“Systems”
What I call cascades, climate scientists call “systems crises.” These crises are what the American military means when it names climate change a “threat multiplier.” The multiplication, when it falls short of conflict, produces migration—that is, climate refugees. Since 2008, by one count, it has already produced 22 million of them.
In the West, we often think of refugees as a failed-state problem—that is, a problem that the broken and impoverished parts of the world inflict on relatively more stable, and wealthier, societies. But Hurricane Harvey produced at least 60,000 climate migrants in Texas, and Hurricane Irma forced the evacuation of nearly 7 million. As with so much else, it will only get worse from here. By 2100, sea-level rise alone could displace 13 million Americans—a few percent of the country’s total population. Many of those sea-level refugees will come from the country’s southeast—chiefly Florida, where 2.5 million are expected to be flooded out of greater Miami; and Louisiana, where the New Orleans area is predicted to lose half a million.
As an unusually wealthy country, the United States is, for now, unusually suited to withstand such disruptions—one can almost imagine, over the course of a century, tens of millions of resettled Americans adapting to a ravaged coastline and a new geography for the country. Almost. But warming is not just a matter of sea level, and its horrors will not hit nations like the United States first. In fact, the impacts will be greatest in the world’s least developed, most impoverished, and therefore least resilient nations—almost literally a story of the world’s rich drowning the world’s poor with their waste. The first country to industrialize and produce greenhouse gas on a grand scale, the United Kingdom, is expected to suffer least from climate change. The world’s slowest-developing countries, producing the least emissions, will be among those hardest hit; the climate system of the Democratic Republic of Congo, one of the world’s poorest countries, is scheduled to be especially profoundly perturbed.
The Congo is mostly landlocked, and mountainous, but in the next generation of warming those features will not be protections. Wealth will be a buffer for some countries, but not a safeguard, as Australia is learning already: by far the richest of all the countries staring down the most intense, most immediate warming barrages, it is an early test case of how the world’s affluent societies will bend, or buckle, or rebuild under the pressure of temperature changes likely to hit the rest of the well-off world only later this century. The country was founded on genocidal indifference to the native landscape and those who inhabited it, and its modern ambitions have always been precarious: Australia is today a society of expansive abundance, jerry-rigged onto a very harsh and ecologically unforgiving land. In 2011, a single heat wave there produced significant tree dieback and coral bleaching, the death of plant life, crashes in local bird populations and dramatic spikes in the number of certain insects, and transformations of ecosystems both marine and terrestrial. When the country enacted a carbon tax, its emissions fell; when, under political pressure, the tax was repealed, they rose again. In 2018, the country’s parliament declared global warming a “current and existential national security risk.” A few months later, its climate-conscious prime minister was forced to resign, for the shame of attempting to honor the Paris accords.
The wheels of all communities are greased by abundance; baked by deprivation, they stall and crack. The paths are familiar ones, even to those who have only ever known affluence, their lives creamily frictionless but stimulated by entertainments tracing the arc of social decline: market breakdowns, price gouging, the hoarding of goods and services by the well-off and well-armed, the retreat of law enforcement into self-enrichment, and the disappearance of any expectation of justice making survival suddenly a matter of entrepreneurial skill.
More than 140 million people in just three regions of the world will be made climate migrants by 2050, the World Bank projected in a 2018 study, assuming current warming and emissions trends: 86 million in sub-Saharan Africa, 40 million in South Asia, and 17 million in Latin America. The most commonly cited estimate from the United Nations’ International Organization for Migration suggests numbers a bit higher—200 million, total, by 2050. These figures are quite high—higher than most non-advocates credit. But according to the U.N. IOM, climate change may unleash as many as a billion migrants on the world by 2050. One billion—that is about as many people as live today in North and South America combined. Imagine the two continents suddenly drowned in the sea, the whole New World submerged, and everyone left bobbing at the surface now fighting for a foothold, somewhere, anywhere, and, if someone else is scrambling for the same dry spot, scrambling to get there first.
The system in crisis is not always “society”; the system can also be the body. Historically, in the United States, more than two-thirds of outbreaks of waterborne disease—illnesses smuggled into humans through algae and bacteria that can produce gastrointestinal problems—were preceded by unusually intense rainfall, disrupting local water supplies. The concentration of salmonella in streams, for instance, increases significantly after heavy rainfall, and the country’s most dramatic outbreak of waterborne disease came in 1993, when more than 400,000 in Milwaukee fell ill from cryptosporidium immediately after a storm.
