Nine planetary boundaries (the crucial processes)
- Climate change
- Change in biosphere integrity (biodiversity loss and species extinction)
- Stratospheric ozone depletion
- Ocean acidification
- Biogeochemical flows (phosphorus and nitrogen cycles)
- Land-system change (for example deforestation)
- Freshwater use
- Atmospheric aerosol loading (microscopic particles in the atmosphere that affect climate and living organisms)
- Introduction of novel entities (e.g. organic pollutants, radioactive materials, nanomaterials, and micro-plastics). Journal Reference:
- Will Steffen, Katherine Richardson, Johan Rockström, Sarah E. Cornell, Ingo Fetzer, Elena M. Bennett, R. Biggs, Stephen R. Carpenter, Wim de Vries, Cynthia A. de Wit, Carl Folke, Dieter Gerten, Jens Heinke, Georgina M. Mace, Linn M. Persson, Veerabhadran Ramanathan, B. Reyers, and Sverker Sörlin. Planetary boundaries: Guiding human development on a changing planet. Science, 15 January 2015 DOI: 10.1126/science.1259855
Source: McGill University. “Nearly half the systems crucial to stability of planet compromised.” ScienceDaily. ScienceDaily, 15 January 2015. <www.sciencedaily.com/releases/2015/01/150115163533.htm>.