh water. It’s the longest lake, and extends across Burundi, Zambia, Tanzania, and the Democratic Republic of Congo.

Different countries and states across the globe have their freshwater located in different sources, and access their usable and drinkable water from different sources.

If we take Indiana in the US as an example, groundwater supplies approximately 60 percent of the treated water delivered to homes and businesses for drinking, bathing, chores, and more. In a 2 year span, Indiana American Water proactively invested more than $130 million in its water and wastewater infrastructure around the state –

You can read more about how much water we have on earth


Variables That Can Affect Available Freshwater Supplies

A country may have enough freshwater for drinking and use, but people and businesses in that country may not get access to the water.

A country may also have declining freshwater supplies year on year despite not being a high usage country.

Why does this happen? Well, it can be for a few reasons:

  • Barriers to freshwater access – barriers can be physical or economic. Freshwater sources may be difficult from a logistical level to access, or the country may be a low income/low GDP country and may not financially be able to build and maintain water access infrastructure and equipment
  • Contamination and pollution of freshwater sources which lessens water quality – there may be access to freshwater, but those freshwater sources might not be well protected against potential contaminants (especially bacteria like E coli) and pollution
  • Poor governance and freshwater management plans – there may be enough freshwater supply and access to the water, but the water usage and management plans in place may not be adequate
  • Natural events – droughts, heat waves, floods (can cause contamination), change of seasons and monsoons, can all temporarily affect water supply levels
  • Human induced events – climate change and global warming can decrease freshwater supply levels

There are several water based issues we face on a global and at country levels that have their own set of problems, solutions and limitations 


Freshwater Usage On A Global Level

  • A growing global population and economic shift towards more resource-intensive consumption patterns means global freshwater use — that is, freshwater withdrawals for agriculture, industry and municipal uses — has increased nearly six-fold since 1900.
  • Rates of global freshwater use increased sharply from the 1950s onwards, but since 2000 appears to be plateauing, or at least slowing.
  • Evidence of that can be seen by looking at 2004 where the global population used 3.85 trillion cubic metres of freshwater, and 2014 where the global population used 3.99 trillion cubic metres of freshwater



Freshwater Usage/Withdrawal By Country (Withdrawal Rate)

Total Freshwater Withdrawals

Per, in 2014, the biggest users of freshwater were:

  • India had the largest freshwater withdrawals at over 760 billion cubic metres per year.
  • This was followed by China at just over 600 billion m
  • United States at 480-90 billion m3
  • Pakistan at 183.5 billion m3
  • and, Indonesia at 113.3 billion m3


Freshwater Withdrawals Per Capita, Per Year

Per, in 2010, the biggest users of freshwater per person were:

  • Iceland – 11,042 cubic metres (per person, per year)
  • Turkmenistan – 5,753 cubic metres
  • Chile – 2152 cubic metres
  • Uzbekistan – 2106 cubic metres


Renewable Internal Freshwater Withdrawals Per Capita

Renewable internal freshwater resources refers to the quantity of internal freshwater from inflowing river basins and recharging ground water aquifers.

According to OurWorldInData:

Per capita renewable resources depend on two factors: the total quantity of renewable flows, and the size of the population.

If renewable resources decline — as can happen frequently in countries with large annual variability in rainfall, such as monsoon seasons — then per capita renewable withdrawals will also fall. Similarly, if total renewable sources remain constant, per capita levels can fall if a country’s population is growing.

The trends we see for a lot of countries is a slow decline in renewable internal freshwater supplies based on withdrawal rates.

Brazil by far has the biggest per capita supply decrease from 1962 to 2014, going from over 70,000 cubic metres of water, to under 30,000 cubic metres.

In that same time span, the United States has gone from 15,106 cubic metres to 8,845 cubic metres.

China has gone from 4,225 cubic metres, to 2,016 cubic metres.

Average per person, per year, renewable freshwater withdrawal rates by region are as follows (in cubic metres):

  • South America – 30,428
  • Oceania – 29,225
  • Eastern Europe – 21,383
  • North America – 12,537
  • Central America and Caribbean – 8,397
  • Western & Central Europe – 4,006
  • Sub Saharan Africa – 3,879


Freshwater Usage/Withdrawal By Industry & Sectors (How & Where We Use Water)

Per findings and stats by 


Agriculture Water Usage/Withdrawal

Water is used in agriculture (food crop, livestock, biofuels, or other non-food crop production) from both rainfall, and pumped irrigation.

