Didn't he amend this claim in a later article and now believes that we're headed for around a 3-3.5 degree heat increase, which won't render most of the earth uninhabitable? To be clear, I still think this is a terrifying number, which if it comes to pass will lead to the deaths of hundreds of millions of people, in particular in the developing world. I think we should do all that we can to bring the number down as much as possible.

[1] https://nymag.com/intelligencer/article/climate-change-after...