Potential Solutions For Reducing Greenhouse Gas & Carbon Emissions In Agriculture, Forestry & Other Land Use Sources (AFOLU)

Together, agriculture, forestry & other land uses are responsible for a significant amount of greenhouse gas emissions globally. 

In this guide, we look at potential solutions for reducing emissions from agriculture, forestry and land use.

 

Summary – Solutions For Reducing Agriculture, Forestry & Other Land Use Greenhouse Gas Emissions

Agriculture, land use and forestry are linked together when it comes to greenhouse gas emissions

Agriculture is one form of land use, and forests and vegetation can be cleared and converted to ranches, farms and other land uses 

Agriculture is mainly an emitter, whilst the act of deforestation also contributes to emissions and climate change (as it can remove carbon sinks, and also change the surface of Earth to impact how heat is absorbed or reflected – after the burning of fossil fuels at 87%, deforestation is actually the second major cause of climate change at 9%)

Forests and vegetation are usually a net carbon sink, storing carbon in plant biomass, but also below ground in soil. Vegetation is also capable of emitting gases and VOCs though

Some of the main gases emitted in agriculture are nitrous oxide, which comes from mainly synthetic fertilizer; and methane, which comes principally from rice and livestock. But, carbon dioxide is also emitted in the agricultural sector

In the US, current numbers indicate fertilizer is responsible for 50% of emissions, livestock around 33%, and manure about 15%

Australian sources say livestock are the biggest emitters – The largest portion of greenhouse gas emissions in agriculture usually comes from livestock and their digestive systems – burping, farting, manure, urine etc (agric.wa.gov.au)

Potential solutions for addressing emissions in each area might include … 

 

Agriculture

Adjusting land, livestock and crop management – using fertilizers that minimize pollution and emissions (such as more organic fertilizers), finding better ways to drain water from waterlogged rice paddy crop soil (or growing different less water intensive crops to rice), increasing crop and livestock production efficiency

Reducing the emission of methane from livestock – can involve changing food stock quality, genetic engineering, improving breeding practices, decreasing total livestock numbers, or decreasing numbers of some of the biggest livestock types (like cows) that have the most intensive emissions per livestock animal. 

Reducing emissions from manure – via re-using manure as a fertilizer and capturing gas from manure in containment and using it for energy

Better soil management – Another portion of greenhouse gas emissions comes for soil management – mainly the nitrogen lifecycle from anaerobic or water logged soil with higher nitrogen fertilizer application rates (agriculture.vic.gov.au). So, fertilizer and soil management here are key

Consumers may also have a role by considering the carbon footprint of their diet and the foods they eat – Read a guide here about the carbon footprint of different types of food. Reducing food waste and loss can also help 

 

Land Use

Changing uses of land by decreasing the amount of forest that is converted for other land uses, and avoiding land degradation in general

Using more sustainable farming practices and methods that preserve soil and land better

Planting more trees and vegetation after tree and vegetation loss, and restoring land of land degradation to maximize soil carbon storage

 

Forestry

Higher rates of reforestation and afforestation – especially in areas that suffer from high deforestation rates

Protecting and conserving existing forests, especially tropical rainforests and biodiverse forest areas

 

*Note – every country has a different greenhouse gas emission profile (because their industries are all different sizes, and they might have different production processes to each other). The above are general solutions, but, a greenhouse gas solution plan should be put together for each individual country, state/province, or city. China and the US are of particular significance as they are currently the two biggest annual emitters of GHGs. But, we could also focus on the countries with the highest agricultural emissions as well.

*Also note – nap.edu identifies that AFOLU carries the most uncertainty of all the major GHG emitting sectors – due to factors like the standing biomass of tropical forests being uncertain, among other factors. Rather than paying attention to GHG emission numbers, they say it might be more wise to pay attention to the overall trends for emissions e.g. deforestation overall decreases the amount of CO2 being sequestered, and as another example, increased total livestock numbers increases greenhouse emissions (from methane etc.)

 

Global Greenhouse Gas Emissions By Sector, & In Agriculture & Land Use/Forestry

Read more in this guide about the industries that emit the most greenhouse gases and CO2 – both globally, and in individual countries.

As one excerpt … 

In 2010, the total global greenhouse gas emissions by sector globally, measured in gigagrams of carbon-dioxide equivalents (CO₂e), were:

  • Total – 50.58 million
  • Energy – 23.24 million
  • Land Use Sources – 5.54 million
  • Transport – 5.54 million
  • Agriculture – 5.08 million
  • Commercial & Residential – 3.74 million
  • Industry – 3.47 million
  • Waste – 1.45 million
  • Forestry – 1.18 million
  • International Bunkers – 1.08 million
  • Other Sources – 267,609.41 thousand

– ourworldindata.org

But, as mentioned, each country has a different emissions share by sector, so look at individual country greenhouse gas numbers too (and not just the numbers of one country, or global numbers). Also, note that different sectors emit different types of GHGs in different quantities (e.g. methane from agriculture needs to be considered).

