By Tom Abel
Some years ago now a team of Swedish scientists proposed an interesting framework for understanding planetary environmental problems. It generated a range of responses from the environmental community, mostly positive. I had what is undoubtedly a very unusual response to their framework, and while it is perhaps old news, it may still be useful to present it here. As an anthropologist, I see planetary problems from a cultural and evolutionary perspective that could offer a different take on the subject.
First, though, I want to say that the identification of the nine interrelated environmental ‘boundaries’ has been unquestionably of great value (Planetary Boundaries). Raising awareness about the problems and emphasizing nonlinear feedbacks effects, and so the possible triggering of abrupt global environmental changes, are integral to a more sophisticated discussion of climate change and the other problems they highlight. To list them, they are climate change, ocean acidification, ozone depletion, nutrient fluxes, global freshwater use, land use change, biodiversity loss, aerosol loading, and chemical pollution.
The nine ‘boundaries’ are concisely represented in their popular diagram. The green space in the center represents the safe operating values. If the wedge exceeds the green space then it has already crossed its threshold and become a threat of flipping to a disastrous state for our human presence on the planet. Worse, the problems are interrelated and interactions are a grave threat. As an example of dangerous interactions, loss of soil moisture, degradation of land to new land types, and biodiversity loss all reduce the ability of ecosystems to sequester CO2, and thus increase greenhouse effects.
These same issues can be found today in a number of diagrams such as the one above. The Swedish authors have called our times the ‘great acceleration’, a time of rapid growth of a number of environmental problems. They have argued persuasively that now is the time that we need to ‘bend the curves’.