Quantcast
Environmental News for a Healthier Planet and Life

Tornados Attacking in Swarms. Is Climate Change to Blame?

Climate
Tornados Attacking in Swarms. Is Climate Change to Blame?

Tornados are among the most frightening storms, in part because of their destructive power but also because of their unpredictability. You can track and prepare for a hurricane, but tornados strike quickly and with little warning. And unlike hurricanes, tornados have no specific season.

The destructive power of tornados makes them especially fearsome.
Photo credit: Shutterstock

And if it seems to you that tornado incidents have been bigger and scarier recently, you're right, says a team of researchers in a new study published today in Science. While it found that tornados haven't increased in number and, in fact, the number of days on which tornados are occurring has decreased, the appearance of tornados in clusters has risen. That means if one tornado touches down, more are likely to occur in quick succession in the same geographic area. And scientists are asking if climate change is to blame.

"When people ask, 'Are we getting more tornadoes, are we getting fewer tornadoes, are they later, are they earlier?'—the answer to everything is yes," said lead study author Harold Brooks, senior scientist at the National Oceanic and Atmospheric Administration's Severe Storms Laboratory in Norman, Oklahoma.

An earlier study by Florida State University professor James Elsner, released in August, found a similar change in tornado patterns.

"We may be less threatened by tornadoes on a day-to-day basis, but when they do come, they come like there's no tomorrow," said Elsner.

The new study found that while the number of days with tornados stronger than F-1 on the Fujita scale for ranking tornado power decreased, the odds of having a day with 32 tornados has doubled. Prior to 1990, most years had no such days. Since 2001, every year has had one day with 32 or more tornados. A three-day period in April 2011 produced 355 tornados across the southern and eastern U.S. with 211 touching down in a 24-hour period on April 27, primarily in Alabama and Mississippi, killing more than 300 people in six states.

The study's summary says, "Whether or not climate change has had an impact on the occurrence of tornadoes in the United States has become a question of high public and scientific interest, but changes in how tornadoes are reported have made it difficult to answer it convincingly. We show that, excluding the weakest tornadoes, the mean annual number of tornadoes has remained relatively constant, but their variability of occurrence has increased since the 1970s. This is due to a decrease in the number of days per year with tornadoes combined with an increase in days with many tornadoes, leading to greater variability on annual and monthly time scales and changes in the timing of the start of the tornado season."

Single tornados are terrifying enough, but now clusters are becoming more common.
Photo credit: Shutterstock

While the study only hinted a link to climate change, Brooks said it's a preliminary step in investigating how global warming might be connected to changes in the patterns of tornado activity. Brooks told Live Science "Obviously, we've had a change in the frequency of the number of days of tornadoes, and in some sense that's a reflection of the climate being different than it was. But we don't have the primary cause and effect yet."

Tornados develop when warm, moist weather fuels thunderstorms that create changing wind directions (wind shear) that rotates the winds. While global warming creates fertile conditions for thunderstorms, studies have disagreed on whether it strengthens or weakens wind shear.

YOU MAY ALSO LIKE

Hawaii Hurricanes, El Niño and Climate Change

Obama Plan Helps Communities Prepare for Extreme Weather Brought on by Climate Change

Scientists Find Extreme Weather Events Fueled by Climate Change

A technician inspects a bitcoin mining operation at Bitfarms in Saint Hyacinthe, Quebec on March 19, 2018. LARS HAGBERG / AFP via Getty Images

As bitcoin's fortunes and prominence rise, so do concerns about its environmental impact.

Read More Show Less

EcoWatch Daily Newsletter

OR-93 traveled hundreds of miles from Oregon to California. Austin Smith Jr. / Confederated Tribes of Warm Springs / California Department of Fish and Wildlife

An Oregon-born wolf named OR-93 has sparked conservation hopes with a historic journey into California.

Read More Show Less

Trending

A plume of exhaust extends from the Mitchell Power Station, a coal-fired power plant built along the Monongahela River, 20 miles southwest of Pittsburgh, on Sept. 24, 2013 in New Eagle, Pennsylvania. The plant, owned by FirstEnergy, was retired the following month. Jeff Swensen / Getty Images

By David Drake and Jeffrey York

The Research Brief is a short take about interesting academic work.

The Big Idea

People often point to plunging natural gas prices as the reason U.S. coal-fired power plants have been shutting down at a faster pace in recent years. However, new research shows two other forces had a much larger effect: federal regulation and a well-funded activist campaign that launched in 2011 with the goal of ending coal power.

Read More Show Less
LumiNola / E+ / Getty Images

By Gwen Ranniger

Fertility issues are on the rise, and new literature points to ways that your environment may be part of the problem. We've rounded up some changes you can make in your life to promote a healthy reproductive system.

Read More Show Less
Seattle-based Community Loaves uses home bakers to help those facing food insecurity during the pandemic. Sol de Zuasnabar Brebbia / Getty Images

By Lynn Freehill-Maye

The irony hit Katherine Kehrli, the associate dean of Seattle Culinary Academy, when one of the COVID-19 pandemic's successive waves of closures flattened restaurants: Many of her culinary students were themselves food insecure. She saw cooks, bakers, and chefs-in-training lose the often-multiple jobs that they needed simply to eat.

Read More Show Less