 

Globally, deforestation is a major source of emissions:

  • Deforestation is the second largest anthropogenic source of carbon dioxide to the atmosphere, after fossil fuel combustion.
  • Deforestation and forest degradation contribute to atmospheric greenhouse gas emissions through combustion of forest biomass and decomposition of remaining plant material and soil carbon.
  • It used to account for more than 20% of carbon dioxide emissions, but is currently around the 10% mark

– wikipedia.org

 

Specifically in the US for agriculture:

  • Agriculture directly accounts for 10-12 percent of anthropogenic greenhouse gas emissions [in the US]

– theconversation.com

 

Potential Options/Solutions For Reducing Greenhouse Gas & CO2 Emissions In Agriculture & Land Use/Forestry

EPA.gov outlines some of the following solutions (paraphrased):

Agriculture

  • Land and Crop Management – Adjusting the methods for managing land and growing crops [e.g. using the right type and amount of fertilizer on crops, and draining water from rice crops instead of letting it sit]
  • Livestock Management – Adjusting feeding practices and other management methods to reduce the amount of methane resulting from enteric fermentation [e.g. improving pasture quality to increase animal productivity, and improving livestock breeding practices]
  • Manure Management – Controlling the way in which manure decomposes to reduce nitrous oxide and methane emissions, and capturing methane from manure decomposition to produce renewable energy. [e.g. handling manure as solid or using it as a fertilizer, capture energy from manure in anaerobic containment]

Land Use & Forestry

  • Change in Uses of Land – Increasing carbon storage by using land differently, or maintaining carbon storage by avoiding land degradation [e.g. Minimizing the conversion of forest land to other land uses, such as settlements, croplands, or grasslands.]
  • Changes in Land Management Practices – Improving management practices on existing land-use types. [e.g. Utilizing reduced tillage practices on cropland and improved grazing management practices on grassland., and planting after natural or human-induced forest disturbances to accelerate vegetation growth and minimize soil carbon losses]

 

There are 4 main approaches to mitigating livestock greenhouse gas emissions:

  • Husbandry (animal breeding, feed supplements, improved pastures)
  • Management systems (stocking rates, biological control)
  • Numbers of livestock
  • Manure management

– agric.wa.gov.au

 

  • The two main current strategies to reduce agriculture emissions are … 1) The widespread dissemination of technical agronomic practices in livestock, cropland and paddy rice management, and 2) One that shows increases in the efficiency of crop and livestock production.
  • Other future options might include breeding livestock to produce less methane, producing crops that need less fertilizer, alternate wetting and drying in irrigated rice, more intense/productive livestock practices (increases productivity and lifetime emissions)
  • Improving feed, managing herd sizes, improving animal health and strategic breeding all enable more GHG-efficient agriculture by reducing emissions per kilogram of milk or beef
  • [Financing, awareness of new technology and practices, and bringing this to the farmers – are some of the barriers/challenges currently faced]

– theconversation.com

 

Economics Of Reducing Energy GHG & Carbon Emissions In Agriculture & Land Use/Forestry

Some potential abatement costs and potential greenhouse gas savings of different agricultural, land use and forestry actions can be found at

  • https://ourworldindata.org/how-much-will-it-cost-to-mitigate-climate-change.

Options like reforestation, afforestation, soil restoration, cropland nutrient management, rice management, and so on, are all mentioned.

 

Emissions Breakdown, & Emission Trends In Agriculture & Land Use/Forestry

It’s important to know information such as the prevalent greenhouse gas, exactly where emissions are coming from (the source), and trends over time in a sector.

 

In the US:

Agriculture

  • [GHGs come] from livestock such as cows, agricultural soils, and rice production.
  • Nitrous oxide can come from synthetic fertilizers, methane can come from the normal digestive processes of livestock, nitrous oxide and methane can come from manure management, and some CO2 can come from other farming activities
  • Management of agricultural soils (fertilizer etc.) accounts for over half of the emissions from the Agriculture economic sector
  • [Methane from livestock] represents almost one third of the emissions from the Agriculture economic sector
  • Manure management accounts for about 15 percent of the total greenhouse gas emissions from the Agriculture economic sector in the United States

Land Use & Forestry

  • Emissions or sequestration of CO2, CH4 and N2O can occur from management of lands in their current use or as lands are converted to other uses
  • Land areas [plants, trees, soils etc.] can act as a sink (absorbing CO2 from the atmosphere) or a source of greenhouse gas emissions. In the United States, since 1990, managed forests and other lands have absorbed more CO2 from the atmosphere than they emit [the more forests and vegetation/plants that remain compared to land converted or cleared for other land uses, the better sequestration can be].

Read more at:

  • https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions#agriculture
  • https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions#land-use-and-forestry 

 

Potential Targets For Agricultural & Related Emissions In The Future

  • Agriculture will need to reduce the equivalent of one giga tonne of carbon dioxide equivalents per year (GtCO2e/yr) in 2030 to meet the 2°C target.
  • [For the 2 degrees scenario] the reduction would need to increase after 2030, doubling to 2 GtCO2e/yr by 2050 and doubling again to 3-4 GtCO2e/yr by 2100.
  • This goal is for only non-carbon dioxide gases that cause direct emissions in agriculture: nitrous oxide, which comes from fertilizer; and methane, which comes principally from rice and livestock.
  • If we were to also consider CO2 reductions, the target would be even greater.

– theconversation.com

 

Sources

1. https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions

2. https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions#agriculture 

3. https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions#land-use-and-forestry 

4. https://www.bettermeetsreality.com/industries-sectors-that-emit-the-most-greenhouse-gases-carbon-dioxide/

5. https://ourworldindata.org/how-much-will-it-cost-to-mitigate-climate-change 

6. https://www.agric.wa.gov.au/climate-change/reducing-livestock-greenhouse-gas-emissions 

7. https://theconversation.com/why-we-need-better-ways-to-cut-greenhouse-gases-from-agriculture-59435

8. https://www.independent.co.uk/environment/rice-farming-climate-change-global-warming-india-nitrous-oxide-methane-a8531401.html

9. http://agriculture.vic.gov.au/agriculture/weather-and-climate/understanding-carbon-and-emissions/nitrogen-fertilisers

10. https://www.nap.edu/read/12883/chapter/5

11. https://en.wikipedia.org/wiki/Deforestation_and_climate_change

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