A pedestrian uses an umbrella to get some relief from the sun as she walks past a temperature sign on June 20, 2017 in Phoenix, Arizona.
Ralph Freso | Getty Images
Heat records are falling across the world this summer, and scientists expect climate change to exacerbate the problem in the coming years.
Next year, about 50 U.S. counties, home to more than 8 million residents, are expected to experience heat index temperatures of more than 125 degrees Fahrenheit, according to a new model released Monday by the First Street Foundation, a nonprofit research and technology group that is working on climate risk assessment.
That puts those counties at the highest level on the National Weather Service’s heat index, which combines temperatures with humidity readings to estimate how hot it really feels outside.
Thirty years later, those extreme temperatures will be experienced in more than a thousand counties, home to about 108 million Americans. First Street uses the 30-year model because that is the length of the most popular mortgage product in the US. Heat, flood and fire risks increasingly play a role in home values as climate change begins to play a role in home buying decisions.
The area with the greatest increase in heat is the south. Texas and Florida will bear the brunt of climate change, with the number of days of extreme heat nearly doubling over the next 30 years. This is where much of the country has migrated in recent years, as the culture of work everywhere emerged and people fled to sunnier climates.
The Midwest will also see big changes. First Street outlined an “Extreme Heat Belt” going from North Texas and Louisiana to Illinois, Indiana, and up to Wisconsin. Unlike Florida, which will see the most extreme heat days, the Midwest has far less available water to mitigate the heat. Higher humidity also makes the heat less tolerable there than in drier areas like Phoenix.
“We have to be prepared for the inevitable, that a quarter of the country will soon fall into the Extreme Heat Belt with temperatures over 125°F and the results will be dire,” said Matthew Eby, CEO of First Street Foundation.
First Street uses high-resolution measurements of land surface temperatures, canopy cover, impervious surfaces (such as streets and parking lots), land cover, and proximity to water to calculate current heat exposure, then adjusts for future predicted United States emissions scenarios. Intergovernmental Panel of the Nations on Climate Change. This makes it possible to determine the number of days that a home is expected to experience dangerous levels of heat.
The group already has flood and fire forecasts for every home in America, which can be accessed both on its website and on Realtor.com. The heat factor so far is only on the First Street website.
Eby says the heat increase will inevitably lead to more climate migration, which is already underway in some increasingly flood- and fire-prone areas.
“When people move, you have an impact on the tax base and the demand for properties and values in general changes,” he said.
Since the models are based on the current targets of the Paris Climate Agreement, they may change depending on the outcome of emissions commitments. First Street’s scenario uses a moderate model, with global emissions peaking by 2040.
“We’re actually low on our forecast because everyone else should be cutting like us, which they aren’t,” Eby said. “If anything, we’ll be low. The emissions scenarios will be worse.”