Climate models predict longer and more severe droughts by the end of the century.
Drought has stricken much of the U.S. Southwest and Central Plains in recent years. But scientists now believe future droughts in the last half of this century could be the worst in the past millennium. Computer model projections of soil moisture show increases in human-produced greenhouse gas emissions are driving up the risk of megadroughts, droughts lasting more than 30 years. A team of researchers led by scientists at NASA’s Goddard Institute for Space Studies analyzed model results from two climate scenarios: a moderate scenario where greenhouse gas emissions stop increasing by the year 2050, and a high scenario where emissions continue to rise at their current rate through 2100. In both cases the team found conditions in the western United States are drier and the risk of decades-long drought increases. Watch the videos to see computer simulations that show how soil conditions in North America change under each emissions scenario.