The Uninhabitable Earth: Life After Warming

by David Wallace-Wells

if a best-case scenario is now somewhere north of 2 degrees of warming by 2100, it seems that the likeliest outcome, the fattest part of the bell curve of probability, sits between 2.5 and 3 degrees, or just a bit above. Probably even that amount of warming would require significant negative-emissions use, given that our use of carbon is still growing. And there is also some risk from scientific uncertainty, the possibility that we are underestimating the effects of those feedback loops in natural systems we only poorly understand. Conceivably, if those processes are triggered, we could hit 4 degrees of warming by 2100, even with a meaningful reduction in emissions over the coming decades. But the track record since Kyoto implies that human shortsightedness makes it unproductive to offer predictions about what will happen, when it comes to emissions and warming; better to consider what could happen. The sky is literally the limit.