New Report: Extreme Downpours Up 28 Percent in Texas

DALLAS—Scientists have said for years that global warming was “loading the dice” when it comes to increasing the frequency of severe storms, and a new Environment Texas report makes it clear that Texas is already experiencing extreme downpours much more frequently.  Specifically, the new report found that storms with heavy rainfall are now 28 percent more frequent in Texas than they were 60 years ago.

“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 this summer as an illustration of what more extreme rainstorms could mean for the region.  Flash floods and high water killed 59 people in Texas 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.

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. 

Key findings for Texas and DFW include:

• Texas experienced a 28 percent increase in extreme rainstorms during the period studied.

• Storms with extreme precipitation increased in frequency by 42 percent in the DFW Metroplex from 1948 to 2006. 

These findings are consistent with the predicted impacts of global warming.  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. 

Dr. Radha Krishnan, an Assistant Professor at UT Dallas said “anthropogenic global warming is a scientific consensus at this point. 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 (which is obtained primarily from fossil fuels currently) consumption and therefore the release of CO2, we can begin to turn around the global warming that has been occurring since the last century.”

“Given the now over-whelming 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.” 

Metzger was careful to note that an increase in the frequency of extreme rainstorms does not mean more water will be available.  Scientists expect that, as global warming intensifies, longer periods of relative dryness will mark the periods between extreme rainstorms, increasing the risk of drought.  For example, the Intergovernmental Panel on Climate Change (IPCC) predicts that, under a scenario of intense warming, the percent of land enduring severe drought globally could be 30 times greater by the end of the century than it is today.

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

According to the most recent science, the United States must reduce its total global warming emissions by at least 15 percent by 2020 and by at least 80 percent by 2050 in order to prevent the worst effects of global warming. 

“Steep reductions in global warming pollution are challenging but achievable,” noted Metzger, “and we already have the energy efficiency and renewable energy technologies we need to get started.”

“We applaud Representative Eddie Bernice Johnson for backing the Safe Climate Act—the only legislation in Congress that would reduce pollution fast enough to protect future generations from the worst effects of global warming. We also urge her to speak out in favor of strengthening the “Lieberman-Warner Climate Security Act of 2007,” concluded Metzger.