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Unbreathable Air

Our lungs need oxygen, but it is only a fraction of what we breathe, and the fraction tends to decline the more carbon is in the atmosphere. That doesn’t mean we are at risk of suffocation—oxygen is far too abundant for that—but we will nevertheless suffer. With CO2 at 930 parts per million (more than double where we are today), cognitive ability declines by 21 percent.

The effects are more pronounced indoors, where CO2 tends to build up—that’s one reason you probably feel a little more awake when taking a brisk walk outside than you do after spending a long day inside with the windows closed. And it’s also a reason elementary school classrooms have been found, by one study, to already average 1,000 parts per million, with almost a quarter of those surveyed in Texas over 3,000—quite alarming numbers, given that these are the environments we’ve designed to promote intellectual performance. But classrooms are not the worst offenders: other studies have shown even higher concentrations on airplanes, with effects you can probably groggily recall from past experience.

But carbon is, more or less, the least of it. Going forward, the planet’s air won’t just be warmer; it will likely also be dirtier, more oppressive, and more sickening. Droughts have a direct impact on air quality, producing what is now known as dust exposure and in the days of the American Dust Bowl was called “dust pneumonia”; climate change will bring new dust storms to those plains states, where deaths from dust pollution are expected to more than double and hospitalizations to triple. The hotter the planet gets, the more ozone forms, and by the middle of this century Americans should suffer a 70 percent increase in days with unhealthy ozone smog, the National Center for Atmospheric Research has projected. By the 2090s, as many as 2 billion people globally will be breathing air above the WHO “safe” level. Already, more than 10,000 people die from air pollution daily. That is considerably more each day—each day—than the total number of people who have ever been affected by the meltdowns of nuclear reactors. This is not a slam-dunk argument in favor of nuclear power, of course, since the comparison isn’t so neat: there are many, many more fossil fuel chimneys disgorging their trails of black smoke than fission facilities with their finger-trap towers and clouds of white vapor. But it is a startling mark of just how all-encompassing our regime of carbon pollution really is, enclosing the planet in a toxic swaddle.

In recent years, researchers have uncovered a whole secret history of adversity woven into the experience of the last half century by the hand of leaded gasoline and lead paint, which seem to have dramatically increased rates of intellectual disability and criminality, and dramatically decreased educational attainment and lifetime earnings, wherever they were introduced. The effects of air pollution seem starker already. Small-particulate pollution, for instance, lowers cognitive performance over time so much that researchers call the effect “huge”: reducing Chinese pollution to the EPA standard, for instance, would improve the country’s verbal test scores by 13 percent and its math scores by 8 percent. (Simple temperature rise has a robust and negative impact on test taking, too: scores go down when it’s hotter out.) Pollution has been linked with increased mental illness in children and the likelihood of dementia in adults. A higher pollution level in the year a baby is born has been shown to reduce earnings and labor force participation at age thirty, and the relationship of pollution to premature births and low birth weight of babies is so strong that the simple introduction of E-ZPass in American cities reduced both problems, in the vicinity of toll plazas, by 10.8 percent and 11.8 percent, respectively, just by cutting down on the exhaust expelled when cars slowed to pay the toll.

Then there is the more familiar health threat from pollution. In 2013, melting Arctic ice remodeled Asian weather patterns, depriving industrial China of the natural wind-ventilation patterns it had come to depend on, and, as a result, blanketing much of the country’s north in an unbreathable smog. An obtuse-seeming metric called the Air Quality Index categorizes the risks according to an idiosyncratic unit scale tabulating the presence of a variety of pollutants: the warnings begin at 51–100, and at 201–300 include promises of “significant increase in respiratory effects in the general population.” The index tops out with the 301–500 range, warning of “serious aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly” and “serious risk of respiratory effects in the general population”; at that level, “everyone should avoid all outdoor exertion.” The Chinese “airpocalypse” of 2013 doubled the high end of that upper range, reaching a peak Air Quality Index of 993, and scientists studying the phenomenon suggested that China had inadvertently invented an entirely new and unstudied kind of smog, one that combined the “pea soup” pollution of industrial-era Europe and the small-particulate pollution that has lately contaminated so much of the developing world. That year, smog was responsible for 1.37 million deaths in the country.

