The Uninhabitable Earth: Life After Warming

by David Wallace-Wells

The United Nations’ Intergovernmental Panel on Climate Change (IPCC) offers the gold-standard assessments of the state of the planet and the likely trajectory for climate change—gold-standard, in part, because it is conservative, integrating only new research that passes the threshold of inarguability. A new report is expected in 2022, but the most recent one says that if we take action on emissions soon, instituting immediately all of the commitments made in the Paris accords but nowhere yet actually implemented, we are likely to get about 3.2 degrees of warming, or about three times as much warming as the planet has seen since the beginning of industrialization—bringing the unthinkable collapse of the planet’s ice sheets not just into the realm of the real but into the present. That would eventually flood not just Miami and Dhaka but Shanghai and Hong Kong and a hundred other cities around the world.

The assaults of climate change do not end at 2100 just because most modeling, by convention, sunsets at that point. This is why some studying global warming call the hundred years to follow the “century of hell.”

Hit our Paris emissions targets and we may still get four degrees of warming, meaning a green Sahara and the planet’s tropical forests transformed into fire-dominated savanna.

Because these numbers are so small, we tend to trivialize the differences between them—one, two, four, five. Human experience and memory offer no good analogy for how we should think of those thresholds, but, as with world wars or recurrences of cancer, you don’t want to see even one. At two degrees, the ice sheets will begin their collapse, 400 million more people will suffer from water scarcity, major cities in the equatorial band of the planet will become unlivable, and even in the northern latitudes heat waves will kill thousands each summer. There would be thirty-two times as many extreme heat waves in India, and each would last five times as long, exposing ninety-three times more people. This is our best-case scenario. At three degrees, southern Europe would be in permanent drought, and the average drought in Central America would last nineteen months longer and in the Caribbean twenty-one months longer. In northern Africa, the figure is sixty months longer—five years. The areas burned each year by wildfires would double in the Mediterranean and sextuple, or more, in the United States. At four degrees, there would be eight million more cases of dengue fever each year in Latin America alone and close to annual global food crises. There could be 9 percent more heat-related deaths. Damages from river flooding would grow thirtyfold in Bangladesh, twentyfold in India, and as much as sixtyfold in the United Kingdom. In certain places, six climate-driven natural disasters c...

Even if we pull the planet up short of two degrees by 2100, we will be left with an atmosphere that contains 500 parts per million of carbon—perhaps more. The last time that was the case, sixteen million years ago, the planet was not two degrees warmer; it was somewhere between five and eight, giving the planet about 130 feet of sea-level rise, enough to draw a new American coastline as far west as I-95. Some of these processes take thousands of years to unfold, but they are also irreversible, and therefore effectively permanent. You might hope to simply reverse climate change; you can’t. It will outrun all of us.

By 2100, the United Nations says, we are due for at least three and perhaps more than four degrees of warming, assuming no dramatic change in our emissions. Even with a dramatic change, we are heading past two.

The upper end of the probability curve put forward by the U.N. to estimate the end-of-the-century, high emissions scenario—the worst-case outcome of a worst-case path—puts us at eight degrees. Warming of that level would require a suicidal cocktail of sadistic policy, public indifference, and catastrophic luck. But at eight degrees, humans at the equator and in the tropics would not be able to move around without dying; hardly any land on the planet would be capable of efficiently producing any of the food we now eat; forests would be roiled by rolling storms of fire, and coasts would be punished by more and more intense hurricanes; the suffocating hood of tropical disease would reach northward to enclose parts of what we now call the Arctic; probably about a third of the planet would be made unlivable by direct heat; and what are today literally unprecedented and intolerable droughts and heat waves would be the quotidian condition of whatever human life was able to endure.

A few years ago, E. O. Wilson proposed a term, “Half-Earth,” to help us think through how we might adapt to the pressures of a changing climate, letting nature run its rehabilitative course on half the planet and sequestering humanity in the remaining, habitable half of the world. The fraction may be smaller than that, possibly considerably, and not by choice; the subtitle of his book was Our Planet’s Fight for Life. On longer timescales, the even-bleaker outcome is possible, too—the livable planet darkening as it approaches a human dusk.

