A group of academics has attempted to estimate limits for biophysical processes to avoid catastrophic environmental changes. Jonhan Rockstrom and colleagues proposes the concept of “planetary boundaries”, a framework for quantifying safe thresholds for long-term human development. In a article published in the journal Nature, they suggest boundaries for nine indicators of stress to the Earth system: climate change, stratospheric ozone, land use change, freshwater use, biological diversity, ocean acidification, nitrogen and phosphorus inputs to the biosphere and oceans, aerosol loading and chemical pollution. [Read more →]