Outside of China, most saw the photographs and video of a world capital blanketed by gray so thick it blotted out the sun as a sign, not of the state of the planet’s atmosphere, but of just how backward that one country was—just how far China lagged behind the quality-of-life indices of the first world, whatever its rapid economic growth suggested about its place in the global pecking order. Then, in the record California wildfire season of 2017, the air around San Francisco was worse than on the same day in Beijing. In Napa, the Air Quality Index hit 486. In Los Angeles, there was a run on surgical masks; in Santa Barbara, residents scooped ash from their drainpipes by the handful. In Seattle, the following year, wildfire smoke made it unsafe for anyone, anywhere, to breathe outside. Which gave Americans one more reason—panic about their own health—to look away from the situation in Delhi, where in 2017 the Air Quality Index reached 999.

The Indian capital is home to 26 million people. In 2017, simply breathing its air was the equivalent of smoking more than two packs of cigarettes a day, and local hospitals saw a patient surge of 20 percent. Runners in Delhi’s half marathon competed with their heads wrapped by white masks. And air that thick with smut is hazardous in other ways: visibility was so low that cars crashed in pileups on Delhi’s highways, and United canceled flights in and out of the city.

New research shows that even short-term exposure to particulate pollution can dramatically increase rates of respiratory infections, with every additional ten micrograms per cubic meter associated with a rise in diagnoses between 15 and 32 percent. Blood pressure goes up, too. In 2017, The Lancet reported, nine million premature deaths globally were from small-particulate pollution; more than a quarter were in India. And that was before final figures were in from that year’s spike.

In Delhi, much of the pollution comes from the burning of nearby farmland; but elsewhere small-particulate smog is produced primarily by diesel and gas exhaust and other industrial activity. The public health damage is indiscriminate, touching nearly every human vulnerability: pollution increases prevalence of stroke, heart disease, cancer of all kinds, acute and chronic respiratory diseases like asthma, and adverse pregnancy outcomes, including premature birth. New research into the behavioral and developmental effects is perhaps even scarier: air pollution has been linked to worse memory, attention, and vocabulary, and to ADHD and autism spectrum disorders. Pollution has been shown to damage the development of neurons in the brain, and proximity to a coal plant can deform your DNA.

In the developing world, 98 percent of cities are enveloped by air above the threshold of safety established by the WHO. Get out of urban areas and the problem doesn’t much improve: 95 percent of the world’s population is breathing dangerously polluted air. Since 2013, China has undertaken an unprecedented cleanup of its air, but as of 2015 pollution was still killing more than a million Chinese each year. Globally, one out of six deaths is caused by air pollution.

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Pollution like this isn’t news in any meaningful sense; you can find omens about the toxicity of smog and the dangers of blackened air, for instance, in the writing of Charles Dickens, rarely appreciated as an environmentalist. But every year we are discovering more and more ways in which our industrial activity is poisoning the planet.

One particular note of alarm has been struck by what seems like an entirely new—or newly understood—pollution threat: microplastics. Global warming did not bring us microplastics in any direct way, and yet their rapid conquest of our natural world has become an irresistible fable about just what kind of transformation is meant by the word “Anthropocene,” and just how much the world’s booming consumer culture is to blame.

Environmentalists probably know already about “the Great Pacific garbage patch”—that mass of plastic, twice the size of Texas, floating freely in the Pacific Ocean. It is not actually an island—in fact, it is not actually a stable mass, only rhetorically convenient for us to think of it that way. And it is mostly composed of larger-scale plastics, of the kind visible to the human eye. The microscopic bits—700,000 of them can be released into the surrounding environment by a single washing-machine cycle—are more insidious. And, believe it or not, more pervasive: a quarter of fish sold in Indonesia and California contain plastics, according to one recent study. European eaters of shellfish, one estimate has suggested, consume at least 11,000 bits each year.

The direct effect on ocean life is even more striking. The total number of marine species said to be adversely affected by plastic pollution has risen from 260 in 1995, when the first assessment was carried out, to 690 in 2015 and 1,450 in 2018. A majority of fish tested in the Great Lakes contained microplastics, as did the guts of 73 percent of fish surveyed in the northwest Atlantic. One U.K. supermarket study found that every 100 grams of mussels were infested with 70 particles of plastic. Some fish have learned to eat plastic, and certain species of krill are now functioning as plastic processing plants, churning microplastics into smaller bits that scientists are now calling “nanoplastics.” But krill can’t grind it all down; in one square mile of water near Toronto, 3.4 million microplastic particles were recently trawled. Of course, seabirds are not immune: one researcher found 225 pieces of plastic in the stomach of a single three-month-old chick, weighing 10 percent of its body mass—the equivalent of an average human carrying about ten to twenty pounds of plastic in a distended belly. (“Imagine having to take your first flight out to sea with all that in your stomach,” the researcher told the Financial Times, adding: “Around the world, seabirds are declining faster than any other bird group.”) Microplastics have been found in beer, honey, and sixteen of seventeen tested brands of commercial sea salt, across eight different countries. The more we test, the more we find; and while nobody yet knows the health impact on humans, in the oceans a plastic microbead is said to be one million times more toxic than the water around it. Chances are, if we started slicing open human cadavers to look for microplastics—as we are beginning to do with tau proteins, the supposed markers of CTE and Alzheimer’s—we’d be finding plastic in our own flesh, too. We can breathe in microplastics, even when indoors, where they’ve been detected suspended in the air, and do already drink them: they are found in the tap water of 94 percent of all tested American cities. And global plastic production is expected to triple by 2050, when there will be more plastic in the ocean than fish.

