PrintMore Floods and Droughts
As noted above, there is a tendency for wet places to get wetter and dry places to get drier, with the subtropical dry zones expanding somewhat. When conditions are right to rain, warmer air holds more water (by roughly 7% per degree C or 4% per degree F), so all else equal, a warmer climate can deliver more rain in a hurry. But, evaporation speeds up with warming, too. All winter, Dr. Alley’s tomato patch is damp or frozen; in the summer, just a week or two after a downpour, he needs to water the plants again. A more summer-like world is likely to have more variability in the water cycle, with more floods and more droughts.
Video: Potential for Drought by the End of this Century (1:01)
Projections of drought by late in the century (2090-2099). To start the video, click on the image above. Although some places are expected to become wetter (check out Siberia), most of the world, especially where the population is not concentrated, is expected to experience increases in drought.
Click for a video transcript of "Potential for Drought by the End of this Century".
Credit: Dutton Institute(link is external). "EARTH 104 Module 5 Drought(link is external)." YouTube. January 23, 2015.