Drying in US West to Get Much Worse (image) The Earth Institute at Columbia University Share Print E-Mail Caption A representation of the summer moisture in the US Central Plains and Southwest is shown. The brown line represents the variation in dryness since the year 1000; the lower the line on the graph, the drier the conditions. Colored lines to the right side of the graph represent what climate models see ahead: a trend toward dryness not seen in the previous millennium. As the authors describe it: Regional average time series of the summer season moisture balance metrics from the NADA and CMIP5models.The observational NADA PDSI series (brown) is smoothed using a 50-year loess spline to emphasize the low-frequency variability in the paleo-record. Model time series (PDSI, SM-30cm, and SM-2m) are the multimodel means averaged across the 17 CMIP5models, and the gray shaded area is the multimodel interquartile range for model PDSI. Credit Cook et al., Science Advances, 2015 Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.