July 12, 2012

Heat Waves More Common Due To Global Warming

Brett Smith for redOrbit.com - Your Universe Online

While a new study warned about the increasing odds of heat waves sweeping the earth, it also suggested the controversial nature and political undertones of climate studies.

The study, led by National Oceanographic and Atmospheric (NOAA) scientists and issued in coordination with the U.K. Met (Meterology) Office, said that global warming made the 2011 Texas heat waves from March through August 20 times as likely as they would have been in the 1960s. The report also noted that the unusually warm temperatures in the U.K. last November were 62 times as likely because of the forces of global warming.

Heat waves successively struck Texas last year from March to August, roasting the Lone Star State´s residents and straining the local agriculture.  According to researchers at Texas A&M University, the hot, dry weather cost the state $5.2 billion in lost revenue. Ranchers cattle stocks were also decimated, which led to the lowest official cattle count in 60 years at the beginning of 2012.

Oregon and Britain-based researchers involved in the NOAA study found that natural climate variability helped to set the stage for the heat wave in Texas. The weather in 2011 was heavily influenced by a year-long weather pattern called La Niña, an ocean-atmosphere phenomenon involving lower than normal sea surface temperatures.

After factoring in the influence of a La Niña year, the researchers found that the overall warming of the planet over the past 50 year made it about 20 times as likely that such a heat wave would occur.

While the scientific community attempts to explain the cause behind the crippling heat, many studies involving climate change typically take years to unfold. However, the latest study´s research involved only six events from 2011 and was published in about six months.

Some of the researchers tacitly admitted that given the nature of the work, these conclusions should be regarded as provisional.

This is hot new science,” study author and Oregon State University researcher Philip W. Mote told The New York Times. “It´s controversial. People are trying different methods of figuring out how much the odds may have shifted because of what we have put into the atmosphere.”

In addition to studying the Texas drought, researchers came to the general conclusion that much of the extreme weather being witnessed worldwide is consistent with what scientists expect on a warming planet. While an increase in the frequency of heat waves is to be expected, they also noted a strengthening of the water cycle, which translates to an increase in both droughts and monsoon rains.

The joint research team admits that the new study could be flawed, but should be used to spark a dialogue within the scientific community.

“While much work remains to be done in attribution science, to develop better observational datasets, to improve methodologies,” they wrote, “to make further progress in understanding and to assess and improve climate models, the contributions in this article demonstrate the potential that already exists for meaningful assessments of the connection between specific extreme weather or climate events that occurred in a particular year and climate change.”