Four of nine planetary boundaries now crossed
▻http://www.pierrejoris.com/blog/?p=12737
Four of nine planetary boundaries have now been crossed as a result of human activity, says an international team of 18 researchers in the journal Science. The four are: climate change, loss of biosphere integrity, land-system change, altered biogeochemical cycles. The scientists say that two of these, climate change and biosphere integrity, are “core boundaries” – significantly altering either of these would “drive the Earth System into a new state”. The team will present their findings in seven seminars at the World Economic Forum in Davos (21-25 January).
L’article de Science (le résumé, le reste derrière #paywall)
Planetary boundaries : Guiding human development on a changing planet
▻http://www.sciencemag.org/content/early/2015/01/14/science.1259855
The planetary boundaries framework defines a safe operating space for humanity based on the intrinsic biophysical processes that regulate the stability of the Earth System. Here, we revise and update the planetary boundaries framework, with a focus on the underpinning biophysical science, based on targeted input from expert research communities and on more general scientific advances over the past 5 years. Several of the boundaries now have a two-tier approach, reflecting the importance of cross-scale interactions and the regional-level heterogeneity of the processes that underpin the boundaries. Two core boundaries—climate change and biosphere integrity—have been identified, each of which has the potential on its own to drive the Earth System into a new state should they be substantially and persistently transgressed.