David Wallace-Wells: The Uninhabitable Earth

It is worse, much worse, than you think. The slowness of climate change is a fairy tale, perhaps as pernicious as the one that says it isn’t happening at all, and comes to us bundled with several others in an anthology of comforting delusions: that global warming is an Arctic saga, unfolding remotely; that it is strictly a matter of sea level and coastlines, not an enveloping crisis sparing no place and leaving no life undeformed; that it is a crisis of the “natural” world, not the human one; that those two are distinct, and that we live today somehow outside or beyond or at the very least defended against nature, not inescapably within and literally overwhelmed by it; that wealth can be a shield against the ravages of warming; that the burning of fossil fuels is the price of continued economic growth; that growth, and the technology it produces, will allow us to engineer our way out of environmental disaster; that there is any analogue to the scale or scope of this threat, in the long span of human history, that might give us confidence in staring it down. None of this is true. But let’s begin with the speed of change. The earth has experienced five mass extinctions before the one we are living through now, each so complete a wiping of the fossil record that it functioned as an evolutionary reset, the planet’s phylogenetic tree first expanding, then collapsing, at intervals, like a lung: 86 percent of all species dead, 450 million years ago; 70 million years later, 75 percent; 125 million years later, 96 percent; 50 million years later, 80 percent; 135 million years after that, 75 percent again. Unless you are a teenager, you probably read in your high school textbooks that these extinctions were the result of asteroids. In fact, all but the one that killed the dinosaurs involved climate change produced by greenhouse gas. The most notorious was 250 million years ago; it began when carbon dioxide warmed the planet by five degrees Celsius, accelerated when that warming triggered the release of methane, another greenhouse gas, and ended with all but a sliver of life on Earth dead. We are currently adding carbon to the atmosphere at a considerably faster rate; by most estimates, at least ten times faster. The rate is one hundred times faster than at any point in human history before the beginning of industrialization. And there is already, right now, fully a third more carbon in the atmosphere than at any point in the last 800,000 years—perhaps in as long as 15 million years. There were no humans then. The oceans were more than a hundred feet higher.


In fact, the belief that climate could be plausibly governed, or managed, by any institution or human instrument presently at hand is another wide-eyed climate delusion. The planet survived many millennia without anything approaching a world government, in fact endured nearly the entire span of human civilization that way, organized into competitive tribes and fiefdoms and kingdoms and nation-states, and only began to build something resembling a cooperative blueprint, very piecemeal, after brutal world wars—in the form of the League of Nations and United Nations and European Union and even the market fabric of globalization, whatever its flaws still a vision of cross-national participation, imbued with the neoliberal ethos that life on Earth was a positive-sum game. If you had to invent a threat grand enough, and global enough, to plausibly conjure into being a system of true international cooperation, climate change would be it—the threat everywhere, and overwhelming, and total. And yet now, just as the need for that kind of cooperation is paramount, indeed necessary for anything like the world we know to survive, we are only unbuilding those alliances—recoiling into nationalistic corners and retreating from collective responsibility and from each other. That collapse of trust is a cascade, too.


Humans, like all mammals, are heat engines; surviving means having to continually cool off, as panting dogs do. For that, the temperature needs to be low enough for the air to act as a kind of refrigerant, drawing heat off the skin so the engine can keep pumping. At seven degrees of warming, that would become impossible for portions of the planet’s equatorial band, and especially the tropics, where humidity adds to the problem. And the effect would be fast: after a few hours, a human body would be cooked to death from both inside and out. At eleven or twelve degrees Celsius of warming, more than half the world’s population, as distributed today, would die of direct heat. Things almost certainly won’t get that hot anytime soon, though some models of unabated emissions do bring us that far eventually, over centuries. But at just five degrees, according to some calculations, whole parts of the globe would be literally unsurvivable for humans. At six, summer labor of any kind would become impossible in the lower Mississippi Valley, and everybody in the United States east of the Rockies would suffer more from heat than anyone, anywhere, in the world today. New York City would be hotter than present-day Bahrain, one of the planet’s hottest spots, and the temperature in Bahrain “would induce hyperthermia in even sleeping humans.


