Planetary boundaries

Planetary boundaries refers to a concept developed by Johan Rockström (Stockholm Resilience Centre) and Will Steffen (Australian National University).^[1] It concerns a framework of boundaries or limits for environmental change, aimed at delineating a "safe operating space for humanity".^[1] The boundaries have been based on scientific research and show nine different Earth system processes that cannot be crossed without creating abrupt environmental change that may be irreversible.^[1] In the case of several boundaries, the points have already been crossed and we are close to crossing others.^[1]

The nine planetary boundaries are:^[2]

1. Stratospheric ozone depletion
2. Loss of biosphere integrity (biodiversity loss and extinction)
3. Chemical pollution and 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 phosphorous flows to the biosphere and oceans
9. Atmospheric aerosol loading

• http://www.stockholmresilience.org/research/planetary-boundaries.html - Stockholm Resilience Centre on the planetary boundaries
• http://www.stockholmresilience.org/research/planetary-boundaries/planetary-boundaries/about-the-research/the-nine-planetary-boundaries.html - the nine planetary boundaries
• http://www.ecologyandsociety.org/vol14/iss2/art32/ - the original article on planetary boundaries, published by Ecology and Society