In 2010 India was the world’s largest agricultural water consumer at nearly 700 billion m3 per year. India’s agricultural water consumption has been growing rapidly  — almost doubling between 1975 and 2010 — as its population and total food demand continues to increase. China is the world’s second largest user, at approximately 385 billion min 2015, although its agricultural freshwater use has approximately plateaued in the recent past.

Globally we use approximately 70 percent of freshwater withdrawals for agriculture.

  • However, this share varies significantly by country – as shown in the chart below which measures the percentage of total freshwater withdrawals used for agriculture. Here we see large variations geographically and by income level. The average agricultural water use for low-income countries is 90 percent; 79 percent for middle income and only 41 percent at high incomes.
  • There are a number of countries across South Asia, Africa and Latin America which use more than 90 percent of water withdrawals for agriculture. The highest is Afghanistan at 99 percent. Countries in the global north tend to use a much lower share of water for agriculture; Germany and the Netherlands use less than one percent.


Irrigation Water Usage/Withdrawal 

Irrigation is the deliberate provision or controlled flooding of agricultural land with water.

The share of total agricultural area (which is the combination of arable and grazing land) which is irrigated:

  • is particularly prevalent across South & East Asia and the Middle East;  Pakistan, Bangladesh and South Korea all irrigate more than half of their agricultural area. India irrigates 35 percent of its agricultural area.
  • Levels of irrigation in Sub-Saharan Africa have increased, and continue to have, lower levels  of irrigation relative to South Asia and the Middle East & North Africa. Poorer progress in increasing crop yields in recent decades in Sub-Saharan Africa has been partly attributed (among other factors including fertilizer application rates and crop varieties) to lower uptake of irrigation in Sub-Saharan Africa.


Industrial (Business) Water Usage/Withdrawal

Water is used in industries and business in dilution, steam generation, washing, and cooling of manufacturing equipment. as well as cooling water for energy generation in fossil fuel and nuclear power plants (hydropower generation is not included in this category), or as wastewater from certain industrial processes.

  • The United States is the largest user of industrial water, withdrawing over 300 billion m³ per year.
  • This is significantly greater than China, the second largest, at 140 billion m³
  • Most countries across the Americas, Europe and East Asia & Pacific regions use more one billion m³ for industrial uses per year. Rates are typically much lower across Sub-Saharan Africa and some parts of South Asia where most use less than 500 million m³.

Globally, just under 20 percent (18-19 percent) of total water withdrawals are used for industrial purposes.

  • In contrast to the global distribution for agricultural water withdrawals, industrial water tends to dominate in high-income countries (with an average of 44 percent), and is small in low-income countries on average 3 percent).
  • Estonia uses the greater share of withdrawals for industrial applications at 96 percent. The share in Central and Eastern Europe tends to be greater than 70 percent; 80 percent in Canada; and approximately half in the United States. Across Sub-Saharan Africa and South Asia, this tends to contribute less than 10 percent to total withdrawals.


Municipal (household) Water Usage/Withdrawal 

The water we use for domestic, household purposes or public services. This is typically the most ‘visible’ form of water: the water we use for drinking, cleaning, washing, and cooking.

  • With the largest population, China’s domestic water demands are highest at over 70 billion m³ per year.
  • India, the next largest populace is the third largest municipal water user.
  • The United States, despite having a much lower population, is the second largest user as a result of higher per capita water demands.

Despite being the most visible use of freshwater, domestic demands for most countries are small relative to agricultural and industrial applications. Globally around 11 percent of withdrawals are used for municipal purposes.

  • The majority of countries use less than 30 percent of withdrawals for domestic purposes.
  • The share of municipal water in some countries across Sub-Saharan Africa can be high as a result of very low demands for agricultural and industrial withdrawals.
  • Domestic uses of water withdrawals can also dominate in some countries across Europe with high rainfall, such as the United Kingdom and Ireland where agricultural production is often largely rain fed and industrial output is low.



1. Hannah Ritchie and Max Roser (2018) – “Water Access, Resources & Sanitation”. Published online at Retrieved from: ‘’ [Online Resource]








The Water Crisis: Access To Usable Freshwater, & Clean/Safe Drinking Water

Lack Of Access To Clean/Usable Water, & Drinking Water

There are a number of different issues when it comes to water as a resource in different parts of the world.

One of those issues is being able to access safe/clean freshwater, to both use and drink.

