Extreme Rainstorms a New Texas Trend

"Scientists expect some parts of the United States to receive more precipitation as a result of global warming, while other parts receive less. But regardless of the trend in total precipitation, scientists predict that the rain and snow that does fall will be more likely to come in big downpours and heavy snowstorms," the group says.

Storms with heavy rainfall are now 28 percent more frequent in Texas than they were 60 years ago, the report found. And in the Dallas-Fort Worth area, storms with extreme precipitation increased in frequency by 42 percent from 1948 to 2006.

"At the rate we’re going, what was once the storm of the decade will soon seem like just another downpour," said Luke Metzger, director of Environment Texas.

Metzger pointed to the rainstorms that hit Texas in the summer as an illustration of what more extreme rainstorms could mean for the region. Flash floods and high water killed 59 people in Texas this summer and caused millions of dollars in damages to roads and buildings.

"More frequent downpours, fueled by global warming, will leave Texas even more vulnerable to dangerous flooding in years to come," said Metzger.

Workers clear debris from a creek in Marble Falls, Texas and replace a broken water line after record rainfall of 19 inches in one night. July 2, 2007 (Photo by Bob McMillan courtesy FEMA)

The new Environment Texas report, "When it Rains, It Pours: Global Warming and the Rising Frequency of Extreme Precipitation in the United States," examines trends in the frequency of large rain and snow events across the continental United States from 1948 to 2006.

Using data from 3,000 weather stations and a methodology originally developed by scientists at the National Climatic Data Center and the Illinois State Water Survey, the report identifies storms with the greatest 24-hour precipitation totals at each weather station, and analyzes when those storms occurred.

Nationally, the report shows that storms with extreme precipitation have increased in frequency by 24 percent across the continental United States since 1948.

At the state level, 40 states show a significant trend toward more frequent storms with extreme precipitation, while only one state, Oregon, shows a significant decline.

Dr. Radha Krishnan, an assistant professor at University of Texas-Dallas, said, "A vast majority of the climate scientists believe that carbon dioxide accumulation in the atmosphere due to human activities is causing irrevocable changes to the Earth's climate. If we reduce our energy consumption and therefore the release of CO2, we can begin to turn around the global warming that has been occurring since the last century."

CO2, or carbon dioxide, is emitted when coal, oil and gas are burned. It acts as a greenhouse, forming a layer in the atmosphere, trapping the Sun's heat close to the planet, and raising the planetary temperature.

"Given the now overwhelming evidence for the reality of global warming and the growing clarity of what is at stake for humanity and for all life on this planet if we still refuse to address the threat facing us, the time for action to be taken to prevent the worse consequences from climate change from happening is now," said Gary Stuard, executive director of the Interfaith Environmental Alliance.

"People of faith from the various religious traditions in Texas and around the world are calling upon ALL clergy and lay women and men, politicians, and business leaders to take on the moral leadership to courageously and selflessly address this pressing crisis," said Stuard.

Metzger was careful to note that an increase in the frequency of extreme rainstorms does not mean more water will be available in arid Texas. Scientists expect that, as global warming intensifies, longer periods of relative dryness will mark the periods between extreme rainstorms, increasing the risk of drought.

"How serious this problem gets is largely within our control," said Metzger, "but only if our country acts boldly to reduce the pollution that fuels global warming."

Copyright Environment News Service (ENS) 2007. All rights reserved.