Pittsburgh Post-Gazette

Tornados will get worse, and they’re coming our way Tornados can find you

- Mark Gongloff is a Bloomberg Opinion editor and columnist.

If the Car Crash Fairy offered you a deal that would lower your odds of getting in a car accident, but an accident would be far more likely to injure or kill you, you probably wouldn’t take that deal. That might be the bargain we have made with climate change and two of the most destructiv­e natural disasters.

Many of the heat waves, droughts and floods wracking the planet have clearly been made more likely by warming. The jury is still out on whether tornadoes and hurricanes will similarly become more frequent. They might even happen less often, at least in some places.

But the ones that do occur could be more destructiv­e, raising risks for everyone from insurers to urban planners.

Some places better, some places worse

People in the Midwest facing yet another onslaught of tornadoes could be forgiven for thinking there have never been more of them. Consider Indiana, for example, suffering its fifth twister attack of 2024 after one of the state’s busiest years on record. But, in fact, tornadoes seem to happen in Indiana about as often now as they did in the 1970s.

This might seem counterint­uitive. The supercell thundersto­rms that breed tornadoes thrive on heat, moisture and instabilit­y in the air, something weather nerds call CAPE, or “convective available potential energy.” And climate change is certainly generating plenty of that.

But these storms also need “wind shear,” a change in wind speed and direction at different altitudes. While global warming creates more CAPE, it also creates less wind shear.

In some places and times, warming’s CAPE effect will outweigh its wind-shear effect, producing more tornadoes. In other times and places, the opposite will happen.

Good luck trying to model it. Tornadoes are hyperlocal events that chaoticall­y pop in and out of existence like virtual particles or TikTok dances.

A 2021 study by researcher­s at

Columbia University and Central Michigan University suggested that every one degree Celsius of warming would make tornadofri­endly conditions increase by 5% to 20%, though the actual incidence of severe weather would increase by a little less.

The package of misery

The planet has warmed by about 1.3 degree Celsius above pre-industrial averages so far. Maybe a world of 2.7 degree Celsius warming will have noticeably more supercell storms and other severe weather, including damaging winds and hail.

And a new study from researcher­s at Iowa State University and Lawrence Berkeley National Laboratory suggests that, as the climate warms, tornadoes will increasing­ly be included in the package deal of misery delivered by hurricanes, along with floods, storm surge and high winds.

Again, though, the jury is out. A couple of years back, scientists did notice a trend of fewer days with tornadoes, but many more tornadoes hitting all at once, in clusters, when conditions were right. And they generally expect that the Tornado Alley that cuts through the middle of the U.S. will shift eastward over time and that supercell storms will happen earlier in the year as the planet warms.

That may sound like a wash, but as tornadoes leave the great wide open of the Plains, they will encroach on places where more people live, often in mobile homes and other structures that aren’t prepared for them. The net effect is that the number of severe U.S. storms inflicting at least $1 billion in damage has soared in recent years, setting a record last year, according to the National Oceanic and Atmospheri­c Administra­tion.

Hurricanes are a little easier to predict than tornadoes, and climate models suggest global warming might actually make them happen less often. The same number of hurricanes make landfall in the U.S. today as 125 years ago, according to NASA.

That’s where the good news ends. As Texas A&M University climate scientist Andrew Dessler pointed out in a recent Substack post, hotter air and water — along with the dampening of wind shear — mean the hurricanes that do form will be far more intense and destructiv­e. Rising sea levels will also increase storm surge, and don’t forget about those hurricane-spawned tornadoes (hurrinadoe­s?).

As with tornadoes, the end result could be more deaths and injuries and more monetary damage and losses for insurers, even if hurricanes are fewer in number.

The first lesson here is that we must stop making the climate even more chaotic by burning fossil fuels and pumping greenhouse gases into the atmosphere as quickly as possible. Meanwhile, businesses and homeowners who might think they’re not in harm’s way should consider the possibilit­y that the harm will come to find them.

Policymake­rs need to help vulnerable people prepare for a potentiall­y more dangerous future and ensure that infrastruc­ture and housing can better withstand whatever nature brings. When it comes to disasters, as with car accidents, quantity is far less important than quality.

 ?? Joe Lambert /Camden Courier-Post via AP ?? The aftermath of a tornado in Bensalem, Pa.
Joe Lambert /Camden Courier-Post via AP The aftermath of a tornado in Bensalem, Pa.

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