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Plastic panic has a strange relationship to climate change, in that it seems to draw on premonitions about the degradation of the planet while focusing on something that has very little to do with global warming. But it’s not only carbon emissions that are tied up in climate change. Other pollution is, too. One of the connections is relatively attenuated: plastics are produced by industrial activity that also produces pollutants, including carbon dioxide. A second is more direct but, in the scheme of things, trivial: when plastics degrade, they release methane and ethylene, another powerful greenhouse gas.

But a third relationship between non-carbon pollution and the temperature of the planet is far more horrifying. This is not the problem of plastic but of “aerosol pollution”—the blanket term for any particles suspended in our atmosphere. Aerosol particles actually suppress global temperature, mostly by reflecting sunlight back into outer space. In other words, all of the non-carbon pollution we’ve exhausted from our power plants and our factories and our automobiles—suffocating some of the largest and most prosperous cities of the world and consigning many millions of the lucky to hospital beds, and many millions of others to early deaths—all of that pollution has been, perversely, reducing the amount of global warming we are currently experiencing.

How much? Probably about half a degree—and possibly more. Already, aerosols have been reflecting so much sunlight away from the earth that, in the industrial era, the planet has only heated up two-thirds as much as it would have otherwise. If we had somehow managed to produce precisely the same volume of carbon emissions since the beginning of the Industrial Revolution as we have, while somehow keeping the skies clear of aerosol pollution, the temperature rise would be half again higher than it is now. The result is what the Nobel laureate Paul Crutzen has called a “Catch-22” and what the climate writer Eric Holthaus has described, perhaps more incisively, as a “devil’s bargain”: a choice between public-health-destroying pollution on the one hand, and, on the other, clear skies whose very clearness and healthiness will dramatically accelerate climate change. Eliminate that pollution and you save millions of lives each year, but also create a dramatic spike in warming. That would bring us to between 1.5 and 2 degrees warmer than the preindustrial baseline—pushing us right up to the threshold of 2 degrees of warming, long thought to be the border separating a livable future from climate catastrophe.

For almost a generation now, engineers and futurists have contemplated the practical implications of this phenomenon, and the prospect of suppressing global temperature with a program of suspended particles—that is, polluting the air on purpose to keep the planet cooler. Often grouped together under the umbrella term “geoengineering,” this prospect has been received by the public as a worst-case scenario, nearly science fiction—and has, in fact, informed much of the recent sci-fi that has addressed itself to the climate crisis. And yet it has gained a terrific amount of currency among the most concerned climate scientists, many of whom will also note that none of the quite modest goals of the Paris climate accords can be achieved without negative-emissions technologies—at present prohibitively expensive.

Carbon capture may indeed prove to be “magical thinking,” but the cruder technologies—we know these will work. Rather than sucking carbon out of the atmosphere, we could shoot pollution into the sky on purpose; perhaps the most plausible version involves sulfur dioxide. That would turn our sunsets very red, would bleach the sky, would make more acid rain.

It would also cause tens of thousands of additional premature deaths each year, through its effect on air quality. A 2018 paper suggested it would rapidly dry the Amazon, producing many more wildfires. The negative effect on plant growth would entirely cancel out the positive effect on global temperature, according to another 2018 paper; in other words, at least in terms of agricultural yield, solar geoengineering would offer no net benefit at all.

Once we began such a program, we could never stop. Even a brief interruption, a temporary dispersal of our red sulfur umbrella, could send the planet plunging several degrees of warming forward into a climate abyss. Which would make whatever installations were sustaining that umbrella quite vulnerable to political gamesmanship and terrorism, as its advocates themselves would acknowledge. And yet many scientists still describe geoengineering as an inevitability—it’s just so cheap, they say. Even an environmentalist billionaire, going rogue, could make it happen on their own.