California is in its fourth year of drought, which has left its water reserves dry and cost its economy billions of dollars. Imagine these conditions across southern and central U.S. for another 30 years. There's an 80 percent chance that 30-year droughts will be the new normal for the region after 2050, if we continue to burn through fossil fuels at the current rate, according to a NASA study published Thursday in the journal Science Advances. They expect higher temperatures will dry out the soil, increasing droughts. 

A megadrought of that length is like nothing the U.S. has experienced before. But there's still something we can do about it. NASA scientists note that the sooner we take action on greenhouse gas emissions, the better the chances are to avert a megadrought: NASA looked at what happens if greenhouse gas emissions start to come down worldwide by mid-century, and the risk of a megadrought drops to 60 percent.