Some countries have never had access to, or have had problems accessing safe/clean water to drink and to use – and these countries are sometimes referred to as being in a ‘water crisis’.

In this guide we discuss what the water crisis is, what causes access issues, the effects of a lack of sufficient access to non contaminated water, countries most affected, and how we can solve and prevent these water crisis issues.


Summary – What To Know About The Water Crisis

The water crisis is when there is a lack of access to safe and clean freshwater to either use or drink.

Low income and poverty stricken countries, those with high water pollution and contamination rates, those with small freshwater reserves (water scarce countries), rural areas, and high populated place can have issues with clean water access, and supply of fresh drinking water.

The solution depends on the circumstances of the water crisis – but it is usually multi pronged.

What is clear though is that clean and safe water is critical to any society to function and grow.

The impacts of having a lack of freshwater or clean drinking water are wide ranging and can be both life threatening and catastrophic.


The Different Global Water Issues

Before we get into talking about the water crisis in more depth, it’s important to get a general idea of the different water issues.

You can read a guide detailing the different global water issues and terms/phrases used to describe them here.

It’s really water access, and water quality we are talking about when we talk about the water crisis.

To put it in layman’s terms, the main steps finding for water to use or drink are:

  • find a freshwater source or sources
  • access it < main part of the water crisis
  • assess the quality of the water to make sure it’s suitable to use or drink, and treat it if necessary before using or drinking < part of the water crisis
  • make sure it stays protected from contamination or pollution while in use < part of the water crisis
  • manage the water source in terms of supply, withdrawal rates, natural events like droughts, growth in population, climate change etc.


The Water Crisis: Access To Usable Freshwater, & Clean/Safe Drinking Water

When we talk about the water crisis, we are mainly focussing on countries and regions that:

  • Don’t have sufficient physical or economic access to freshwater
  • Don’t have sufficiently protected freshwater to drink (protected against contamination or pollution that might make it unsafe to drink)
  • Don’t have sufficiently protected freshwater to use (protected against contamination or pollution that might make it unsafe to use). Note that water can be unsafe to drink, but safe to use for cleaning for example
  • Or, a combination of these factors/issues

The water crisis mainly affects low income/developing countries with access issues, but water quality in particular can affect developed countries (like the Flint, Michigan event).

It’s very important to note that there can be access/improved access to freshwater, but that doesn’t mean the water is of a quality to use or drink. Water quality is a separate issue to water access.


Improved Water Sources, & ‘Safe’ Water Sources For Drinking

One of the goals with water access is to get access to an improved water source. This can be defined as:

  • “An improved drinking water source includes piped water on premises (piped household water connection located inside the user’s dwelling, plot or yard), and other improved drinking water sources (public taps or standpipes, tube wells or boreholes, protected dug wells, protected springs, and rainwater collection).
  • Access to drinking water from an improved source does not ensure that the water is safe or adequate, as these characteristics are not tested at the time of survey.
  • But improved drinking water technologies are more likely than those characterized as unimproved to provide safe drinking water and to prevent contact with human excreta.
  • While information on access to an improved water source is widely used, it is extremely subjective, and such terms as safe, improved, adequate, and reasonable may have different meanings in different countries despite official WHO definitions.
  • Even in high-income countries treated water may not always be safe to drink.
  • Access to an improved water source is equated with connection to a supply system; it does not take into account variations in the quality and cost (broadly defined) of the service.”

– WorldBank, & UNICEF/WHO, via


Per WHO/UNICEF, via the

  • Some sources protect against contamination, but it still might not be safe to drink the water.
  • To be considered “safe”, a source of drinking water must be free from pathogens and high levels of harmful substances. Globally, the main health concern is faecal contamination, which is identified by the presence of bacteria such as E.coli.
  • In many places, a water point is designed to protect against contamination, but the water from it might still have traces of E.coli – the groundwater may be contaminated by faulty latrines, or the containers people use to carry and store water may contain traces of the bacteria.
  • In Nepal, 91% of the population drink from an improved water source, but E.coli has still been detected.