To dwell on the more common 500-year figure just for a moment, it would mean a storm that struck once during the entire history of the Roman Empire. Five hundred years ago, there were no English settlements across the Atlantic, so we are talking about a storm that should hit just once as Europeans arrived and established colonies, as colonists fought a revolution and Americans a civil war and two world wars, as their descendants established an empire of cotton on the backs of slaves, freed them, and then brutalized their descendants, industrialized and postindustrialized, triumphed in the Cold War, ushered in the “end of history,” and witnessed, just a decade later, its dramatic return. One storm in all that time, is what the meteorological record has taught us to expect. Just one. Harvey was the third such flood to hit Houston since 2015.

The cleavage is even sharper globally, where the poorest countries will suffer more in our hot new world. In fact, with one exception—Australia—countries with lower GDPs will warm the most. That is notwithstanding the fact that much of the global south has not, to this point, defiled the atmosphere of the planet all that much. This is one of the many historical ironies of climate change that would better be called cruelties, so merciless is the suffering they will inflict. But disproportionately as it will fall on the world’s least, the devastation of global warming cannot be easily quarantined in the developing world, as much as those in the Northern Hemisphere would probably, and not to our credit, prefer it. Climate disaster is too indiscriminate for that.

Climate change could soon mean that, in the fall, trees may simply turn brown, and so we will look differently at entire schools of painting, which stretched for generations, devoted to best capturing the oranges and reds we can no longer see ourselves out the windows of our cars as we drive along our highways. The coffee plants of Latin America will no longer produce fruit; beach homes will be built on higher and higher stilts and still be drowned. In many cases, it is better to use the present tense. In just the last forty years, according to the World Wildlife Fund, more than half of the world’s vertebrate animals have died; in just the last twenty-five, one study of German nature preserves found, the flying insect population declined by three-quarters. Species individuated over millions of years of evolution but forced together by climate change have begun to mate with one another for the first time, producing a whole new class of hybrid species: the pizzly bear, the coy-wolf. The zoos are already natural history museums, the children’s books already out of date.

Older fables, too, will be remade: the story of Atlantis, having endured and enchanted for several millennia, will compete with the real-time sagas of the Marshall Islands and Miami Beach, each sinking over time into snorkelers’ paradises; the strange fantasy of Santa and his polar workshop will grow eerier still in an Arctic of ice-free summers; and there is a terrible poignancy in contemplating how desertification of the entire Mediterranean Basin will change our reading of the Odyssey, or how it will discolor the shine of Greek islands for dust from the Sahara to permanently blanket their skies, or how it will recast the meaning of the Pyramids for the Nile to be dramatically drained. We will think of the border with Mexico differently, presumably, when the Rio Grande is a line traced through a dry riverbed—the Rio Sand, it’s already been called. The imperious West has spent five centuries looking down its nose at the plight of those living within the pale of tropical disease, and one wonders how that will change when mosquitoes carrying malaria and dengue are flying through the streets of Copenhagen and Chicago, too.

Eight hundred million in South Asia alone, the World Bank says, would see their living conditions sharply diminish by 2050 on the current emissions track, and perhaps a climate slowdown will even reveal the bounty of what Andreas Malm calls fossil capitalism to be an illusion, sustained over just a few centuries by the arithmetic of adding the energy value of burned fossil fuels to what had been, before wood and coal and oil, an eternal Malthusian trap. In which case, we would have to retire the intuition that history will inevitably extract material progress from the planet, at least in any reliable or global pattern, and come to terms, somehow, with just how pervasively that intuition ruled even our inner lives, often tyrannically.

Every degree of warming, it’s been estimated, costs a temperate country like the United States about one percentage point of GDP, and according to one recent paper, at 1.5 degrees the world would be $20 trillion richer than at 2 degrees. Turn the dial up another degree or two, and the costs balloon—the compound interest of environmental catastrophe. 3.7 degrees of warming would produce $551 trillion in damages, according to at least one estimate—almost double the amount of wealth that exists in the world today. Multiply four degrees by that 1 percent of GDP and you have almost entirely wiped out the very possibility of economic growth, which has not topped 5 percent globally in over forty years.

