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.
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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?
III
The Climate Kaleidoscope
Storytelling
It should be no great prize to be right about the end of the world. But humans have told those stories incessantly, across millennia, the lessons shifting with each imagined Armageddon. You’d think that a culture woven through with intimations of apocalypse would know how to receive news of environmental alarm. But instead we have responded to scientists channeling the planet’s cries for mercy as though they were simply crying wolf. Today, the movies may be millenarian, but when it comes to contemplating real-world warming dangers, we suffer from an incredible failure of imagination. This is climate’s kaleidoscope: we can be mesmerized by the threat directly in front of us without ever perceiving it clearly.
On-screen, climate devastation is everywhere you look, and yet nowhere in focus, as though we are displacing our anxieties about global warming by restaging them in theaters of our own design and control—perhaps out of hope that the end of days remains “fantasy.” Game of Thrones opens with an unmistakable climate prophecy, but warns “winter is coming”; the premise of Interstellar is an environmental scourge, but the scourge is a crop blight. Children of Men depicts civilization in semi-collapse, but collapsed by a fertility menace. Mad Max: Fury Road unfurls like a global-warming panorama, a scrolling saga of a world made desert, but its political crisis comes, in fact, from an oil shortage. The protagonist of The Last Man on Earth is made that way by a sweeping virus, the family of A Quiet Place is hushed by giant insect predators lurking in the wilderness, and the central cataclysm of the “Apocalypse” season of American Horror Story is a throwback—a nuclear winter. In the many zombie apocalypses of this era of ecological anxiety, the zombies are invariably rendered as an alien force, not an endemic one. That is, not as us.