USA: Can we survive extreme heat?
Humans have never lived on a planet this hot, and we’re totally unprepared for what’s to come
By Jeff Goodell
Extreme heat is already transforming our world in subtle and not-so-subtle ways. Disney executives recently voiced concern that rising temperatures will significantly reduce the number of visits to their parks. In Germany, officials were forced to put a speed limit on the autobahn because of fears the road would buckle from heat. The U.S. military has already incurred as much as $1 billion in costs during the past decade — from lost work, retraining, and medical care — due to the health impacts of heat. The warming of the planet “will affect the Department of Defense’s ability to defend the nation and poses immediate risks to U.S. national security,” a recent DOD report said. Forests and soils are drying out, contributing to explosive and unprecedented wildfires. Habitation zones for plants and animals are changing, forcing them to adapt to a warmer world or die. A U.N. report found that 1 million species are at risk of extinction in the coming decades. Another study by researchers at MIT suggests that rising temperatures and humidity may make much of South Asia, including parts of India and Pakistan, too hot for human existence by the end of the century. As scientist Peter Gleick, co-founder of the Pacific Institute in California, told me, “There is a shocking, unreported, fundamental change coming to the habitability of many parts of the planet, including the USA.”
How hot will it get? That depends largely on how far and how fast carbon-dioxide levels rise, which depends on how much fossil fuel the world continues to burn. The Paris Climate Agreement (which President Trump pulled the U.S. out of) aims to limit the warming to 3.6°F (2°C). Given the current trajectory of carbon pollution, hitting that target is all but impossible. Unless nations of the world take dramatic action soon, we are headed for a warming of at least 5.4°F (3°C) by the end of the century, making the Earth roughly as warm as it was 3 million years ago during the Pliocene era, long before Homo sapiens came along. “Human beings have literally never lived on a planet as hot as it is today,” says [Michael] Wehner [a scientist at Lawrence Berkeley National Laboratory]. A 5.4°F-warmer world would be radically different from the one we know now, with cities swamped by rising seas and epic droughts turning rainforests into deserts. The increased heat alone would kill significant numbers of people. A recent report from the University of Bristol estimated that with 5.4°F of warming, about 5,800 people could die each year in New York due to the heat, 2,500 could die in Los Angeles, and 2,300 in Miami. “The relationship between heat and mortality is clear,” Eunice Lo, a climate scientist at the University of Bristol and the lead author of the report, tells me. “The warmer the world becomes, the more people die.”
Heat is not an equal-opportunity killer. If you’re poor, sick, old, or homeless, you’re more likely to die during a heat wave. Recent immigrants, both legal and undocumented, are particularly at risk. A 2017 study published in the American Journal of Public Health found that immigrants are three times more likely than citizens to die from heat-related illnesses. More than 85 percent of non-U.S. citizens who died from heat-related causes were Hispanic. Researchers hypothesized that working outdoors and in agriculture increased vulnerability.