A drought is an extended period of dry weather caused by a lack of rain or snow. As temperatures rise due to global climate change, more moisture evaporates from land and water, leaving less water behind. Some places are getting more rain or snow to make up for it, but other places are getting less.
What's happening now?
Since the 1970s, droughts have become longer and more extreme worldwide, particularly in the tropics and subtropics.
What will happen in the future?
Droughts are expected to keep getting longer and more severe. The U.S. Southwest is at particular risk for increasing droughts.
Why does it matter?
A drought means there's less water available for drinking, watering crops, making electricity at hydroelectric dams, and other uses. For example, an ongoing drought in the U.S. Southwest is straining water supplies in states like Nevada and Arizona, where water is already scarce.
Check out the major effects of droughts on people and the environment: