Cook et al. 2015
, T.R. Ault, and J.E. Smerdon, 2015: Unprecedented 21st-century drought risk in the American Southwest and Central Plains. Sci. Adv., 1, no. 1, e1400082, doi:10.1126/sciadv.1400082.
In the Southwest and Central Plains of Western North America, climate change is expected to increase drought severity in the coming decades. These regions nevertheless experienced extended Medieval-era droughts that were more persistent than any historical event, providing crucial targets in the paleoclimate record for benchmarking the severity of future drought risks. Here, we use an empirical drought reconstruction and three soil moisture metrics from 17 state-of-the-art general circulation models (GCMs) to show that these mod- els project a significantly drier later half of the 21st-century compared to the 20th-century and earlier paleoclimatic intervals. This desiccation is consistent across the majority of models regardless of the employed moisture balance variable, indicating a coherent and robust drying response to warming despite the diversity of models and metrics analyzed. Notably, future drought risk will likely exceed even the driest centuries of the Medieval Climate Anomaly (1100-1300 CE) in both moderate (RCP 4.5) and high (RCP 8.5) future emissions scenarios, leading to drought conditions without precedent during the last millennium.