In the journal Nature Climate Change, a team led by Drew Shindell tried to quantify the suffering that would be avoided if warming was kept to 1.5 degrees, rather than 2 degrees—in other words, how much additional suffering would result from just that additional half-degree of warming. Their answer: 150 million more people would die from air pollution alone in a 2-degree warmer world than in a 1.5-degree warmer one. Later that year, the IPCC raised the stakes further: in the gap between 1.5 degrees and 2, it said, hundreds of millions of lives were at stake. Numbers that large can be hard to grasp, but 150 million is the equivalent of twenty-five Holocausts. It is three times the size of the death toll of the Great Leap Forward—the largest nonmilitary death toll humanity has ever produced. It is more than twice the greatest death toll of any kind, World War II. The numbers don’t begin to climb only when we hit 1.5 degrees, of course. As should not surprise you, they are already accumulating, at a rate of at least seven million deaths, from air pollution alone, each year—an annual Holocaust, pursued and prosecuted by what brand of nihilism?

I’ve also often been asked whether it’s moral to reproduce in this climate, whether it’s responsible to have children, whether it is fair to the planet or, perhaps more important, to the children. As it happens, in the course of writing this book, I did have a child, Rocca. Part of that choice was climate delusion, that same willful blindness: I know there are horrors to come, some of which will inevitably be visited on my children—that is what it means for warming to be an all-encompassing, all-touching threat. Part of it was climate privilege: knowing the horrors will be less intense for some parts of the world than others.

Smug white liberal prick. I wonder if he's come to regret his decision post-COVID/inflation.

Especially those who have imbibed several centuries of Western triumphalism tend to see the story of human civilization as an inevitable conquest of the earth, rather than the saga of an insecure culture, like mold, growing haphazardly and unsurely upon it. That fragility, which pervades now everything humans might do on this planet, is the great existential insight of global warming, but it is only beginning to shake our triumphalism—though, if we had stopped to contemplate the possibilities a generation ago, it probably would not surprise us to see a new form of political nihilism emerging in the region of the world already baked hardest by global warming, the Middle East, and expressed there through suicidal spasms of theological violence. That region was once called, grandly, “the cradle of civilization.” Today, political nihilism radiates almost everywhere, through the many cultures that arose, branching, from Middle Eastern roots.

The science that makes up the following twelve chapters has been culled from interviews with dozens of experts, and from hundreds of papers published in the best academic journals over the previous decade or so. Since it is science, it is tentative, ever-evolving, and some of the predictions that follow will surely not come precisely to pass. Since the most recent IPCC report, much of that evolving work has focused on climate impacts arising from a high-emissions scenario, one producing four or five degrees of warming by the end of this century. But while those projections may well prove more extreme than the world we find ourselves inhabiting in 2100, the chapters that follow represent an honest and fair portrait of the state of our collective understanding of the many multiplying threats that a warming planet poses to all of us presently living on it, and hoping we may continue to do so, in an indefinite and undisturbed way.

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, any time at all 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.” Five or six degrees is unlikely by 2100. But at just two degrees, cities now home to millions, across India and the Middle East, would become so hot that stepping outside in summer would be a lethal risk, and wildfires already terrifying anyone living in the American West would burn at least four times as much land. The sea level rise made inevitable by that amount of warming would, over centuries, flood or drown hundreds of major cities.

Since 1980, the planet has experienced a fiftyfold increase in the number of dangerous heat waves; a bigger increase is to come. The five warmest summers in Europe since 1500 have all occurred since 2002, and eventually, the IPCC warns, simply working outdoors at that time of year will be unhealthy for parts of the globe. Even if we meet the Paris goals, cities like Karachi and Kolkata will annually encounter deadly heat waves like those that crippled them in 2015, when heat killed thousands in India and Pakistan. At four degrees, the deadly European heat wave of 2003, which killed as many as 2,000 people a day, will be a normal summer.

