Global Warming and Floods

http://www.nwf.org/Wildlife/Threats-to-Wildlife/Global-Warming/Global-Warming-is-Causing-Extreme-Weather/Floods.aspx

If it seems like the United States is getting more heavy storms and major floods these days, it's because we are. Global warming is partly to blame for these heavy rainfall events. Because warmer air can hold more moisture, heavier precipitation is expected in the years to come.

In the Midwest and Northeast, big storms that historically would only be seen once every 20 years are projected to happen as much as every 4 to 6 years by the end of the 21st century. At the same time, shifts in snowfall patterns, the onset of spring, and river-ice melting may all exacerbate flooding risks.

•••••

Recent decades have brought more heavy summer rainfall events along with increased likelihood of devastating floods. While no single storm or flood can be attributed directly to global warming, changing climate conditions are at least partly responsible for past trends. Because warmer air can hold more moisture, global warming is expected to bring more and heavier precipitation in the years to come.

Global warming is already causing days with heavy rain, and in some cases, extreme amounts of rain, to increase. Heavy rains flush pollution, sediment, and nutrients into the waters upon which we depend. Nutrients in excess can lead to “dead zones” of depleted oxygen within lakes and waterways.

•••••