Pakistan is one area of the world that is experiencing early effects of what may be global warming. I don't think 10s of millions of people getting washed out is a trivial problem by any stretch.

They've dealt with resettlement in the IPCC papers. There are two general ways of handling GW - reduce emissions (dramatically) and adaptation. The idea of moving people is on the table, but it can't be seriously discussed, if the oil companies have convinced everyone that AGW is a fraud.

Like many problems, however, the expense and effects of this are exacerbated by waiting till the last minute to address them.