Sorry guys, sorting out climate change is just the start. Their success in influencing climate change policy (if not practice) seems to have emboldened earth system scientists to initiate a wider debate about the earth’s limits. A recent issue of Nature journal tries to establish the ecological ‘operating space’ for humans, and could spark off some pretty interesting debates over the coming months.
‘We have tried to identify the Earth-system processes and associated
The inner green shading represents the proposed safe operating space for nine planetary systems. The red wedges represent an estimate of the current position for each variable. The boundaries in three systems (rate of biodiversity loss, climate change and human interference with the nitrogen cycle), have already been exceeded
thresholds which, if crossed, could generate unacceptable environmental change. We have found nine such processes for which we believe it is necessary to define planetary boundaries: climate change; rate of biodiversity loss (terrestrial and marine); interference with the nitrogen and phosphorus cycles; stratospheric ozone depletion; ocean acidification; global freshwater use; change in land use; chemical pollution; and atmospheric aerosol loading (see Fig. 1 and Table).
Their conclusion? ‘Humanity may soon be approaching the boundaries for global freshwater use, change in land use, ocean acidification and interference with the global phosphorous cycle. Our analysis suggests that three of the Earth-system processes — climate change, rate of biodiversity loss and interference with the nitrogen cycle — have already transgressed their boundaries.’
Oops.
[h/t Steve Jennings]