In 2018, the hottest temperature likely ever recorded in April was registered in southeast Pakistan. In India, a single day over 95 degrees Fahrenheit increases annual mortality rates by three-quarters of a percent; in 2016, a string of days topped 120—in May. In Saudi Arabia, where summer temperatures often approach that mark, 700,000 barrels of oil are burned each day in the summer, mostly to power the nation’s air-conditioning. That can help with the heat, of course, but air conditioners and fans already account for fully 10 percent of global electricity consumption.

In the sugarcane region of El Salvador, as much as one-fifth of the population—including over a quarter of the men—has chronic kidney disease, the presumed result of dehydration from working the fields they were able to comfortably harvest as recently as two decades ago. With dialysis, which is expensive, those with kidney failure can expect to live five years; without it, life expectancy is measured in weeks.

How much hotter will it get? The question may sound scientific, inviting expertise, but the answer is almost entirely human—which is to say, political. The menace of climate change is a mercurial one; uncertainty makes it a shape-shifting threat. When will the planet warm by two degrees, and when by three? How much sea-level rise will be here by 2030, by 2050, by 2100, as our children are leaving the earth to their children and grandchildren? Which cities will flood, which forests will dry out, which breadbaskets will become husks?

It was as recent as 2016 that the celebrated Paris climate accords were adopted—defining two degrees of global warming as a must-meet target and rallying all the world’s nations to meet it—and the returns are already dispiritingly grim. In 2017, carbon emissions grew by 1.4 percent, according to the International Energy Agency, after an ambiguous couple of years optimists had hoped represented a leveling-off, or peak; instead, we’re climbing again. Even before the new spike, not a single major industrial nation was on track to fulfill the commitments it made in the Paris treaty. Of course, those commitments only get us down to 3.2 degrees; to keep the planet under 2 degrees of warming, all signatory nations have to significantly better their pledges. At present, there are 195 signatories, of which only the following are considered even “in range” of their Paris targets: Morocco, Gambia, Bhutan, Costa Rica, Ethiopia, India, and the Philippines. This puts Donald Trump’s commitment to withdraw from the treaty in a useful perspective; in fact, his spite may ultimately prove perversely productive, since the evacuation of American leadership on climate seems to have mobilized China—giving Xi Jinping an opportunity and an enticement to adopt a much more aggressive posture toward climate. Of course those renewed Chinese commitments are, at this point, just rhetorical, too; the country already has the world’s largest footprint, and in the first three months of 2018 its emissions gr...

One estimate suggests that, to have hopes of two degrees, we need to open new full-scale carbon capture plants at the pace of one and a half per day every day for the next seventy years. In 2018, the world had eighteen of them, total.

Cities, where the world will overwhelmingly live in the near future, only magnify the problem of high temperature. Asphalt and concrete and everything else that makes a city dense, including human flesh, absorb ambient heat, essentially storing it for a time like a slow-release poison pill; this is especially problematic because, in a heat wave, nightly reprieves are vital, allowing bodies to recover. When those reprieves are shorter, and shallower, flesh simply continues to simmer. In fact, the concrete and asphalt of cities absorb so much heat during the day that when it is released, at night, it can raise the local temperature as much as 22 degrees Fahrenheit, turning what could be bearably hot days into deadly ones—as in the Chicago heat wave of 1995, which killed 739 people, the direct-heat effects compounded by broken public health infrastructure. That commonly cited figure only reflects immediate deaths; of the many thousands more who visited hospitals during the heat wave, almost half died within the year. Others merely suffered permanent brain damage. Scientists call this the “heat island” effect—each city its own enclosed space, and hotter the more crowded it is.

Already, as many as 1 billion are at risk for heat stress worldwide, and a third of the world’s population is subject to deadly heat waves at least twenty days each year; by 2100, that third will grow to half, even if we manage to pull up short of two degrees. If we don’t, the number could climb to three-quarters.

