There were two poets among the crew, Aka Niviana, who is Greenlandic, and Kathy Jetnil-Kijiner, from the low-lying Marshall Islands, in the Pacific, where “king tides” recently washed through living rooms and unearthed graveyards. A small lens of fresh water has supported life on the Marshall Islands’ atolls for millennia, but, as salt water intrudes, breadfruit trees and banana palms wilt and die. As the Greenlandic ice we were gazing at continues to melt, the water will drown Jetnil-Kijiner’s homeland. About a third of the carbon responsible for these changes has come from the United States.
A few days after the boat trip, the two poets and I accompanied the scientists to another fjord, where they needed to change the memory card on a camera that tracks the retreat of the ice sheet. As we took off for the flight home over the snout of a giant glacier, an eight-story chunk calved off the face and crashed into the ocean. I’d never seen anything quite like it for sheer power—the waves rose twenty feet as it plunged into the dark water. You could imagine the same waves washing through the Marshalls. You could almost sense the ice elevating the ocean by a sliver—along the seafront in Mumbai, which already floods on a stormy day, and at the Battery in Manhattan, where the seawall rises just a few feet above the water.
When I say the world has begun to shrink, this is what I mean. Until now, human beings have been spreading, from our beginnings in Africa, out across the globe—slowly at first, and then much faster. But a period of contraction is setting in as we lose parts of the habitable earth. Sometimes our retreat will be hasty and violent; the effort to evacuate the blazing California towns along narrow roads was so chaotic that many people died in their cars. But most of the pullback will be slower, starting along the world’s coastlines. Each year, another twenty-four thousand people abandon Vietnam’s sublimely fertile Mekong Delta as crop fields are polluted with salt. As sea ice melts along the Alaskan coast, there is nothing to protect towns, cities, and native villages from the waves. In Mexico Beach, Florida, which was all but eradicated by Hurricane Michael, a resident told the Washington Post, “The older people can’t rebuild; it’s too late in their lives. Who is going to be left? Who is going to care?”
In one week at the end of last year, I read accounts from Louisiana, where government officials were finalizing a plan to relocate thousands of people threatened by the rising Gulf (“Not everybody is going to live where they are now and continue their way of life, and that is a terrible, and emotional, reality to face,” one state official said); from Hawaii, where, according to a new study, thirty-eight miles of coastal roads will become impassable in the next few decades; and from Jakarta, a city with a population of ten million, where a rising Java Sea had flooded the streets. In the first days of 2018, a nor’easter flooded downtown Boston; dumpsters and cars floated through the financial district. “If anyone wants to question global warming, just see where the flood zones are,” Marty Walsh, the mayor of Boston, told reporters. “Some of those zones did not flood thirty years ago.”
According to a study from the United Kingdom’s National Oceanography Centre last summer, the damage caused by rising sea levels will cost the world as much as fourteen trillion dollars a year by 2100, if the U.N. targets aren’t met. “Like it or not, we will retreat from most of the world’s non-urban shorelines in the not very distant future,” Orrin Pilkey, an expert on sea levels at Duke University, wrote in his book “Retreat from a Rising Sea.” “We can plan now and retreat in a strategic and calculated fashion, or we can worry about it later and retreat in tactical disarray in response to devastating storms. In other words, we can walk away methodically, or we can flee in panic.”
But it’s not clear where to go. As with the rising seas, rising temperatures have begun to narrow the margins of our inhabitation, this time in the hot continental interiors. Nine of the ten deadliest heat waves in human history have occurred since 2000. In India, the rise in temperature since 1960 (about one degree Fahrenheit) has increased the chance of mass heat-related deaths by a hundred and fifty per cent. The summer of 2018 was the hottest ever measured in certain areas. For a couple of days in June, temperatures in cities in Pakistan and Iran peaked at slightly above a hundred and twenty-nine degrees Fahrenheit, the highest reliably recorded temperatures ever measured. The same heat wave, nearer the shore of the Persian Gulf and the Gulf of Oman, combined triple-digit temperatures with soaring humidity levels to produce a heat index of more than a hundred and forty degrees Fahrenheit. June 26th was the warmest night in history, with the mercury in one Omani city remaining above a hundred and nine degrees Fahrenheit until morning. In July, a heat wave in Montreal killed more than seventy people, and Death Valley, which often sets American records, registered the hottest month ever seen on our planet. Africa recorded its highest temperature in June, the Korean Peninsula in July, and Europe in August. The Times reported that, in Algeria, employees at a petroleum plant walked off the job as the temperature neared a hundred and twenty-four degrees. “We couldn’t keep up,” one worker told the reporter. “It was impossible to do the work.”
