Tuesday, May 10, 2011

Climate change could spawn more tornadoes

As with any major weather disaster these days -- from floods and hurricanes to wildfires and this week's tornado outbreak in the South -- people ask questions about its relation to the huge elephant that's lurking in the corner, global climate change.

Two separate studies in 2007 reported that global warming could bring a dramatic increase in the frequency of weather conditions that feed severe thunderstorms and tornadoes by the end of the 21st century.

One study, in the Proceedings of the National Academy of Sciences, found that locations could see as much as a 100% increase in the number of days that favor severe thunderstorms.

"The densely populated regions of the South and East, including New York City and Atlanta, could be especially hard-hit," reported study lead author Jeff Trapp of Purdue University.

The fuel for the more intense storms would be the predicted warming of the Earth caused by the burning of fossil fuels that release greenhouse gases.

Although the typically stormy spring could see more storms, "summer should have the highest increases in severe weather," said Trapp. His team reported that by the end of the century, the number of spring days with severe thunderstorm conditions would increase mostly over the Southern Plains and Florida.

But in the summer, almost the entire eastern half of the country might see an increase in days conducive to more severe storms, with the largest increases likely near the Gulf of Mexico and the Atlantic coast. (read more)