Earth Abides. The major effect of global warming will be to wreck the worlds industrial and advanced economies (we are no longer "industrial"). They are the cause of the warming in the first place. So if we do nothing, the problem will eventually take care of itself.

The only nations that will survive are those with existing predominant village-based agricultural economies; Central America, India, Brazil, S. East Asia, Tropical Africa, etc. (Providing their agriculture can adapt to the new conditions.)

I guess the Conservatives will be proven right after all: "Market forces will force us to adapt." There's nothing like mass starvation, war, and economic and social collapse to encourage a change in your business model.