The Nature Conservancy has released a projection of business-as-usual climate impacts, which shows particularly heavy impacts in Kansas, Nebraska, and Iowa. The predictions are fairly grim.
The analysis is based on averaging model results for IPCC Scenarios B1 assumes a (decrease in emission rates over the next century for a total concentration of 538ppm by 2100) Scenario A1B (gradual leveling off of emission rates for a total concentration of 711ppm); and scenario A2 (increase in emission rates for concentrations of 857ppm by 2100.) The climate models aren’t great so far on regional and sub-regional scales, although I hear that there have already been improvements since the last IPCC report. At present, these estimates are probably the best possible (and temperature predictions are more solid than precip.) They’re as likely to be too low as too high, so the uncertainties aren’t much comfort.
Not that this is likely to make much difference. Conditions in 2100 or even 2050 won’t hurt today’s voters, and of course today’s politicians won’t be running for office by the time the excrement hits the rotary air machine.