(Environmental) Planetary Boundaries: What They Are, & Why It Could Be Dangerous To Cross Them

(Environmental) Planetary Boundaries: What They Are, & Why It Could Be Dangerous To Cross Them

Resource depletion is a legitimate concern some have for the future of the human race.

Environmental degradation is obviously not good if we want to keep a sustainable supply of natural resources.

A scientific team has identified nine planetary boundaries, that if crossed, could have severe consequences for our planet and natural resource supply into the future.

This is a short guide summarising those planetary boundaries – what they are, and why it could be dangerous for us to cross them.

 

Summary – Which Boundaries Have We Already Crossed To Unsafe Levels?

The following 3 are in the high risk range already:

  • Biosphere Integrity, genetic diversity
  • Biogeochemical flows, nitrogen
  • Biogeochemical flows, phosphorus

Land system change, and also climate change, are both in the increasing risk range.

 

What Are Planetary Boundaries?

They are part of a concept.

  • The boundaries present a set of nine planetary boundaries within which humanity can continue to develop and thrive for generations to come
  • … these boundaries regulate the stability and resilience of the Earth system
  • Crossing these boundaries increases the risk of generating large-scale abrupt or irreversible environmental changes

– stockholmresilience.org

 

What Are The 9 Different Planetary Boundaries? 

  • Climate Change – release of greenhouse gases like CO2 into the atmosphere, leading to Earth’s warming.
  • Release of Novel Entities – Emissions of toxic and long-lived substances such as synthetic organic pollutants, heavy metal compounds and radioactive materials.
  • Stratospheric Ozone Depletion – filters out ultraviolet (UV) radiation from the sun. It’s not desirable for the ozone to be depleting.
  • Atmospheric Aerosol Loading – aerosols have an impact on the Earth’s climate system.
  • Ocean Acidification – CO2 emissions are absorbed by the ocean, leading to warming, altering of the ocean’s chemistry and decreasing the pH of the surface water (amongst other impacts).
  • Biogeochemical Flows – the flow of Nitrogen & Phosphorus into the biosphere and oceans. This occurs heavily as a result of agriculture and industrial activity.
  • Freshwater Use – human consumption of freshwater and drinking water, and the impact of climate change on the natural hydrological cycle.
  • Land-System Change – the change in use of land, such as forests, grasslands, wetlands and other vegetation types that have primarily been converted to agricultural land. There’s many negative impacts to this.
  • Biosphere Integrity – Functional Diversity, & Genetic Diversity. Involves loss of biodiversity, and also extinction. Biodiversity loss is the extinction of species (plant or animal) worldwide, and also the local reduction or loss of species in a certain habitat.

 

How Are We Tracking With Planetary Boundary?

The tracking labels for each boundary can be categorised into:

  • Below boundary (safe)
  • In the zone of uncertainty (increasing risk)
  • Beyond the zone of uncertainty (high risk)

As of 2015, the boundaries fitted into these categories:

  • Climate Change – in the zone of uncertainty (increasing risk)
  • Release Of Novel Entities – no global quantification
  • Stratospheric Ozone Depletion – below boundary (safe)
  • Atmospheric Aerosol Loading – no global quantification
  • Ocean Acidification – below boundary (safe)
  • Biogeochemical Flows – Nitrogen is beyond the zone of uncertainty (high risk), & Phosphorus is also beyond the zone of uncertainty (high risk)
  • Freshwater Use – below boundary (safe)
  • Land-System Change – in the zone of uncertainty (increasing risk)
  • Biosphere Integrity – Functional Diversity has no global quantification, & Genetic Diversity is beyond the zone of uncertainty (high risk)

 

Sources

1. https://www.stockholmresilience.org/research/planetary-boundaries/planetary-boundaries/about-the-research/the-nine-planetary-boundaries.html

2. https://undark.org/article/ted-nordhaus-carrying-capacity-ecology/ 

3. https://www.stockholmresilience.org/research/planetary-boundaries/planetary-boundaries/about-the-research.html

4. https://www.stockholmresilience.org/research/planetary-boundaries.html

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