The Heat Will Kill You First: Life and Death on a Scorched Planet

by Jeff Goodell

And the notion that eight billion people are going to thrive on a hotter planet by simply cranking up the air-conditioning or seeking refuge under a pine tree is a profound misunderstanding of the future we are creating for ourselves.

In a world of heat-driven chaos, heat exposes deep fissures of inequity and injustice. Poverty equals vulnerability. If you have money, you can turn up the air-conditioning, stock up on food and bottled water, and install a backup generator in case there’s a blackout. If things get bad enough, you can sell your house and move to a cooler place. If you’re poor, on the other hand, you swelter in an uninsulated apartment or trailer with no air-conditioning or an old, inefficient machine that you can’t afford to run. You can’t move somewhere cooler because you’re afraid of losing your job and you don’t have the savings to start over. “We’re all in the storm, but we’re not in the same boat,” Heather McTeer Toney, the former mayor of Greenville, Mississippi, said during testimony before the US Congress. “Some of us are sitting on aircraft carriers while others are just bobbing along on a floatie.”

Heat lowers children’s test scores and raises the risk of miscarriage in pregnant women. Prolonged exposure increases death rates from heart and kidney disease. When people are stressed by heat, they are more impulsive and prone to conflict. Racial slurs and hate speech in social media spike. Suicides rise. Gun violence increases. There are more rapes and more violent crime. In Africa and the Middle East, studies have found a link between higher temperatures and the outbreak of civil war.

There is a lot of confusion about the relationship between water and heat exhaustion and heatstroke. Water is necessary to keep sweat flowing. If you get dehydrated, you can’t sweat. And if you can’t sweat, you can’t cool off. But drinking water does not in itself cool off inner-core body temperatures. Put another way, dehydration can exacerbate heat exhaustion and heatstroke, but you can still die of heatstroke and be well hydrated.

The only effective treatment for heatstroke is to get a person’s core body temperature down, fast. A cold shower or bath, or tubs (or, as I mentioned in the prologue, body bags) of ice, is one way to do this. Another is to quickly cool places on the body where, because of the structure of our veins, a lot of blood circulates close to the surface: the bottoms of the feet, the palms of the hands, the upper part of the face.

after you spend a few weeks in a hot climate, your body makes subtle adjustments that help you better tolerate heat stress.2 Your normal deep body temperature drops. Your body sweats at a lower temperature, and so there is less strain on your heart, which keeps your heart rate from rising fast. At the same time, your heart pumps more blood per stroke. Your body retains more fluids and blood volume rises, increasing water reserves for sweating and cooling. But these changes are not permanent. “If you go out of the heat, within a few weeks all the adaptations go back to zero,” says Sam Cheuvront.

Interestingly, exposure to air-conditioning even for brief periods slows or even stops acclimatization.

“Heat moves less like a river through a canyon and more like laughter through a crowd,” writes physicist Brian Greene.

For every degree Celsius of increase in global mean temperature, yields are expected to decrease by 7 percent for corn, 6 percent for wheat, and 3 percent for rice.

“The largest single global change that threatens food security is high temperature.”

“There are so many other potential new crop species out there that could be far more drought-intensive or heat-tolerant than even any of the ones we’re working on right now,” says Tim Crews, chief scientist at the Land Institute, a nonprofit agricultural research group in Salina, Kansas, where Kernza was bred (and trademarked) from wild wheatgrass.

Promising as all this may be, you have to be a pretty hard-core technofuturist to imagine growing enough corn and wheat under glass to feed millions of hungry people.

As a result of the Blob, many of the kelp forests along the coast from California to Oregon have vanished, done in by warming and the army of purple sea urchins, which thrive in a hotter world. “If a two-hundred-mile-long stretch of forest in the California mountains suddenly died, people would be shocked and outraged,” Laura Rogers-Bennett, a marine scientist with the California Department of Fish and Wildlife, told me when I visited her at the Bodega Marine Lab a few days after our dive. “We’re talking about the collapse of an entire ecosystem. But because it happened in the ocean, nobody notices.”

heat waves in the Mediterranean, where water temperatures spiked as much as eleven degrees above normal, “the equivalent of underwater wildfires, with fauna and flora dying just as if they had been burned.”

Indeed, on my visits to the Great Barrier Reef, I’ve disembarked from the mainland at a dock only a stone’s throw from a massive coal transport terminal, where coal-filled barges carry Australian coal to Indonesia and China. Watching a coal barge float over the Great Barrier Reef is a surreal sight for anyone who cares about the future of the reef—or life on our planet.

