I thought it was Even Steven ? My life has been a lie ! <| sep |> Good observation , thanks . I have not studied his essay , but I am familiar with many of the feedbacks he discusses . I ' ve watched a few of his presentations on video , as I understand it his basic premise is Our greenhouse gas forcing has triggered a number of positive or selfreinforcing feedbacks which are overwhelming the negative or selflimiting feedbacks and thus causing accelerating changes to our climate that are now effectively beyond our control . This ties in with the exponential function , unrestrained positive feedbacks naturally lead to exponential behavior , and has led some people to fear that we may have passed some sort of invisible tipping point beyond which the climate runs away and global temperatures rise very quickly over a relatively short period of time . There is also the matter of global dimming , short lived aerosols in the atmosphere from industrial activity that are thought to have a short term cooling effect on the climate . This periodically happens quite naturally from volcanic eruptions , but remove our ongoing industrial activity , say due to global economic collapse , and once again you could see temperatures rise very quickly over a relatively short period of time . There are other dynamics at play , and I have found that McPherson generally does a pretty good job of staying on top of the latest info , but the leap to near term extinction is where he loses a lot of people . Correct me if I ' m wrong , but I think his whole argument boils down to humans have not evolved on a planet that is 3 deg C above preindustrial baselineThe reasoning being that we are , after all , just another species of mammal . A very clever and adaptive species of mammal , but that probably won ' t help us when the majority of the globe essentially becomes uninhabitable for humans , uninhabitable for our crops , and uninhabitable for our domesticated animals . In a time frame that could be as short as a few decades . People can split hairs about extinction , go right ahead , but I don ' t think anyone who has a reasonable grasp of the facts will argue that we , as in the entire species , are headed for an epic evolutionary bottleneck of biblical proportions .