Malaria still existed throughout much of the US in the 1930s/40s. Since then it has gotten much warmer throughout the US. But malaria is basically gone now. Why? Rising incomes.
So the point on global warming is, it'll create real problems wherever states and societies don't have the money to deal with the challenges - such as insect migration.
Now take a look at this chart from the WSJ and realize what happens when incomes fall - and how quickly.
Recently, Wikistrat ran a sim where we discussed the possibility of states making sovereign land sales. Several analysts said that, while that happened in previous centuries (note how most of America was acquired), nobody would consider that now.
My comeback was, if the financial situation gets bad enough, countries will sell just like people get rid of an underwater house.
Greece is looking pretty bad, and I think it's a harbinger of massive debt issues to come for a demographically aging West.
The discussion we had was about the Arctic and the possibility of some Arctic Council members selling out to non-members so as to tap the finance needed for exploitation of opportunities. After all, the US bought its seat at the table - aka, Alaska.