"...does anyone have any idea of just how warm and dry a previously inhospitable climate may become?

Well, the scientific models do not support the idea the Earth will become dry and inhospitable at all. The increase in temeperature will be modest, less the 2 degrees F, and will be mostly due to a rise in the minimum temperature. This will produce an increase in H2O evaporation > increase in humidity > increase in rainfall > increase in plant growth and crop yield > increase in O2 production, an integral part of plant photosynthesis. Yes, a limited amount of global warming is the best thing we can hope for to counter the outrageous population growth in the Third World.