Unless action is taken to reduce heat-trapping emissions, Lackland Air Force Base could start seeing more than 100 days of extreme heat each year. That’s according to a study released Monday by the Union of Concerned Scientists.
Building on data from UCS’ “Killer Heat” study published in July, the new analysis calculated the increase in dangerously hot days that the 169 major military installations in the continental U.S. would experience by mid-century if no action is taken. An interactive mapping tool shows the results here.
The “no action” scenario is one in which global emissions-cutting efforts continue to be outpaced by increases. The study also includes “slow action” projections — in which emissions rise through mid-century, then decline and stabilize — and “rapid action” projections — wherein humanity takes dramatic steps to reduce emissions.
“We used a set of very high-resolution climate models,” said Kristina Dahl, a senior climate scientist and lead author of the study. “They incorporate a lot of factors like topography, weather patterns, and whether a place tends to be very dry or very humid. They allow us to experiment with different amounts of greenhouse gas emissions in the future.”
The Impact on New Recruits
Statistics for 2018 and 2017 reveal uneven heat injury risks among different military demographics. For instance, the rate of heat-related injury among new recruits is six times higher than the rate for enlisted members. Servicemembers under the age of 20 experience three times as much heat illness as those ages 20-24.
Lackland Air Force is the only base in the country where the Air Force conducts basic training. It’s expected to see 105 days per year with a heat index over 100 degrees Fahrenheit by mid-century, an increase of 69 days.
“That's almost a tripling in a frequency of days that are really dangerously hot. Particularly for new recruits,” said Dahl.
“Of the basic training facilities across all of the branches of the armed services, Lackland is the one that is poised to see the biggest increase in the number of days with a heat index above 100,” she added.
According to Dahl, susceptibility to heat-related illness is very individual, and depends on factors like heat acclimation and underlying health conditions.
“There's really no one temperature or heat index at which we can say everyone would be susceptible,” she said. “That said, we know that, in general, an increasing number of people become susceptible to heat-related illnesses if they're physically exerting themselves outdoors, with a heat index of about 90 degrees.”
Dahl suggested that the military should review its existing heat safety guidelines — and may need to adjust its training schedules to reduce the amount of time recruits spend in the heat.
“There may simply be times of day or times of year — either now or in the near future — where it's simply too hot to be training outside.”
According to the Defense Health Agency, Lackland Air Force Base ranked 14th among military bases for heat injury incidents between 2014 and 2018. 198 incidents occurred in that window.
Joint Base San Antonio-Fort Sam Houston and Randolph were also among the top 15 bases with the largest increases in the frequency of 100-plus degree days, according to the UCS study. It projects that Randolph will see 100 of those extremely hot days each year, while Fort Sam Houston will see 101.
The UCS study projects that every major military installation in Texas will experience more than 100 days per year with temps above 90 degrees by mid-century.
Carson Frame can be reached at Carson@TPR.org and on Twitter at @carson_frame.