A couple of years ago, George Monbiot wrote a column in the Guardian arguing with me. He was responding to an essay that I'd written arguing that there was no good evaluation of the potential climate impacts of a rapid build-out of renewable energies, and that it was possible that given the short time frame, that even if we were to actually get the political and social will to do so, we might cross critical tipping points in our attempt to save ourselves. Monbiot argued that this was indeed a real possibility, but that we had to try it anyway, since the stakes were so high. I responded…