The Uninhabitable Earth: Life After Warming

by David Wallace-Wells

It is worse, much worse, than you think.

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.

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.

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...

Many perceive global warming as a sort of moral and economic debt, accumulated since the beginning of the Industrial Revolution and ...

more than half of the carbon exhaled into the atmosphere by the burning of fossil fuels has been emitted in just the past three decades. Which means we have done as much damage to the fate of the planet and its ability to sustain human life and civilization since Al Gore published his first ...

this means we have now done as much damage to the environment knowingly as we ever managed in ignorance.

The majority of the burning has come since the premiere of Seinfeld. Since the end of World War II, the figure is about 85 percent.

Wallace Smith Broecker,

Broecker did his research with funding from Exxon,

four degrees is possible, as well—perhaps more. According to some estimates, that would mean that whole regions of Africa and Australia and the United States, parts of South America north of Patagonia, and Asia south of Siberia would be rendered effectively uninhabitable by direct heat, desertification, and flooding.

I am not an environmentalist, and don’t even think of myself as a nature person. I’ve lived my whole life in cities, enjoying gadgets built by industrial supply chains I hardly think twice about. I’ve never gone camping, not willingly anyway, and while I always thought it was basically a good idea to keep streams clean and air clear, I also always accepted the proposition that there was a trade-off between economic growth and cost to nature—and figured, well, in most cases I’d probably go for growth. I’m not about to personally slaughter a cow to eat a hamburger, but I’m also not about to go vegan. I tend to think when you’re at the top of the food chain it’s okay to flaunt it, because I don’t see anything complicated about drawing a moral boundary between us and other animals, and in fact find it offensive to women and people of color that all of a sudden there’s talk of extending human-rights-like legal protections to chimps, apes, and octopuses, just a generation or two after we finally broke the white-male monopoly on legal personhood.

Beginning in 2011, about one million Syrian refugees were unleashed on Europe by a civil war inflamed by climate change and drought—and in a very real sense, much of the “populist moment” the entire West is passing through now is the result of panic produced by the shock of those migrants.

the high end of what’s possible in the next thirty years, the United Nations says, is even worse: “a billion or more vulnerable poor people with little choice but to fight or flee.” A billion or more. That was the entire global population as recently as 1820, with the Industrial Revolution well under way.

the true numbers will almost surely fall short of them, and scientists tend to trust projections in the tens of millions rather than the hundreds of millions.

the optimists have never, in the half century of climate anxiety we’ve already endured, been right.

My file of stories grew daily, but very few of the clips, even those drawn from new research published in the most pedigreed scientific journals, seemed to appear in the coverage about climate change the country watched on television and read in its newspapers.

But the discussion of possible effects was misleadingly narrow, limited almost invariably to the matter of sea-level rise. Just as worrisome, the cov...

the foreign minister of the Marshall Islands offered another name for that level of warming: “genocide.”

There is almost no chance we will avoid that scenario. The Kyoto Protocol achieved, practically, nothing; in the twenty years since, despite all of our climate advocacy and legislation and progress on green energy, we have produced more emissions than in the twenty years before.

In 2016, the Paris accords established two degrees as a global goal, and, to read our newspapers, that level of warming remains something like the scariest scenario it is responsible to consider; just a few years later, with no single industrial nation on track to meet...

yet shrouded, delicately, from public view. For those telling stories about climate, such horrific scenarios—and the fact that we had squandered our chance of landing anywhere on the better half of that curve—had become somehow unseemly to consider. The reasons are almost too many to count, and so half-formed they might better be called impulses. We chose not to discuss a world warmed beyond two degrees out of decency, perhaps; or simple fear; or fear of fearmongering; or technocratic faith, which is really market faith; or deference to partisan debates or even partisan priorities; or skepticism about the environmental Left of the kind I’d always had; or disinterest in the fates of distant ecosystems like I’d also always had.

We suffered from slowness apprehending the speed of change, or semi-conspiratorial confidence in the responsibility of global elites and their institutions, or obeisance toward those elites and their institutions, whatever we thought of them.

Perhaps we felt unable to really trust scarier projections because we’d only just heard about warming, we thought, and things couldn’t possibly have gotten that much worse just since the first Inconvenient Truth; or because we liked driving our cars and eating our beef and living as we did in every other way and didn’t want to think too hard about that;

and because, selfishly, we didn’t mind destroying the planet for others living elsewhere on it or those not yet born who would inherit it from us, outraged. Because we had too much faith in the teleological shape of history and the arrow of human progress to countenance the idea that the arc of history would bend toward anything but environmental justice, too. Because when we were being really honest with ourselves we already thought of the world as a zero-sum resource competition and believed that whatever happened we were probably going to continue to be the victors, relatively speaking anyway, advantages of class being what they are and our own luck in the natalist lottery being what it was.

or perhaps we were also really afraid of robots or were too busy looking at our new phones;

we truly had a good-news bias when it came to the big picture;

But we simply wouldn’t, or couldn’t, or anyway didn’t look squarely in the face of the science.

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.

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 tipping point for that collapse is said to be around two degrees; according to several recent studies, even a rapid cessation of carbon emissions could bring us that amount of warming by the end of the century.

some studying global warming call the hundred years to follow the “century of hell.”

The sea level was there largely because the planet was that much warmer, and the geologic record is the best model we have for understanding the very complicated climate system and gauging just how much damage will come from turning up the temperature by two or four or six degrees.

it is especially concerning that recent research into the deep history of the planet suggests that our current climate models may be underestimating the amount of warming we are due for in 2100 by as much as half.

At two degrees, the ice sheets will begin their collapse,

At four degrees,

In certain places, six climate-driven natural disasters could strike simultaneously, and, globally, damages could pass $600 trillion—more than twice the wealth as exists in the world today.

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.

Nobel laureate William Nordhaus suggests that better-than-anticipated economic growth means better than one-in-three odds that our emissions will exceed the U.N.’s worst-case “business as usual” scenario.

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;

That October, a hurricane in the Pacific wiped Hawaii’s East Island entirely off the map.

We have already exited the state of environmental conditions that allowed the human animal to evolve in the first place, in an unsure and unplanned bet on just what that animal can endure.

It is a function that gets worse over time as long as we continue to produce greenhouse gas.

unless we choose to halt it, it will never stop.

methane, which is thirty-four times as powerful a greenhouse-gas warming blanket as carbon dioxide when judged on the timescale of a century; when judged on the timescale of two decades, it is eighty-six times as powerful.

Warmer oceans can absorb less heat, which means more stays in the air, and contain less oxygen, which is doom for phytoplankton—which does for the ocean what plants do on land, eating carbon and producing oxygen—which leaves us with more carbon, which heats the planet further.

Sea-level rise inundates cropland with more and more saltwater flooding, transforming agricultural areas into brackish sponges no longer able to adequately feed those living off them; flooding power plants, knocking regions offline just as electricity may be needed most; and crippling chemical and nuclear plants, which, malfunctioning, breathe out their toxic plumes.

weaponizing the environment,

This is what is often called the problem of environmental justice; a sharper, less gauzy phrase would be “climate caste system.”