Climates differ and plants vary, but the basic rule of thumb for staple cereal crops grown at optimal temperature is that for every degree of warming, yields decline by 10 percent. Some estimates run higher. Which means that if the planet is four degrees warmer at the end of the century, when projections suggest we may have as many as 50 percent more people to feed, we may also have 50 percent less grain to give them. Or even less, because yields actually decline faster the warmer things get. And proteins are worse: it takes eight pounds of grain to produce just a single pound of hamburger meat, butchered from a cow that spent its life warming the planet with methane burps. Globally, grain accounts for about 40 percent of the human diet; when you add soybeans and corn, you get up to two-thirds of all human calories. Overall, the United Nations estimates that the planet will need nearly twice as much food in 2050 as it does today—and although this is a speculative figure, it’s not a bad one.

The world’s natural wheat belt is moving poleward by about 160 miles each decade, but you can’t easily move croplands north a few hundred miles, and not just because it’s difficult to suddenly clear the land occupied now by towns, highways, office parks, and industrial installations. Yields in places like remote areas of Canada and Russia, even if they warmed by a few degrees, would be limited by the quality of soil there, since it takes many centuries for the planet to produce optimally fertile dirt. The lands that are fertile are the ones we are already using, and the climate is changing much too fast to wait for the northern soil to catch up. That soil, believe it or not, is literally disappearing—75 billion tons of soil lost each year. In the United States, the rate of erosion is ten times as high as the natural replenishment rate; in China and India, it is thirty to forty times as fast.

It may yet be a bit early to judge Ehrlich—or perhaps even his godfather, Malthus—since nearly all of the astonishing productivity gains of the last century trace back to the work of a single man, Norman Borlaug, perhaps the best argument for the humanitarian virtue of America’s imperial century. Born to Iowa family farmers in 1914, he went to state school, found work at DuPont, and then, with the help of the Rockefeller Foundation, developed a new collection of high-yield, disease-resistant wheat varieties that are now credited with saving the lives of a billion people worldwide. Of course, if those gains were a onetime boost—engineered, in large part, by a single man—how comfortably can we count on future improvements?

Not only is it undeniably the case that the cruelest impacts of climate change will be borne by those least resilient in the face of climate tragedy, but to a large degree what could be called the humanitarian growth of the developing world’s middle class since the end of the Cold War has been paid for by fossil-fuel-driven industrialization—an investment in the well-being of the global south made by mortgaging the ecological future of the planet.

This is one reason that our global climate fate will be shaped so overwhelmingly by the development patterns of China and India, who have the tragic burden of trying to bring many hundreds of millions more into the global middle class while knowing that the easy paths taken by the nations that industrialized in the nineteenth and even twentieth centuries are now paths to climate chaos. Which is not to say they won’t follow them anyway: by 2050, milk consumption in China is expected to grow to triple the current level, thanks to the changing, West-facing tastes of its emerging consumer classes, a single-item boom in a single country that is expected, all by itself, to increase global greenhouse-gas emissions from dairy farming by about 35 percent.

And turning away from milk is one thing; turning down cheap electrification, automobile culture, or the protein-heavy diets the world’s wealthy rely on to stay thin are much bigger asks. In the postindustrial West, we try not to think about these bargains, which have benefited us so enormously. When we do, it is often in the guilty spirit of what critic Kris Bartkus has memorably called “the Malthusian tragic”—namely, our inability to see any remaining innocence in the quotidian life of the well-to-do West, given the devastation that wealth has imposed on the world of natural wonder it conquered and the suffering of those, elsewhere on the planet, left behind in the race to endless material comforts. And asked, functionally, to pay for them.

Drought may be an even bigger problem for food production than heat, with some of the world’s most arable land turning quickly to desert. At 2 degrees of warming, droughts will wallop the Mediterranean and much of India, and corn and sorghum all around the world will suffer, straining global food supply. At 2.5 degrees, thanks mostly to drought, the world could enter a global food deficit—needing more calories than the planet can produce. At 3 degrees, there would be further drought—in Central America, Pakistan, the western United States, and Australia. At 5 degrees, the whole earth would be wrapped in what the environmentalist Mark Lynas calls “two globe-girdling belts of perennial drought.”