Causes Of Lack Of Access To Usable Freshwater, & Clean/Safe Drinking Water

Some of the major causes of a lack of clean usable water and safe drinking water in a country or region are:

  • Being a low income/low GDP country – not having the economic/financial capacity to set up and maintain safe access to freshwater. This is the main cause and it affects many African countries
  • Having high rates of water contamination and pollution – even if there is access to water, contamination lessens the water quality for use and drinking (e.g. it might have bacteria or pathogens in it, or get waste regularly dumped in it)
  • Not having large renewable freshwater reserves – limits the total available amount of freshwater accessible to use or drink
  • Living in a rural area – rural areas generally have bigger access issues than urban areas
  • Population growth and overpopulation – places increased economic and logistical strain on water access


Effects Of Lack Of Access To Usable Freshwater, & Clean/Safe Drinking Water

Humans depend on freshwater for almost every major thing we do in our societies, with notable things being:

  • Drinking
  • Cleaning
  • Food Production and Agriculture
  • Industrial & Commercial Output (Business Activity)

On top of that, the animals and natural environment around us need clean water to survive and thrive.


When there is a lack of clean usable water or drinking water, the following effects can occur:

  • Poor Human Health – examples are malnutrition (not drinking enough water), and higher rates of the transmission of infectious diseases such as diarrhoea, cholera, dysentery, typhoid, and polio. This is particularly the case with contaminated water and when there is a lack of water for proper sanitation –
  • Higher Spending on Public Health – more water access or water quality related health problems means more of a government’s expenditure must go towards health when it could go to other things.
  • Death and Higher Mortality Rates – Particularly with children. The WHO estimates that in 2015, the deaths of 361,000 children under 5-years-old could have been avoided by addressing water and sanitation risk factors. – WHO/
  • Poverty and Lack of Economic Growth – water access and water quality related issues contribute to poverty because obviously people either can’t work at all, or can’t work productively. In addition, the freshwater supplies aren’t there to run and grow business and economic activity. It’s worth noting that in countries where people have to walk longer distances to get water, this cuts into time they could spend working and earning money. Women and children in particular spend 258 million hours every day worldwide collecting water. This is time spent not working, caring for family members or attending school. –
  • Lack of Sanitation and Hygienesanitation and hygiene depend on available clean water
  • Lack Of Safety – walking long distances to get water can increase the risk of being assaulted or harmed – especially for women and children
  • Lack Of Education – if children have to walk to get water for themselves and their families, they miss out on school to do this


Trends And Progress In Access To Improved Water Sources, & Drinking Water


  • Access to improved water sources is increasing across the world overall, rising from 76 percent of the global population in 1990 to 91 percent in 2015.
  • This marks significant progress since 1990 where most countries across Latin America, East and South Asia, and Sub-Saharan Africa were often well below 90 percent.
  • In 1990, 1.26 billion people across the world did not have access to an improved drinking water source. By 2015, this had nearly halved to 666 million.
  • In 1990, 4 billion people had access to an improved water source; by 2015 this had increased to 6.7 billion. This means that over these 25 years the average increase of the number of people with access to improved drinking water was 107 million every year. These are on average 290,000 people who gained access to drinking water every single day.
  • In 1990 nearly 42 percent of those without access to an improved water source were in East Asia & the Pacific. By 2015, this had fallen to 20 percent. In contrast, Sub-Saharan Africa was host to 22 percent of those without water access in 1990; by 2015 this had increased to nearly half of the global total.
  • The absolute number of people without access has fallen across all regions over this 25-year period with the exception of Sub-Saharan Africa. The number of people in Sub-Saharan Africa without access to an improved water source has increased from 271 million to 326 million in 2015.
  • Access in current times remains lowest in Sub-Saharan Africa where rates typically range from 40 to 80 percent of households.
  • The share of rural households with improved water sources was lower than the total population in 2015, with 85 percent access. Gaining access to improved water sources can often require infrastructural investment and connection to municipal water networks; this is can be more challenging in rural areas hence we may expect access to be lower. Nonetheless, rural access has risen at a faster rate (based on the relative increase in the share of the population) than total access, increasing by 22 percent since 1990. –
  • Globally 97 percent of urban households had improved water access, with most nations now having close to 100 percent penetration.


Per, in 2018:

  • In 2015, 71% of the global population (5.2 billion people) used a safely managed drinking-water service – that is, one located on premises, available when needed, and free from contamination.
  • 89% of the global population (6.5 billion people) used at least a basic service. A basic service is an improved drinking-water source within a round trip of 30 minutes to collect water.
  • 844 million people lack even a basic drinking-water service, including 159 million people who are dependent on surface water.
  • Globally, at least 2 billion people use a drinking water source contaminated with faeces.
  • Contaminated water can transmit diseases such diarrhoea, cholera, dysentery, typhoid, and polio. Contaminated drinking water is estimated to cause 502 000 diarrhoeal deaths each year.
  • By 2025, half of the world’s population will be living in water-stressed areas.
  • In low- and middle-income countries, 38% of health care facilities lack an improved water source, 19% do not have improved sanitation, and 35% lack water and soap for handwashing.


