Climate change threatens to turn the planet into a stormy, overheated mess: That much we know. But according to 28 leading scientists, greenhouse gas pollution is but one of nine environmental factors critical to humanity’s future. If their boundaries are stretched too far, Earth’s environment could be catastrophically altered — and three have already been broken, with several others soon to follow.
This grim diagnosis, published Wednesday in Nature, is the most ambitious assessment of planetary health to date. It’s a first-draft users’ manual for an era that scientists dub the “anthropocene,” in which nearly seven billion resource-hungry humans have come to dominate ecological change on Earth. The scientists’ quantifications are open to argument, but not the necessity of their perspective.
“It’s a crude attempt to map the environmental space in which we can operate,” said Jon Foley, director of the University of Minnesota’s Institute on the Environment and one of the paper’s lead authors. “We need to keep our activities in a certain range, or the planet could tip into a state we haven’t seen in the history of our civilization.”