By 2080, without dramatic reductions in emissions, southern Europe will be in permanent extreme drought, much worse than the American Dust Bowl ever was. The same will be true in Iraq and Syria and much of the rest of the Middle East; some of the most densely populated parts of Australia, Africa, and South America; and the breadbasket regions of China. None of these places, which today supply much of the world’s food, would be reliable sources going forward.

Remember, even with the remarkable gains of the last decades, we do not presently live in a world without hunger. Far from it: most estimates put the number of undernourished at 800 million globally, with as many as 100 million hungry because of climate shocks. What is called “hidden hunger”—micronutrient and dietary deficiencies—is considerably higher, affecting well over 1 billion people. The spring of 2017 brought an unprecedented quadruple famine to Africa and the Middle East; the United Nations warned that those separate starvation events in Somalia, South Sudan, Nigeria, and Yemen could kill 20 million that year. That was a single year in a single region. Africa is today straining to feed about 1 billion people, a population expected to quadruple over the course of the twenty-first century to 4 billion.

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.

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.

In 2014, we learned that the West Antarctic and Greenland ice sheets were even more vulnerable to melting than scientists anticipated—in fact, the West Antarctic sheet had already passed a tipping point of collapse, more than doubling its rate of ice loss in just five years. The same had happened in Greenland, where the ice sheet is now losing almost a billion tons of ice every single day. The two sheets contain enough ice to raise global sea levels ten to twenty feet—each. In 2017, it was revealed that two glaciers in the East Antarctic sheet were also losing ice at an alarming rate—eighteen billion tons of ice each year, enough to cover New Jersey in three feet of ice. If both glaciers go, scientists expect, ultimately, an additional 16 feet of water. In total, the two Antarctic ice sheets could raise sea level by 200 feet; in many parts of the world, the shoreline would move by many miles. The last time the earth was four degrees warmer, as Peter Brannen has written, there was no ice at either pole and sea level was 260 feet higher. There were palm trees in the Arctic. Better not to think what that means for life at the equator.

The most recent IPCC assessment projects a loss of near-surface permafrost of between 37 and 81 percent by 2100, though most scientists still believe that carbon will be released slowly, and mostly as less-terrifying carbon dioxide. But as far back as 2011, NOAA and the National Snow and Ice Data Center predicted that thawing permafrost would flip the whole region from being what is called a carbon sink, which absorbs atmospheric carbon, to a carbon source, which releases carbon, as quickly as the 2020s. By 2100, the same study said, the Arctic could release a hundred billion tons of carbon. That is the equivalent of half of all the carbon produced by humanity since industrialization began.

Remember, that is the Arctic feedback loop that does not much concern many climate scientists in the near term. The one that concerns them more, at present, is what is called the “albedo effect”: ice is white and so reflects sunlight back into space rather than absorbing it; the less ice, the more sunlight is absorbed as global warming; and the total disappearance of that ice, Peter Wadhams has estimated, could mean a massive warming equivalent to the entire last twenty-five years of global carbon emissions. The last twenty-five years of emissions, keep in mind, is about half of the total that humanity has ever produced—a scale of carbon production that has pushed the planet from near-complete climate stability to the brink of chaos.

What is coming? Much more fire, much more often, burning much more land. Over the last five decades, the wildfire season in the western United States has already grown by two and a half months; of the ten years with the most wildfire activity on record, nine have occurred since 2000. Globally, since just 1979, the season has grown by nearly 20 percent, and American wildfires now burn twice as much land as they did as recently as 1970. By 2050, destruction from wildfires is expected to double again, and in some places within the United States the area burned could grow fivefold. For every additional degree of global warming, it could quadruple. What this means is that at three degrees of warming, our likely benchmark for the end of the century, the United States might be dealing with sixteen times as much devastation from fire as we are today, when in a single year ten million acres were burned. At four degrees of warming, the fire season would be four times worse still. The California fire captain believes the term is already outdated: “We don’t even call it fire season anymore,” he said in 2017. “Take the ‘season’ out—it’s year-round.”