Also per

  • 1.3 billion people with basic services, meaning an improved water source located within a round trip of 30 minutes
  • 263 million people with limited services, or an improved water source requiring more than 30 minutes to collect water
  • 423 million people taking water from unprotected wells and springs
  • 159 million people collecting untreated surface water from lakes, ponds, rivers and streams.


Per WHO/UNICEF, via the In 2015:

  • 663 million people – one in 10 – still drank water from unprotected sources (a protected source protects against contamination, whereas an unprotected one doesn’t).
  • In 41 countries, a fifth of people drink water from a source that is not protected from contamination
  • In most countries, the majority of people spend less than 30 minutes collecting water, or have a piped supply within their home. But in some regions, especially sub-Saharan Africa, many people spend more than 30 minutes – and some more than an hour – on each trip to collect water. This burden still falls mainly on women and girls – they are responsible for this task in eight in 10 households that don’t have a piped supply.
  • Mongolia is the only country where men and boys have primary responsibility for collecting water
  • In many parts of the world, water isn’t available all day everyday. In some provinces of South Africa, water supply in 60% of households has been interrupted for two days or more. In South Africa in 2014, a fifth of households with municipal piped water had interruptions that lasted for more than two days. This was three times higher in some regions of the country. Few countries have water available continuously, but in many parts of the world a less than 24-hour supply is still considered sufficient. Countries use a wide range of different measures to assess availability and these must match up so that comparisons of service levels can be made across countries and over time.
  • The cost of drinking water and sanitation is different in different countries – In Tanzania, 10% of the population spend more than 5% of their expenditure on drinking water


Countries & Places Without Access To Drinking Water

Access in 2015 remains lowest in Sub-Saharan Africa where rates typically range from 40 to 80 percent of households. 

The number of people in Sub-Saharan Africa without access to an improved water source has increased from 271 million in 2990, to 326 million in 2015. 

To put these numbers in context, almost half of people drinking water from unprotected sources worldwide live in sub-Saharan Africa, and eight in 10 live in rural areas.

East Asia and The Pacific make up 133 million, and South Asia also makes up 133 million. 



Countries With Water Pollution & Contamination Issues

Read more about water pollution and countries with water pollution issues in this guide 


Potential Solutions To Lack Of Clean Water, & Lack Of Drinking Water

Potential solution to manage and solve the water crisis might be:

  • Specifically provide aid and donations to low income countries and regions to help improve clean water access with infrastructure and water treatment technology
  • Aid, and investment in low income countries to help build them up economically so they can build and maintain clean water access equipment and technology
  • Reduce and better manage water pollution and contamination
  • Use water more efficiently at the household and business/commercial/industrial levels – particularly in high water stress countries
  • Better water management plans from the government level – particularly in high water stress countries
  • Adjust household, business and food production/agriculture activity in water stressed countries to activity that doesn’t use as much water e.g. switch to growing food that uses less water
  • Invest in freshwater supply technology (like desalination plants) – particularly in highly water stressed countries
  • Re-use of wastewater, to recover water, nutrients, or energy, is becoming an important strategy. Increasingly countries are using wastewater for irrigation – in developing countries this represents 7% of irrigated land. While this practice if done inappropriately poses health risks, safe management of wastewater can yield multiple benefits, including increased food production.
  • Invest more in low-cost techniques to test the quality of water people drink, especially for those who are not connected to regulated piped networks.


When looking at a water crisis solution, these notes can be considered:

  • Access to improved water sources generally increases with income of the country
  • Urban areas generally have better access to freshwater than rural areas
  • Agricultural water withdrawals tend to be higher at lower incomes
  • Globally, 70 percent of water withdrawals are used for agriculture. However, water requirements vary significantly depending on food type. Different foods have different water footprints
  • Different industries and sectors have different water footprints e.g. agriculture and textile industries are big water users



1. Hannah Ritchie and Max Roser (2018) – “Water Access, Resources & Sanitation”. Published online at Retrieved from: ‘’ [Online Resource]