The Uninhabitable Earth: Life After Warming

by David Wallace-Wells

According to one analysis, if the world as a whole followed the Chinese example, it would bring five degrees of warming by 2100.

In 2018, the United Nations predicted that at the current emissions rate the world would pass 1.5 degrees by 2040, if not sooner;

according to the 2017 National Climate Assessment, even if global carbon concentration was immediately stabilized, we should expect more than half a deg...

These tools come in two forms: technologies that would suck carbon out of the air and new approaches to forestry and agriculture that would allow plant life to do the same,

According to a raft of recent papers, both are something close to fantasy, at least at present. In 2018, the European Academies’ Science Advisory Council found that existing negative-emissions technologies have “limited realistic potential” to even slow the increase in concentration of carbon in

the atmosphere—let alone meaningfully reduce that concentration. In 2018, Nature dismissed all scenarios built on carbon capture as “magical thinking.”

so relying on carbon capture globally could require large-scale scrubbing plantations nearly everywhere on Earth—the planet transformed into something like an air-recycling plant orbiting the sun, an industrial satellite tracing a parabola through the solar system.

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.

there is also some risk from scientific uncertainty, the possibility that we are underestimating the effects of those feedback loops in natural systems we only poorly understand.

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

Climate change won’t likely slow that pattern by much, but it will make the great migrations it reflects more perilous, with many millions of the world’s ambitious flooding into cities whose calendars are dotted with days of deadly heat, gathering in those new megalopolises like moths to a flame.

Currently, there are 354 major cities with average maximum summertime temperatures of 95 degrees Fahrenheit or higher.

By 2050, that list could grow to 970,

First comes “heat exhaustion,” mostly a mark of dehydration: profuse sweating, nausea, headache. After a certain point, though, water won’t help, your core temperature rising as your body sends blood outward to the skin, hoping desperately to cool it down. The skin often reddens; internal organs begin to fail. Eventually you could stop sweating. The brain, too, stops working properly, and sometimes, after a period of agitation and combativeness, the episode is punctuated with a lethal heart attack.

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.

the tropics are already too hot to efficiently grow grain, and those places where grain is produced today are already at optimal growing temperature—which means even a small warming will push them down a slope of declining productivity.

A decade ago, climatologists might have told you that although direct heat undermined plant growth, the extra carbon in the atmosphere would have the opposite effect—a kind of airborne fertilizer. The effect is strongest on weeds, though, and does not seem to hold for grain.

at higher concentrations of carbon, plants grow thicker leaves, which sounds innocuous. But thicker leaves are worse at absorbing CO2, an effect that means, by the end of the century, as much as 6.39 billion additional tons in the atmosphere each year.

Beyond carbon, climate change means staple crops are doing battle with more insects—their increased activity could cut yields an additional 2 to 4 percent—as well as...

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.

John Wesley Powell,

divined a natural boundary running due north along the 100th meridian. It separated the humid—and therefore cultivatable—natural farmland of what became the Midwest from the arid, spectacular, but less farmable land of the true West.

Since just 1980, that boundary has moved fully 140 miles east, almost to the 98th parallel, drying up hundreds of thousands of square miles of farmland in the process. The planet’s only other similar boundary is the one separating the Sahara desert from the rest of Africa. That desert has expanded by 10 percent, too; in the winter, the figure is 18 percent.

The privileged children of the industrialized West have long laughed at the predictions of Thomas Malthus, the British economist who believed that long-term economic growth was impossible, since each bumper crop or episode of growth would ultimately produce more children to consume or absorb it—and as a result the size of any population, including that of the planet as a whole, was a check against material well-being.

it is one thing to consider what might be the maximum yield of a particular plot of earth and another to contemplate how fully that number is governed by environmental systems—systems far larger and more diffusely determined than even an imperial wizard like Borlaug could reasonably expect to command and control.

The graphs that show so much recent progress in the developing world—on poverty, on hunger, on education and infant mortality and life expectancy and gender relations and more—are, practically speaking, the same graphs that trace the dramatic rise in global carbon emissions that has brought the planet to the brink of overall catastrophe.

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.

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.

avoid dangerous climate change, Greenpeace has estimated that the world needs to cut its meat and dairy consumption in half by 2050;

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. Of course, most have not embraced that tragic, or self-pitying, view. A state of half-ignorance and half-indifference is a much more pervasive climate sickness than true denial or true fatalism.

“A crime is something someone else commits,” from Steinbeck—like

“Someday, perhaps not long from now, the inhabitants of a hotter, more dangerous and biologically diminished planet than the one on which I lived may wonder what you and I were thinking, or whether we thought at all.” For much of the book’s prologue, he writes in a past tense rendered from an imagined, devastated future. “Of course we did it to ourselves; we had always been intellectually lazy, and the less asked of us, the less we had to say,” he writes. “We all lived for money, and that is what we died for.”

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.

the droughts in the American plains and Southwest would not just be worse than in the 1930s, a 2015 NASA study predicted, but worse than any droughts in a thousand years—and that includes those that struck between 1100 and 1300, which dried up all the rivers east of the Sierra Nevada mountains and may have been responsible for the death of the Anasazi civilization.

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, affecti...

China has invested in truly customized farming strategies to boost productivity and cut the use of greenhouse-gas-producing fertilizer;

in Britain, a “soil-free startup” announced its first “harvest” in 2018; in the United States, you already hear about the prospects for vertical farming, which saves farmland by stacking crops indoors; and lab-grown protein, which does the same by culturing meats inside test tubes.

A decade ago, there was great optimism that GMO crops could produce another green revolution, but today gene modification has been used mostly to make plants more resistant to pesticides,

“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.

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.

That the sea will become a killer is a given. Barring a reduction of emissions, we could see at least four feet of sea-level rise and possibly eight by the end of the century.

so focused on sea-level rise that it has blinded readers to all the climate scourges beyond the oceans that threaten to terrorize the coming generations—direct heat, extreme weather, pandemic disease, and more.

That so many feel already acclimated to the prospect of a near-future world with dramatically higher oceans should be as dispiriting and disconcerting as if we’d already come to accept the inevitability of extended nuclear war—because that is the scale of devastation the rising oceans will unleash.

Jakarta is one of the world’s fastest-growing cities, today home to ten million; thanks to flooding and literal sinking, it could be entirely underwater as soon as 2050.

will take thousands of years, perhaps millions, for quartz and feldspar to degrade into sand that might replenish the beaches we lose.