Large differences among global models (e.g.,
annual precipitation produced by ECHAM vs. MIROC models for the central US
as shown in Figure 7) allow for a wide variety of future precipitation regimes in
major grain-producing regions. This report did not examine climate trends for the
latter half of the 21st century. However, Walthall et al. (2012) report that
temperature trends by mid century are projected to continue through 2100 unless
effective mitigation measures are instituted soon