Planetary Boundaries


As we have learned more about environmental science and the human impacts on the Earth, an international group of researchers developed the concept of planetary boundaries.  Nine processes and systems were identified that are responsible for regulating the stability and resilience of the earth system – the interactions of land, ocean, atmosphere and life that together provide conditions upon which our societies depend.

Nine planetary boundaries

  1. Climate change
  2. Change in biosphere integrity (biodiversity loss and species extinction)
  3. Stratospheric ozone depletion
  4. Ocean acidification
  5. Biogeochemical flows (phosphorus and nitrogen cycles)
  6. Land-system change (for example deforestation)
  7. Freshwater use
  8. Atmospheric aerosol loading (microscopic particles in the atmosphere that affect climate and living organisms)
  9. Introduction of novel entities (e.g. organic pollutants, radioactive materials, nanomaterials, and micro-plastics).

As the conditions for any of the systems degrade, they move further away from the center, green zone.  As shown in the diagram,  four of the boundaries have been crossed–climate change, biosphere integrity, land-system change, and biochemical flows have been crossed.

“Planetary boundaries do not dictate how human societies should develop but they can aid decision-makers by defining a safe operating space for humanity,” says co-author Katherine Richardson from the Center for Macroecology, Evolution and Climate at the University of Copenhagen.

“Managing these priorities at safe global levels will enable world development within a safe operating space on Earth, say the researchers.”

Quotations from  Earth Has Crossed Several ‘Planetary Boundaries,’ Thresholds of Human-Induced Environmental Changes   The latest findings will be presented at the World Economic Forum in Davos Jan. 21-24.

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