“By midcentury, pretty much every reef in the world will be eroding away,” Ken Caldeira told me. That’s astonishing. Coral reefs have been around for about 250 million years, evolving into some of the most complex, diverse, and beautiful living structures on Earth. And yet, if nothing changes, within forty or fifty years they will be crumbling ruins. “I think if we stopped emitting CO2 tomorrow, some reefs would probably survive,” Caldeira said. “But if we go on a few more decades, I think the reefs are gone. Over geological time scales, they will come back, depending how long it takes the ocean chemistry to recover. But it’s likely to be at least ten thousand years before anyone sees a reef again.”

“Rich countries have brought much of their economy indoors where air-conditioning is a possibility, but many developing economies rely on labor-intensive outdoor work,” says climate scientist Ken Caldeira. “The combination of poverty and extreme temperatures can be lethal.”

In the US, there are no federal rules related to heat exposure for workers—indoors or out. Farmworkers, who are excluded from national laws requiring overtime pay, as well as the right to collective bargaining, are particularly vulnerable. For decades, farmworker groups and labor activists have been lobbying the Department of Labor’s Occupational Health and Safety Administration (OSHA), which is responsible for workplace safety and worker rights, to develop rules for heat exposure. In 2021, the Asunción Valdivia Heat Illness and Fatality Prevention Act was introduced in the US House of Representatives. The main purpose of the legislation, named after a California farmworker who died of heatstroke in 2004 after picking grapes for ten straight hours on a 105-degree day, is to finally require OSHA to develop heat rules. As I write this in early 2023, the chances that the legislation will make it to the House floor for a vote anytime soon are virtually zero.

“It’s enraging, in a slow and violent way, to think about how heat death is entirely preventable,” said Elizabeth Strater, director of strategic campaigns for United Farm Workers. “It doesn’t take cutting-edge technologies, or expensive machinery. It takes shade and cool water and rest. That is all. The way that this industry has disrespected and refused to provide this to workers is just criminal.”

How close West Antarctica is to collapse is one of the most urgent and consequential questions of our time. A stable West Antarctic ice sheet means coastal cities around the world will likely have time to adapt to rising seas. An unstable West Antarctic ice sheet means goodbye Miami—and virtually every other low-lying coastal city in the world.

Mercer argued that this whole system was much more unstable than anyone had yet realized. “I contend that a major disaster—a rapid five meter [16 foot] rise in sea level, caused by the deglaciation of West Antarctica—may be imminent,” he wrote, predicting it would lead to the “submergence of low-lying areas like Florida and the Netherlands.” Mercer didn’t know how soon this might happen, but when he made his calculations in the mid-1970s, he predicted that if fossil fuel consumption continued to accelerate, it could begin in fifty years. That is, right about now.

I find myself thinking about life in Austin. The music and the bars, the highways and the traffic, the new buildings downtown and the boats on the lake—all the buzz of civilization, all the life, all the heat. I imagine the molecules in the city all vibrating faster, and those molecules bumping into other molecules, until finally the dancing molecules vibrate all the way down to Antarctica, a place so remote that I am one of the first humans ever to sail these waters. I know that isn’t how it works, but I also know it sorta is. The heat we generate in modern life cannot be contained. It is not localized, like the soot that spews out of the 4x4s blasting through the city. The heat of life in Austin—or Bangkok or Rio de Janeiro or Sydney—is the heat of the world. And it touches everything.

“Seeing this glacier makes you realize that things you think will always be there might not be. That’s quite a thing to get your head around.”

They found that in all but three of the homes, the preferred temperature was 72 degrees, with low humidity, a combination that most closely resembled the temperature and humidity in East Africa—the same region of the continent where the first humans lived hundreds of thousands of years ago. As Mark Maslin, a paleoclimatologist at University College London, observed, the findings suggest that even when people can set the temperature and humidity at whatever they want, “they then choose something that harks back a hundred thousand years to Africa.”

Kalkstein had developed a system called spatial synoptic classification, which identifies eight different types of air masses: dry tropical, moist tropical, etc. He looks at cities and sees how these different air masses correlate with data from all causes of mortality for the region. He can see that in, say, Albuquerque, when a dry tropical air mass moves in, the mortality rate spikes by 15 percent. If he does this correlation enough times with air masses in any given city, he can get a pretty good estimate for how many people that air mass will kill whenever it arrives.