For now, it isn’t budging. But eventually, the “heat dome” that has parked itself over Texas and is sending temperatures soaring to triple digits will expand to other parts of the nation, putting millions more people at risk and further straining an already-overwhelmed power grid.
As sobering as that news may be, it pales in comparison to what’s to come: “heat domes”—high-pressure systems high in the atmosphere that trap heat over an area, much like a lid on a pot holds in steam—will only become more frequent and intense as the climate crisis worsens, according to a leading University of Miami atmospheric scientist.
“We talk a lot about how the average global temperature is 1.1 degrees Celsius higher than it was at the start of the industrial age. But what does that tell us about how climate change will impact humans? The way we’re really going to experience it is we’re going to see these prolonged periods of intense heat more frequently,” said Ben Kirtman, professor of atmospheric sciences at the Rosenstiel School of Marine, Atmospheric, and Earth Science and the William R. Middelthon III Endowed Chair in Earth Sciences.
Already, heat domes can have deadly consequences, especially when they persist for weeks and stretch over several states. The 1980 U.S. heat wave, which began in June and lasted until mid-September, overwhelmed much of the Midwestern United States and Southern Plains with triple-digit temperatures, causing an estimated 10,000 direct and indirect heat-related deaths and about $20 billion in agricultural damage.
A ramping up in the frequency and intensity of heat domes only will worsen their impacts on people, with children, the elderly, and those with chronic diseases most at risk, said health geographer Imelda Moise, an associate professor and director of Global Health Studies in the College of Arts and Sciences.
“In Miami, we also need to consider the impact [heat waves] have on our homeless population and on families living below the poverty line who most likely live in poorly ventilated homes or mobile homes without air-conditioning and who can’t afford the costs of cooling,” Moise explained. “We need to be proactive and invest in the cocreation of community solutions such as tree planning to increase canopy cover. And most importantly, we need to have the capacity to identify vulnerable populations and reach them in a timely manner.”
Extreme heat, Kirtman pointed out, is the No. 1 weather-related cause of death in the U.S., killing more people most years than floods, tornadoes, and tropical cyclones combined. A record-breaking heat wave in Europe in 2003 left more than 20,000 people dead.
The brutal heat dome now camped over Texas—which Kirtman’s multi-model Subseasonal Experiment, or SubX, forecasting accurately predicted two weeks before it occurred—is a bit of an anomaly, he pointed out.
“It’s been unusually persistent,” he said. “Descending air tends to be associated with heat domes. But with this one, there’s not only that descending air. It’s also sucking in moisture from the Gulf of Mexico, so it’s been extremely humid. And what that means is it doesn’t cool off at night. There’s no respite from the heat. And that’s creating a dangerous situation.”
Eventually, the dome will dislodge, but that likely will not happen until next week, Kirtman said.
He recommended that people heed advice from the Centers for Disease Control and Prevention for keeping cool in hot weather. Among its tips, the CDC advises everyone to stay in an air-conditioned indoor location as much as possible and to drink plenty of fluids.