NASA Projects Carbon Pollution Impact: ‘Some Regions Outside The Tropics May Have No Rainfall At All’

פורסם: 6 במאי 2013, 12:30 על ידי: Sustainability Org   [ עודכן 6 במאי 2013, 12:31 ]
By Climate Guest Blogger on May 3, 2013

In September, NOAA put together a video showing how climate change means wet areas get wetter and dry gets drier. Now NASA has a video of their own with similar findings.

Here is a screen-shot (NASA didn’t make the video embeddable):

Model simulations spanning 140 years [video here] show that warming from carbon dioxide will change the frequency that regions around the planet receive no rain (brown), moderate rain (tan), and very heavy rain (blue). The occurrence of no rain and heavy rain will increase, while moderate rainfall will decrease. Credit: NASA.

The summer precipitation varies year by year, of course, but as the snapshot above shows, by mid-century there is basically no rain in much of the Southwest and California some years. And the Amazon is not looking too good either (see also “NASA-Led Study Finds Warming-Driven Megadroughts Jeopardizing Amazon Forest“).

NASA’s news release explains

“In response to carbon dioxide-induced warming, the global water cycle undergoes a gigantic competition for moisture resulting in a global pattern of increased heavy rain, decreased moderate rain, and prolonged droughts in certain regions,” said William Lau of NASA’s Goddard Space Flight Center in Greenbelt, Md., and lead author of the study….

Areas projected to see the most significant increase in heavy rainfall are in the tropical zones around the equator, particularly in the Pacific Ocean and Asian monsoon regions.

Some regions outside the tropics may have no rainfall at all. The models also projected for every degree Fahrenheit of warming, the length of periods with no rain will increase globally by 2.6 percent. In the Northern Hemisphere, areas most likely to be affected include the deserts and arid regions of the southwest United States, Mexico, North Africa, the Middle East, Pakistan, and northwestern China. In the Southern Hemisphere, drought becomes more likely in South Africa, northwestern Australia, coastal Central America and northeastern Brazil.

“Large changes in moderate rainfall, as well as prolonged no-rain events, can have the most impact on society because they occur in regions where most people live,” Lau said.

This matches the findings of many other climate studies, including those on Dust-Bowlification: