Increased flood risk in California under climate change

USGS researcher Mike Dettinger, whose paper on “atmospheric rivers” (ARs) and climate variability in California I highlighted over the weekend, has a new paper in the June Journal of the American Water Resources Association looking at how climate change might influence the phenomenon in the future. AR’s dominate California’s precipitation (and water supply) delivering a handful of huge bursts of moisture. Overall the averages don’t change that much in the climate change scenarios he modeled, but the extremes do:

Years with many AR episodes increase, ARs with higher-than-historical water-vapor transport rates increase, and AR storm-temperatures increase. Furthermore, the peak season within which most ARs occur is commonly projected to lengthen, extending the flood-hazard season. All of these tendencies could increase opportunities for both more frequent and more severe floods in California under projected climate changes.