Stephen Strader is a professor in Villanova University’s Department of Geography and the Environment. He studies disasters, which he says requires him to be half-geographer, half-meteorologist.
Tornado Alley may be shifting — that’s the meteorology part. But communities are changing too, which affects a tornado’s impact.
“When we think about disasters, we don't care about the tornado that's in the middle of a field,” Strader said. “Maybe two farmers care about it because it hurts their crops. But if it doesn't hit anything, it doesn't become a disaster.”
If the same tornado plowed through a subdivision or a mobile home park, it would create death, destruction and huge monetary losses.
A few years ago, a research study showed that people in the Mid-South — places like Tennessee, Mississippi and Arkansas — see a few more days every decade when all the ingredients are there to produce tornadoes than they were in the 1980s. And the Southern Plains — mostly Oklahoma and Texas — see a couple fewer tornado days every decade.
“So the big topic became, oh, no, climate change is shifting severe weather towards the east. And that might be true, but it's really not a shift,” Strader said. “The Central Plains is still going to get tornadoes. The Southern Plains is still going to get tornadoes.”
But Strader’s research shows those tornadoes are likely to do more damage than they would have in the 1980s. To explain why, he often asks people to close their eyes and picture the place they grew up.
“If you grew up in the suburbs, think what it looked like when you were a child, and now what it looks like today,” Strader said. “Sprawl is just continuing to go and go and go. You see that southern Oklahoma City, you see that around Tulsa, you see all these areas where the urban sprawl is playing a role, we're essentially creating more targets for these tornadoes to hit.”
Strader took data about population growth and density change over time for his new study.
“What I did was let's take those areas where we've seen an increase in a decrease, and let's look at what's happened in that same time period to society,” he said.
Some parts of the Mid-South are seeing more tornado days, and their populations are growing. Those ingredients combine to make tornadoes three times as impactful as they were in the 1980s. And even with fewer tornado days in the Southern Plains, tornado impacts are up 50%.
In addition to sprawl, Strader said societal factors like poverty and inequity are making people more vulnerable to tornadoes. And more people live in manufactured homes compared to 40 years ago.
“Manufactured housing makes up 7% of the US housing stock, but they're a factor in over 50%, of tornado deaths,” Strader said.
Because there are so many different components to tornado vulnerability, there are a lot of different ways to make things just a little better.
“A lot of people say, ‘What can I do?’” Strader said. “‘What is something that I can do to stop climate change?’ Well, we're not going to stop the tornado, but we certainly can decide to build homes stronger and come up with new ways to make them more resilient to wind and damage.”
Strader says it will take meteorologists, engineers and social scientists working together to keep us safe. Anyone can decrease their disaster risk by making sure they have access to early weather warnings and creating a solid tornado plan.