This was no illusion; some of the world is becoming too hot for humans. According to the National Oceanic and Atmospheric Administration, increased heat and humidity have reduced the amount of work people can do outdoors by ten per cent, a figure that is predicted to double by 2050. About a decade ago, Australian and American researchers, setting out to determine the highest survivable so-called “wet-bulb” temperature, concluded that when temperatures passed thirty-five degrees Celsius (ninety-five degrees Fahrenheit) and the humidity was higher than ninety per cent, even in “well-ventilated shaded conditions,” sweating slows down, and humans can survive only “for a few hours, the exact length of time being determined by individual physiology.”
As the planet warms, a crescent-shaped area encompassing parts of India, Pakistan, Bangladesh, and the North China Plain, where about 1.5 billion people (a fifth of humanity) live, is at high risk of such temperatures in the next half century. Across this belt, extreme heat waves that currently happen once every generation could, by the end of the century, become “annual events with temperatures close to the threshold for several weeks each year, which could lead to famine and mass migration.” By 2070, tropical regions that now get one day of truly oppressive humid heat a year can expect between a hundred and two hundred and fifty days, if the current levels of greenhouse-gas emissions continue. According to Radley Horton, a climate scientist at the Lamont-Doherty Earth Observatory, most people would “run into terrible problems” before then. The effects, he added, will be “transformative for all areas of human endeavor—economy, agriculture, military, recreation.”
Humans share the planet with many other creatures, of course. We have already managed to kill off sixty per cent of the world’s wildlife since 1970 by destroying their habitats, and now higher temperatures are starting to take their toll. A new study found that peak-dwelling birds were going extinct; as temperatures climb, the birds can no longer find relief on higher terrain. Coral reefs, rich in biodiversity, may soon be a tenth of their current size.
As some people flee humidity and rising sea levels, others will be forced to relocate in order to find enough water to survive. In late 2017, a study led by Manoj Joshi, of the University of East Anglia, found that, by 2050, if temperatures rise by two degrees a quarter of the earth will experience serious drought and desertification. The early signs are clear: São Paulo came within days of running out of water last year, as did Cape Town this spring. In the fall, a record drought in Germany lowered the level of the Elbe to below twenty inches and reduced the corn harvest by forty per cent. The Potsdam Institute for Climate Impact Research concluded in a recent study that, as the number of days that reach eighty-six degrees Fahrenheit or higher increases, corn and soybean yields across the U.S. grain belt could fall by between twenty-two and forty-nine per cent. We’ve already overpumped the aquifers that lie beneath most of the world’s breadbaskets; without the means to irrigate, we may encounter a repeat of the nineteen-thirties, when droughts and deep plowing led to the Dust Bowl—this time with no way of fixing the problem. Back then, the Okies fled to California, but California is no longer a green oasis. A hundred million trees died in the record drought that gripped the Golden State for much of this decade. The dead limbs helped spread the waves of fire, as scientists earlier this year warned that they could.
Thirty years ago, some believed that warmer temperatures would expand the field of play, turning the Arctic into the new Midwest. As Rex Tillerson, then the C.E.O. of Exxon, cheerfully put it in 2012, “Changes to weather patterns that move crop production areas around—we’ll adapt to that.” But there is no rich topsoil in the far North; instead, the ground is underlaid with permafrost, which can be found beneath a fifth of the Northern Hemisphere. As the permafrost melts, it releases more carbon into the atmosphere. The thawing layer cracks roads, tilts houses, and uproots trees to create what scientists call “drunken forests.” Ninety scientists who released a joint report in 2017 concluded that economic losses from a warming Arctic could approach ninety trillion dollars in the course of the century, considerably outweighing whatever savings may have resulted from shorter shipping routes as the Northwest Passage unfreezes.
Churchill, Manitoba, on the edge of the Hudson Bay, in Canada, is connected to the rest of the country by a single rail line. In the spring of 2017, record floods washed away much of the track. OmniTrax, which owns the line, tried to cancel its contract with the government, declaring what lawyers call a “force majeure,” an unforeseen event beyond its responsibility. “To fix things in this era of climate change—well, it’s fixed, but you don’t count on it being the fix forever,” an engineer for the company explained at a media briefing in July. This summer, the Canadian government reopened the rail at a cost of a hundred and seventeen million dollars—about a hundred and ninety thousand dollars per Churchill resident. There is no reason to think the fix will last, and every reason to believe that our world will keep contracting.