We think of climate change as slow, but it is unnervingly fast. We think of the technological change necessary to avert it as fast-arriving, but unfortunately it is deceptively slow—especially judged by just how soon we need it. This is what Bill McKibben means when he says that winning slowly is the same as losing: “If we don’t act quickly, and on a global scale, then the problem will literally become insoluble,” he writes. “The decisions we make in 2075 won’t matter.” Innovation, in many cases, is the easy part. This is what the novelist William Gibson meant when he said, “The future is already here, it just isn’t evenly distributed.” Gadgets like the iPhone, talismanic for technologists, give a false picture of the pace of adaptation. To a wealthy American or Swede or Japanese, the market penetration may seem total, but more than a decade after its introduction, the device is used by less than 10 percent of the world; for all smartphones, even the “cheap” ones, the number is somewhere between a quarter and a third. Define the technology in even more basic terms, as “cell phones” or “the internet,” and you get a timeline to global saturation of at least decades—of which we have two or three, in which to completely eliminate carbon emissions, planetwide. According to the IPCC, we have just twelve years to cut them in half. The longer we wait, the harder it will be. If we had started global decarbonization in 2000, when Al Gore narrowly lost election to the American presidency, we would have had to cut emissions by only about 3 percent per year to stay safely under two degrees of warming. If we start today, when global emissions are still growing, the necessary rate is 10 percent. If we delay another decade, it will require us to cut emissions by 30 percent each year. This is why U.N. Secretary-General António Guterres believes we have only one year to change course and get started. The scale of the technological transformation required dwarfs any achievement that has emerged from Silicon Valley—in fact dwarfs every technological revolution ever engineered in human history, including electricity and telecommunications and even the invention of agriculture ten thousand years ago. It dwarfs them by definition, because it contains all of them—every single one needs to be replaced at the root, since every single one breathes on carbon, like a ventilator.


Over the past fifteen years, the iconoclastic mathematician Irakli Loladze has isolated a dramatic effect of carbon dioxide on human nutrition unanticipated by plant physiologists: it can make plants bigger, but those bigger plants are less nutritious. “Every leaf and every grass blade on earth makes more and more sugars as CO2 levels keep rising,” Loladze told Politico, in a story about his work headlined “The Great Nutrient Collapse.” “We are witnessing the greatest injection of carbohydrates into the biosphere in human history—[an] injection that dilutes other nutrients in our food supply.” Since 1950, much of the good stuff in the plants we grow—protein, calcium, iron, vitamin C, to name just four—has declined by as much as one-third, a landmark 2004 study showed. Everything is becoming more like junk food. Even the protein content of bee pollen has dropped by a third. The problem has gotten worse as carbon concentrations have gotten worse. Recently, researchers estimated that by 2050 as many as 150 million people in the developing world will be at risk of protein deficiency as the result of nutrient collapse, since so many of the world’s poor depend on crops, rather than animal meat, for protein; 138 million could suffer from a deficiency of zinc, essential to healthy pregnancies; and 1.4 billion could face a dramatic decline in dietary iron—pointing to a possible epidemic of anemia. In 2018, a team led by Chunwu Zhu looked at the protein content of eighteen different strains of rice, the staple crop for more than 2 billion people, and found that more carbon dioxide in the air produced nutritional declines across the board—drops in protein content, as well as in iron, zinc, and vitamins B1, B2, B5, and B9. Really everything but vitamin E. Overall, the researchers found that, acting just through that single crop, rice, carbon emissions could imperil the health of 600 million people. In previous centuries, empires were built on that crop. Climate change promises another, an empire of hunger, erected among the world’s poor.


Early naturalists talked often about “deep time”—the perception they had, contemplating the grandeur of this valley or that rock basin, of the profound slowness of nature. But the perspective changes when history accelerates. What lies in store for us is more like what aboriginal Australians, talking with Victorian anthropologists, called “dreamtime,” or “everywhen”: the semi-mythical experience of encountering, in the present moment, an out-of-time past, when ancestors, heroes, and demigods crowded an epic stage. You can find it already by watching footage of an iceberg collapsing into the sea—a feeling of history happening all at once. It is. The summer of 2017, in the Northern Hemisphere, brought unprecedented extreme weather: three major hurricanes arising in quick succession in the Atlantic; the epic “500,000-year” rainfall of Hurricane Harvey, dropping on Houston a million gallons of water for nearly every single person in the entire state of Texas; the wildfires of California, nine thousand of them burning through more than a million acres, and those in icy Greenland, ten times bigger than those in 2014; the floods of South Asia, clearing 45 million from their homes. Then the record-breaking summer of 2018 made 2017 seem positively idyllic. It brought an unheard-of global heat wave, with temperatures hitting 108 in Los Angeles, 122 in Pakistan, and 124 in Algeria. In the world’s oceans, six hurricanes and tropical storms appeared on the radars at once, including one, Typhoon Mangkhut, that hit the Philippines and then Hong Kong, killing nearly a hundred and wreaking a billion dollars in damages, and another, Hurricane Florence, which more than doubled the average annual rainfall in North Carolina, killing more than fifty and inflicting $17 billion worth of damage. There were wildfires in Sweden, all the way in the Arctic Circle, and across so much of the American West that half the continent was fighting through smoke, those fires ultimately burning close to 1.5 million acres. Parts of Yosemite National Park were closed, as were parts of Glacier National Park in Montana, where temperatures also topped 100. In 1850, the area had 150 glaciers; today, all but 26 are melted.


Bitcoin. The cryptocurrency now produces as much CO2 each year as a million transatlantic flights.