[jyl]

I think people will handle this as we normally do. We’ll squabble and delay, deceive and divide, make money on the present, sell the future, until things are really, really bad, so bad that no-one can pretend it isn’t. Then those with money and resources and power will do what it takes to make their particular place livable, while those without will suffer and die. Then things will get worse, so that even the rich places aren’t livable and new plagues and pestilences sweep the world. Then, and only then, will we find a whole-planet solution. Which may be geo-engineering on a planetary scale. We’ll reduce solar radiation on the earth by orbiting shades in space or seeding the atmosphere with particles, extract carbon from the air and oceans, stuff that is science fiction today but will be reality fifty or a hundred years from today. Yes, we’ll also do lots and lots of renewable and nuclear and bioengineering and conservation - that won’t be enough by itself, but it will be enough that the geo-engineering can do the rest. By 2123, or 2223, a lot of species will be gone or nearly so, there may be fewer people, the rich may not be living in Aspen and Paris and Shanghai, the poor may be living more desperately and dying younger, but I think there will still be billions of people in organized, more or less affluent, technologically adept, culturally rich societies making music and babies and doing more than just surviving. Being in the US or one of the rich countries now probably gives decent odds that you, your kids, their kids, and so on to your descendants all live their lives in one of those fortunate societies. Being in one of the poor countries now probably gives decent odds of the opposite.