Planetary boundaries are a concept developed in 2009 by the team of international scientists led by Johan Rockström, then the director of the Stockholm Resilience Centre. The team defined nine quantitative planetary boundaries within which the planet and the human population can continue to thrive, yet their crossing could mean an abrupt environmental change and irreversible and potentially catastrophic damage to global natural and human systems.(1,2) The mutually interdependent planetary boundaries include: 1. Stratospheric ozone depletion, 2. Biodiversity loss and extinctions, 3. Chemical pollution and the release of novel entities, 4. Climate change, 5. Ocean acidification, 6. Freshwater consumption and the global hydrological cycle, 7. Land system change, 8. Nitrogen and phosphorus flows to the biosphere and oceans, and 9. Atmospheric aerosol loading.(2) Planetary boundaries scientists estimate that we have already crossed three of the boundaries – climate change, rate of biodiversity loss and global nitrogen cycle changes – which means that “planetary risks we’re facing are so large that business as usual is not an option”.(3) Since its conception, the planetary boundaries framework has become influential in international policymaking, including the formulation of the United Nations Sustainable Development Goals (SDG).(1-4)
PLANETARY BOUNDARIES
