A rash of flash floods has struck the US during this spring: Rhode Island, Tennessee, Arkansas, and most recently Oklahoma have all faced devastating floods that have resulted in the loss of property and in some cases tragic deaths. While flash floods have occurred throughout US history, the number of big floods this year appears abnormal at best, but not unexpected by researchers. Climatologists warned last year that an increase in floods and severe storms is very probable as the world warms.
A US report commissioned by the Bush Administration in 2007 and released in 2009 warned that the United States would see greater incidences of severe weather and heavier rainfall. The report, which looked at the US regionally, predicted that more precipitation in winter and spring in the Midwest would lead to increased flooding. In addition, the report predicted increases in flooding and severe weather for the Southeast. The report stated that "the amount of rain falling in the heaviest downpours has increased approximately 20 percent on average in the past century, and this trend is very likely to continue, with the largest increases in the wettest places."
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In a recent interview with climate blogger Joe Romm, Dr. Kevin Trenberth, head of the Climate Analysis Section at the National Center for Atmospheric Research, said that both the media and scientists were downplaying the well-established link between climate change and these floods. "I find it systematically tends to get underplayed
and it often gets underplayed by my fellow scientists," Trenberth says. "Because one of the opening statements, which I’m sure you’ve probably heard is 'Well you can’t attribute a single event to climate change.' But there is a systematic influence on all of these weather events now-a-days because of the fact that there is this extra water vapor lurking around in the atmosphere than there used to be say 30 years ago. It’s about a 4 percent extra amount, it invigorates the storms, it provides plenty of moisture for these storms and it’s unfortunate that the public is not associating these with the fact that this is one manifestation of climate change. And the prospects are that these kinds of things will only get bigger and worse in the future."
For his part, Romm has recently suggested that the media—which has almost completely ignored the scientific connection between climate change and these floods—start referring to weather patterns clearly linked by data to climate change as 'global-warming type events'.
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http://news.mongabay.com/2010/0616-hance_freakfloods.html