Climate Change Threatens World’s Great Rivers, Study Says

Some of the world’s major rivers are drying up, with climate change being a major contributing factor, according to a new study by the National Center for Atmospheric Research. The problem is particularly acute in densely populated regions where communities depend on the rivers for food and water supplies, including those near the Niger in West Africa and the Ganges in South Asia, according to the study, which will be published next month in the American Meteorological Society’s Journal of Climate. “In the subtropics this is devastating, but the continent affected most is Africa,” said the center’s Kevin Trenberth. While researchers said direct human influence such as dam construction and the diversion of rivers for agriculture was a factor, that influence “is likely small” compared to changes in climate. The scientists looked at data and computer models of the flow of 925 rivers from 1948 to 2004, and found that about one-third of the rivers have been affected by climate change; of those, twice as many saw a decrease in flow as those that saw flow increase. Many of the rivers with increased flow are near the Arctic Ocean, where ice and snow is melting more rapidly than before, according to the report.