All this has played out more or less as scientists warned, albeit faster. What has defied expectations is the slowness of the response. The climatologist James Hansen testified before Congress about the dangers of human-caused climate change thirty years ago. Since then, carbon emissions have increased with each year except 2009 (the height of the global recession) and the newest data show that 2018 will set another record. Simple inertia and the human tendency to prioritize short-term gains have played a role, but the fossil-fuel industry’s contribution has been by far the most damaging. Alex Steffen, an environmental writer, coined the term “predatory delay” to describe “the blocking or slowing of needed change, in order to make money off unsustainable, unjust systems in the meantime.” The behavior of the oil companies, which have pulled off perhaps the most consequential deception in mankind’s history, is a prime example.
As journalists at InsideClimate News and the Los Angeles Times have revealed since 2015, Exxon, the world’s largest oil company, understood that its product was contributing to climate change a decade before Hansen testified. In July, 1977, James F. Black, one of Exxon’s senior scientists, addressed many of the company’s top leaders in New York, explaining the earliest research on the greenhouse effect. “There is general scientific agreement that the most likely manner in which mankind is influencing the global climate is through carbon-dioxide release from the burning of fossil fuels,” he said, according to a written version of the speech which was later recorded, and which was obtained by InsideClimate News. In 1978, speaking to the company’s executives, Black estimated that a doubling of the carbon-dioxide concentration in the atmosphere would increase average global temperatures by between two and three degrees Celsius (5.4 degrees Fahrenheit), and as much as ten degrees Celsius (eighteen degrees Fahrenheit) at the poles.
Exxon spent millions of dollars researching the problem. It outfitted an oil tanker, the Esso Atlantic, with CO2 detectors to measure how fast the oceans could absorb excess carbon, and hired mathematicians to build sophisticated climate models. By 1982, they had concluded that even the company’s earlier estimates were probably too low. In a private corporate primer, they wrote that heading off global warming and “potentially catastrophic events” would “require major reductions in fossil fuel combustion.”
An investigation by the L.A. Times revealed that Exxon executives took these warnings seriously. Ken Croasdale, a senior researcher for the company’s Canadian subsidiary, led a team that investigated the positive and negative effects of warming on Exxon’s Arctic operations. In 1991, he found that greenhouse gases were rising due to the burning of fossil fuels. “Nobody disputes this fact,” he said. The following year, he wrote that “global warming can only help lower exploration and development costs” in the Beaufort Sea. Drilling season in the Arctic, he correctly predicted, would increase from two months to as many as five months. At the same time, he said, the rise in the sea level could threaten onshore infrastructure and create bigger waves that would damage offshore drilling structures. Thawing permafrost could make the earth buckle and slide under buildings and pipelines. As a result of these findings, Exxon and other major oil companies began laying plans to move into the Arctic, and started to build their new drilling platforms with higher decks, to compensate for the anticipated rises in sea level.
The implications of the exposés were startling. Not only did Exxon and other companies know that scientists like Hansen were right; they used his NASA climate models to figure out how low their drilling costs in the Arctic would eventually fall. Had Exxon and its peers passed on what they knew to the public, geological history would look very different today. The problem of climate change would not be solved, but the crisis would, most likely, now be receding. In 1989, an international ban on chlorine-containing man-made chemicals that had been eroding the earth’s ozone layer went into effect. Last month, researchers reported that the ozone layer was on track to fully heal by 2060. But that was a relatively easy fight, because the chemicals in question were not central to the world’s economy, and the manufacturers had readily available substitutes to sell. In the case of global warming, the culprit is fossil fuel, the most lucrative commodity on earth, and so the companies responsible took a different tack.
A document uncovered by the L.A. Times showed that, a month after Hansen’s testimony, in 1988, an unnamed Exxon “public affairs manager” issued an internal memo recommending that the company “emphasize the uncertainty” in the scientific data about climate change. Within a few years, Exxon, Chevron, Shell, Amoco, and others had joined the Global Climate Coalition, “to coordinate business participation in the international policy debate” on global warming. The G.C.C. coördinated with the National Coal Association and the American Petroleum Institute on a campaign, via letters and telephone calls, to prevent a tax on fossil fuels, and produced a video in which the agency insisted that more carbon dioxide would “end world hunger” by promoting plant growth. With such efforts, it ginned up opposition to the Kyoto Protocol, the first global initiative to address climate change.