Even when it comes to war, historical memory has a sadistically short half-life, horrors and their causes gauzily evanescing into familiar folklore in less than the span of a single generation. But most wars throughout history, it is important to remember, have been conflicts over resources, often ignited by resource scarcity, which is what an earth densely populated and denuded by climate change will yield. Those wars don’t tend to increase those resources; most of the time, they incinerate them.
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The folklore of state conflict casts a long shadow—the patchwork quilt of nations tugged apart into a ghastly, mutually damaging disarray. Climate tugs at the individual threads of conflict, too: personal irritability, interpersonal conflict, domestic violence.
Heat frays everything. It increases violent crime rates, swearing on social media, and the likelihood that a major-league pitcher, coming to the mound after his teammate has been hit by a pitch, will hit an opposing batter in retaliation. The hotter it gets, the longer drivers will honk their horns in frustration; and even in simulations, police officers are more likely to fire on intruders when the exercises are conducted in hotter weather. By 2099, one speculative paper tabulated, climate change in the United States would bring about an additional 22,000 murders, 180,000 rapes, 3.5 million assaults, and 3.76 million robberies, burglaries, and acts of larceny. The statistics of the past are more inarguable, and even the arrival of air-conditioning in the developed world in the middle of the last century did little to solve the problem of the summer crime wave.
It’s not just temperature effects. In 2018, a team of researchers examining an enormous data set of more than 9,000 American cities found that air pollution levels positively predicted incidents of every single crime category they looked at—from car theft and burglary and larceny up to assault, rape, and murder. And then there are the ways that climate impacts can cascade into violence more circuitously. Between 2008 and 2010, Guatemala was hit by Tropical Storm Arthur, Hurricane Dolly, Tropical Storm Agatha, and Tropical Storm Hermine—this a country that was already one of the ten most affected by extreme weather and reeling in the same years from the eruption of a local volcano and a regional earthquake. All told, almost three million were left “food insecure,” and at least 400,000 needed humanitarian assistance; from the 2010 disasters alone, the country sustained damages totaling more than a billion dollars, or roughly a quarter of the national budget, devastating its roads and supply chains. In 2011, it was hit by Tropical Storm 12E, and, in the wake of the disasters, farmers turned to growing poppies; organized crime, already an enormous problem, exploded—which should perhaps not surprise us, given that recent research has shown that the Sicilian mafia was produced by drought. Today, Guatemala has the fifth-highest homicide rate in the world; according to UNICEF, it is the second most dangerous country in the world for children. Historically, the country’s cash crops have been coffee and sugarcane; in the coming decades, climate change could make both of them ungrowable.
“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.