Sudden rainfall shocks—both deluges and their opposite, droughts—can devastate agricultural communities economically, but also produce what scientists call, with understatement, “nutritional deficiencies” in fetuses and infants; in Vietnam, those who passed through that crucible early on, and survived, were shown to start school later in life, do worse when they got there, and grow less tall than their peers. In India, the same cycle-of-poverty pattern holds. The lifelong impacts of chronic malnutrition are more troubling still for being permanent: diminishing cognitive ability, flattened adult wages, increased morbidity. In Ecuador, climate damage has been seen even in middle-class children, who bear the mark of rainfall shocks and extreme temperatures on their wages twenty to sixty years after the fact. The effects begin in the womb, and they are universal, with measurable declines in lifetime earnings for every day over ninety degrees during a baby’s nine months in utero. The impacts accumulate later in life, too. An enormous study in Taiwan found that, for every single unit of additional air pollution, the relative risk of Alzheimer’s doubled. Similar patterns have been observed from Ontario to Mexico City.
As conditions of environmental degradation become more universal, it may, perversely, require more imagination to consider their costs. When the deprived are no longer outlier communities but instead whole regions, whole countries, conditions that once may have seemed inhumane now appear, to a future generation who knows no better, simply “normal.” In the past, we have looked in horror at the stunted growth of national populations who passed through famines both natural (Sudan, Somalia) and man-made (Yemen, North Korea). In the future, climate change may stunt us all, in one way or another, with no control group entirely spared.
You might expect these premonitions to settle like sediments into family planning. And indeed, among the young and well-off in Europe and the United States, for whom reproductive choices are often freighted with political meaning, they have. Among this outwardly conscientious cohort, there is much worry about bringing new children into a degraded world, full of suffering, and about “contributing” to the problem by crowding the climate stage with more players, each a little consumption machine. “Want to fight climate change?” The Guardian asked in 2017. “Have fewer children.” That year and the next, the paper published several variations on the theme, as did many other publications delivered to the lifestyle class, including The New York Times: “Add this to the list of decisions affected by climate change: Should I have children?”
The effect on the personal decisions of the consumer class is perhaps a narrow way of thinking about global warming, though it demonstrates a strain of strange ascetic pride among the well-to-do. (“The egoism of child-bearing is like the egoism of colonizing a country,” the novelist Sheila Heti writes, in a representative passage from Motherhood, her meditation on the meaning of parenthood, which she chose to avoid.) But of course further degradation isn’t inescapable; it is optional. Each new baby arrives in a brand-new world, contemplating a whole horizon of possibilities. The perspective is not naive. We live in that world with them—helping make it for them, and with them, and for ourselves. The next decades are not yet determined. A new timer begins with every birth, measuring how much more damage will be done to the planet and the life this child will live on it. The horizons are just as open to us, however foreclosed and foreordained they may seem. But we close them off when we say anything about the future being inevitable. What may sound like stoic wisdom is often an alibi for indifference.
In a world of suffering, the self-interested mind craves compartmentalization, and one of the most interesting frontiers of emerging climate science traces the imprint left on our psychological well-being by the force of global warming, which can overwhelm whatever methods we devise to cope—that is, the mental health effects of a world on fire. Perhaps the most predictable vector is trauma: between a quarter and a half of all those exposed to extreme weather events will experience them as an ongoing negative shock to their mental health. In England, flooding was found to quadruple levels of psychological distress, even among those in an inundated community but not personally affected by the flooding. In the aftermath of Hurricane Katrina, 62 percent of evacuees exceeded the diagnostic threshold for acute stress disorder; in the region as a whole, nearly a third had PTSD. Wildfires, curiously, yielded a lower incidence—just 24 percent of evacuees in the aftermath of one series of California blazes. But a third of those who lived through fire were diagnosed, in its aftermath, with depression.
Even those watching the effects from the sidelines suffer from climate trauma. “I don’t know of a single scientist that’s not having an emotional reaction to what is being lost,” Camille Parmesan, who shared the 2007 Nobel Peace Prize with Al Gore, has said. Grist has called the phenomenon “climate depression,” Scientific American “environmental grief.” And while it may seem intuitive that those contemplating the end of the world find themselves despairing, especially when their calls of alarm have gone almost entirely unheeded, it is also a harrowing forecast of what is in store for the rest of the world, as the devastation of climate change slowly reveals itself. In the sense of psychological distress, which so many of them endure, climate scientists are the canaries in our coal mine. This may be why so many of them seem concerned with the risks of crying wolf about warming: they’ve learned enough about public apathy to worry themselves into knots about just when, and precisely how, to raise the alarm.
In certain places, that alarm has been raised for them. Those studying the phenomenon are only suffering secondhand—which is a sign of just how intense the firsthand impact has been. Unsurprisingly, climate trauma is especially harsh in the young—in this, our folk wisdom about the impressionable minds of children is reliable. Thirty-two weeks after Hurricane Andrew hit Florida in 1992, killing forty, more than half of children surveyed had moderate PTSD and more than a third had a severe form; in the high-impact areas, 70 percent of children scored in the moderate-to-severe range fully twenty-one months after the Category 5 storm. By dismal contrast, soldiers returning from war are estimated to suffer from PTSD at a rate between 11 and 31 percent.
