Deadly tornadoes slam through six states

More powerful, destructive, and deadlier storms will be the “new normal” as the effects of climate change take root, the top U.S. emergency management official said after massive tornadoes ravaged six states.

Meteorologists and other scientists have long warned of the growing intensity of weather events like storms, fires and flooding.

But the crisis hit the U.S. in a terrifying way when more than two dozen twisters raked across large swaths of the American heartland, leaving more than 90 people dead, dozens missing and communities in ruin.

“This is going to be our new normal,” Deanne Criswell, head of the Federal Emergency Management Agency, told CNN’S “State of the Union.” “The effects that we’re seeing from climate change are the crisis of our generation,” she added. Criswell warned of the challenge that the United States faces in addressing such severe weather events.

In another programme, she told ABC’s “This Week,” “We’re seeing more intense storms, severe weather, whether it’s hurricanes, tornadoes, wildfires. The focus I’m going to have is, how do we start to reduce the impacts of these events.” The tornado that reduced several towns to rubble was a gargantuan twister. It rumbled along the ground for over 320 km, one of the longest, if not the longest on record.

What causes a tornado?

Tornadoes are whirling, vertical air columns that form from thunderstorms and stretch to the ground. They travel with ferocious speed and lay waste to everything in their path. Thunderstorms occur when denser, drier cold air is pushed over warmer, humid air, conditions scientists call atmospheric instability. As that happens, an updraft is created when the warm air rises. When winds vary in speed or direction at different altitudes- a condition known as wind shear-the updraft will start to spin. These changes in winds produce the spin necessary for a tornado. For especially strong tornadoes, changes are needed in both the wind’s speed and direction.

Role of climate change

Scientists say figuring out how climate change is affecting the frequency of tornadoes is complicated. But they do say the atmospheric conditions that give rise to such outbreaks are intensifying in the winter as the planet warms. One paper published recently by scientific association AGU says its analysis “suggests increasing global temperature will affect the occurrence of conditions favourable to severe weather.”

Rising global temperatures are driving significant changes for seasons that we traditionally think of as rarely producing severe weather. Stronger increases in warm humid air in fall, winter, and early spring mean there will be more days with favourable severe thunderstorm environments – and when these storms occur, they have the potential for greater intensity. Projections suggest that stronger, tornado-producing storms may be more likely as global temperatures rise, though strengthened less than we might expect from the increase in available energy. Studies have shown that the rate of increase in severe storm environments will be greater in the Northern Hemisphere, and that it increases more at higher latitudes.

Picture Credit : Google

Leave a Reply

Your email address will not be published. Required fields are marked *