At present, the trees of the Amazon take in a quarter of all the carbon absorbed by the planet’s forests each year. But in 2018, Jair Bolsonaro was elected president of Brazil promising to open the rain forest to development—which is to say, deforestation. How much damage can one person do to the planet? A group of Brazilian scientists has estimated that between 2021 and 2030, Bolsonaro’s deforestation would release the equivalent of 13.12 gigatons of carbon. Last year, the United States emitted about 5 gigatons. This means that this one policy would have between two and three times the annual carbon impact of the entire American economy, with all of its airplanes and automobiles and coal plants. The world’s worst emitter, by far, is China; the country was responsible for 9.1 gigatons of emissions in 2017. This means Bolsonaro’s policy is the equivalent of adding, if just for a year, a whole second China to the planet’s fossil fuel problem—and, on top of that, a whole second United States.

The ability of forest soils to absorb methane has fallen by 77 percent in just three decades, and some of those studying the rate of tropical deforestation believe it could deliver an additional 1.5 degrees Celsius of global warming even if fossil fuel emissions immediately ceased.

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.

And in the future, all that was once unprecedented becomes quickly routine. Remember Hurricane Sandy? By 2100, floods of that scale could arrive seventeen times more often in New York. Katrina-level hurricanes are expected to double in frequency. Looking globally, researchers have found an increase of 25 to 30 percent in Category 4 and 5 hurricanes for just one degree Celsius of global warming. Between just 2006 and 2013, the Philippines were hit by seventy-five natural disasters; over the last four decades in Asia, typhoons have intensified by between 12 and 15 percent, and the proportion of Category 4 and 5 storms has doubled; in some areas, it has tripled. By 2070, Asian megacities could lose as much as $35 trillion in assets due to storms, up from just $3 trillion in 2005.

Half of the world’s population depends on seasonal melt from high-elevation snow and ice, deposits that are dramatically threatened by warming. Even if we hit the Paris targets, the glaciers of the Himalayas will lose 40 percent of their ice by 2100, or possibly more, and there could be widespread water shortages in Peru and California, the result of glacier melt. At four degrees, the snow-capped Alps could look more like Morocco’s Atlas Mountains, with 70 percent less snow by the end of the century. As soon as 2020, as many as 250 million Africans could face water shortages due to climate change; by the 2050s, the number could hit a billion people in Asia alone. By the same year, the World Bank found, freshwater availability in cities around the world could decline by as much as two-thirds. Overall, according to the United Nations, five billion people could have poor access to freshwater by 2050.

In the last hundred years, many of the planet’s largest lakes have begun drying up, from the Aral Sea in central Asia, which was once the world’s fourth largest and which has lost more than 90 percent of its volume in recent decades, to Lake Mead, which supplies much of Las Vegas’s water and has lost as much as 400 billion gallons in a single year. Lake Poopó, once Bolivia’s second biggest, has completely disappeared; Iran’s Lake Urmia has shrunk more than 80 percent in thirty years. Lake Chad has more or less evaporated entirely.

We’re already racing, as a short-term fix for the world’s drought boom, to drain underground water deposits known as aquifers, but those deposits took millions of years to accumulate and aren’t coming back anytime soon. In the United States, aquifers already supply a fifth of our water needs; as Brian Clark Howard has noted, wells that used to draw water at 500 feet now require pumps at least twice as deep. The Colorado River Basin, which serves water to seven states, lost twelve cubic miles of groundwater between 2004 and 2013; the Ogallala Aquifer in part of the Texas Panhandle lost 15 feet in a decade, and is expected to drain by 70 percent over the next fifty years in Kansas. In the meantime, they’re fracking in that drinking water. In India, in just the next two years, twenty-one cities could exhaust their groundwater supply.

When it comes to freshwater, the bigger picture is this: personal consumption amounts to such a thin sliver that only in the most extreme droughts can it even make a difference. Even before the drought, one estimate found that South Africa had nine million people without any access to water for personal consumption at all; the amount of water required to satisfy the needs of those millions is only about one-third the amount of water used, each year, to produce the nation’s wine crop. In California, where droughts are punctuated by outrage over pools and ever-green lawns, total urban consumption accounts for only 10 percent.