One especially detailed study examined the mental health fallout from Hurricane Mitch, a Category 5 storm and the second-deadliest Atlantic hurricane on record, which struck Central America in 1998, leaving 11,000 dead. In Posoltega, the most hard-hit region of Nicaragua, children had a 27 percent chance of having been seriously injured, a 31 percent chance of having lost a family member, and a 63 percent chance of their home having been damaged or destroyed. You can imagine the aftereffects. Ninety percent of adolescents in the area were left with PTSD, with the average adolescent boy registering at the high end of the range of “severe” PTSD, and the average teenage girl registering over the threshold of “very severe.” Six months after the storm, four out of every five teenage survivors from Posoltega suffered from depression; more than half, the study found, compulsively nursed what the authors called, a bit euphemistically, “vengeful thoughts.”
And then there are the more surprising mental health costs. Climate affects both the onset and the severity of depression, The Lancet has found. Rising temperature and humidity are married, in the data, to emergency-room visits for mental health issues. When it’s hotter out, psychiatric hospitals see spikes in proper inpatient admissions, as well. Schizophrenics, especially, are admitted at much higher rates when the temperatures are higher, and, inside those hospitals, ward temperature significantly increases symptom severity in schizophrenic patients. Heat waves bring waves of other things, too: mood disorders, anxiety disorders, dementia.
Heat produces violence and conflict between people, we know, and so it should probably not surprise us that it also generates a spike in violence against oneself. Each increase of a single degree Celsius in monthly temperature is associated with almost a percentage point rise of the suicide rate in the United States, and more than two percentage points in Mexico; an unmitigated emissions scenario could produce 40,000 additional suicides in these countries by 2050. One startling paper by Tamma Carleton has suggested that global warming is already responsible for 59,000 suicides, many of them farmers, in India—where one-fifth of all the world’s suicides now occur, and where suicide rates have doubled since just 1980. When temperatures are already high, she found, a rise of just one additional degree, on a single day, will produce seventy additional corpses, each dead by the farmer’s own hand.
If you have made it this far, you are a brave reader. Any one of these twelve chapters contains, by rights, enough horror to induce a panic attack in even the most optimistic of those considering it. But you are not merely considering it; you are about to embark on living it. In many cases, in many places, we already are.
In fact, what is perhaps most remarkable about all of the research summarized to this point—concerning not only refugees, health, and mental health, but also conflict and food supply and sea level and all of the other elements of climate disarray—is that it is research emerging from the world we know today. That is, a world just one degree warmer; a world not yet deformed and defaced beyond recognition; a world bound largely by conventions devised in an age of climate stability, now barreling headlong into an age of something more like climate chaos, a world we are only beginning to perceive.
Some climate research is speculative, of course, projecting our best insights into physical processes and human dynamics onto planetary conditions no human being of any age or era has ever experienced. Some of these predictions will surely be falsified; that is how science proceeds. But all of our science arises from precedent, and the next era for climate change has none. The twelve elements of climate chaos are, as Donald Rumsfeld once put it in his incongruously useful phrasing, the “known knowns.” This is the least concerning category; there are two more.
These sketches may feel exhaustive, at times even overwhelming. But they are merely sketches, to be filled in and fleshed out over the coming decades—if the previous decades are any guide, more often by bleaker science than by reassuring findings. For all our earned confidence in our knowledge of global warming—that it is real, that it is anthropogenic, that it is driving sea-level rise and Arctic melt and the rest—we still know only so much. Twenty years ago, there was no meaningful research on the relationship between climate change and economic growth; ten years ago, not much about climate and conflict. Fifty years ago, there was hardly any research about climate change whatsoever.
The pace of that scholarship is exhilarating, but it also counsels humility; there remains so much we do not know about the way global warming affects the way we live today. Now picture how much we’ll know fifty years from now—and how much more gruesome our self-immolation will likely seem, even if we avoid its worst outcomes. Will warming trigger rapid feedback loops powered by the release of Arctic methane, or by the dramatic slowdown of the ocean’s circulation system? It’s impossible to say for sure. Will we protect ourselves by dispersing sulfur into our own now-red atmosphere, subjecting the entire planet to the uncertain health effects of those particles, or by erecting carbon-sucking plantations the size of continents? It’s difficult to predict. These, then, are among the “known unknowns.” And that oracle Rumsfeld furnished us with one conceptual category scarier still.
Which all means that these twelve threats described in these twelve chapters yield a portrait of the future only as best as it can be painted in the present. What actually lies ahead may prove even grimmer, though the reverse, of course, is also possible. The map of our new world will be drawn in part by natural processes that remain mysterious, but more definitively by human hands. At what point will the climate crisis grow undeniable, un-compartmentalizable? How much damage will have already been selfishly done? How quickly will we act to save ourselves and preserve as much of the way of life we know today as possible? For the sake of clarity, I’ve treated each of the threats from climate change—sea-level rise, food scarcity, economic stagnation—as discrete threats, which they are not. Some may prove offsetting, some mutually reinforcing, and others merely adjacent. But together they form a latticework of climate crisis, beneath which at least some humans, and probably many billions, will live. How?