Agricultural Production under Climate Change: The Potential Impacts of Shifting Regional Water Balances in the United States

General circulation models predict significant and accelerating changes in local patterns of precipitation and temperature during the twenty-first century. Agriculture's vulnerability to climate change will depend on both the biophysical impacts of climate change on crop yields and on the agricultural system's ability to adapt to changing production conditions. Shifts in the extent and distribution of irrigated and dryland production are a potentially important adaptation response. Farmer flexibility to adapt may be limited, however, by changes in the availability of irrigation water under future climate conditions. This study uses a suite of models to explore the biophysical and economic impacts of climate change on U.S. fieldcrop production under several potential future climate projections, and to explore the potential limits and opportunities for adaptation arising from shifting regional water balances. The study findings suggest that, while irrigation shortages attributable to climate change have varying effects on cropland use, the aggregate impacts on national production are small relative to the direct biophysical impacts of climate change on yield.