Tornado Outbreaks On The Rise: Is Climate Change Cause For Blame?

- Frequent tornadoes and thunderstorms that kill people and destroy property have become a matter of grave concern. In the United States alone, the insured losses caused by severe thunderstorms have been put at $8.5 billion from the period between January to June 2016.

A new study has tried a linkage between climate change and the increasing incidents of tornadoes. Calling for a deeper study on some meteorological factors, the paper zeroes in on vertical wind shear as an important variable in triggering mega storms.

Led by Michael Tippett, associate professor of applied physics at Columbia Engineering, the study published in Science scans significant tornadoes and outbreaks lasting for many days. It notes that major tornado incidents had been going up substantially since 1954 though a definite reason could not be given for that.

In the paper, researchers have analyzed the trends in the tornado outbreaks and found extreme outbreaks are increasing at the fastest rate.

"This study raises new questions about what climate change will do to severe thunderstorms and what is responsible for recent trends," says Tippett, who is also associated with the Data Science Institute and the Columbia Initiative on Extreme Weather and Climate.

Offering new insight into the trends in environmental conditions that encourage thunderstorms and tornadoes, the study looks at the convective available potential energy, or CAPE, and storm relative helicity, a measure of vertical wind shear.

With greenhouse gases trapping more energy and heat in the atmosphere air will start holding more water and that opens the scope for extreme storms.

One crucial ingredient in forming violent storms is vertical wind shear, which lifts intensity in sync with altitude. Unlike CAPE, shear does not change much with global warming. (FullText)