This week, scientists reported that the collapse of a critical Atlantic current system is more likely than many of them feared. The Atlantic meridional overturning circulation, or Amoc, sends warm water from the Southern Ocean near Antarctica up to the Arctic Sea and then returns the cooled water back again. It’s responsible for shaping the weather patterns that much of society has been structured around, like the tropical rainfall belt and Northern Europe’s relatively mild winters. Amoc was already believed to be weakening as a result of warming oceans, increasing rainfall, and melting sea ice. Yet while projections of a more significant slowdown have ranged wildly, new research, incorporating real-world observations, suggests that it will slow by an estimated 42 to 58 percent by 2100. By the middle of this century, the Amoc slowdown could pass a point of no return, whereby its collapse becomes virtually inevitable.
It’s hard to overstate the seriousness of this finding. “This is an important and very concerning result,” Stefan Rahmstorf, of the Potsdam Institute for Climate Impact Research, told The Guardian. “It shows that the ‘pessimistic’ models, which show a strong weakening of the Amoc by 2100, are, unfortunately, the realistic ones.”
These pessimistic models could entail dire consequences: brutal, frigid winters in Northern Europe; disrupted growing seasons in South America; drought across the Sahel; and rapid sea level rise and stronger hurricanes along the Atlantic Coast of the United States. A shutdown could further decimate the ocean’s ability to absorb carbon dioxide, leading to an additional 0.2 degrees Celsius of global warming.
There is still debate within the scientific community as to the extent and speed of the Amoc slowdown and what exactly it will mean, but the historical evidence is sobering. When Amoc inexplicably weakened by 30 percent in 2009 and 2010, the Northeast U.S. saw seas rise at unprecedented rates. A study released last year showed that 50 percent of the doubling of flood risk there since 2005 can be attributed to Amoc’s slowdown to date. The last time the current collapsed—beginning about 12,800 years ago—Europe may have experienced Arctic-like conditions as average temperatures dropped by nearly 60 degrees Celsius within a matter of decades.
The new study comes as climate change has largely fallen out of political debates across much of the West. In response to the more than a month-long closure of the Strait of Hormuz, liberal and right-wing governments alike doubled down on coal, oil, and gas in the name of energy security. The mood in the U.S. might best be described as climate nihilism: Climate-denying Republicans are gutting climate rules and doing everything in their power to punish renewables and expand fossil fuel production; Democrats who championed their climate bona fides just a few years ago are quietly rolling back both laws and rhetoric about reducing emissions.
It is easier, psychologically, to imagine that all those people who were yelling about climate change a few years ago were shrill blue-haired radicals, loony NGOs, and politicians who were so eager to capture those groups’ votes and endorsements that they foolishly took up catastrophically unpopular positions on the issue. It is also easier to debate the right way to talk about the climate crisis politically than it is to reckon with the actual problem at hand. Arguably a major reason why climate change has dropped out of the national conversation is because it is such an incredibly upsetting thing to think about.
Liberal-coded rhetoric about “solving” climate change—almost always connected to a handful of exciting green technologies—can seem like its own, more well-intentioned form of denial. There is no solving climate change. It is already happening, and it will continue to get much, much worse even if the world were to magically end all fossil fuel combustion tomorrow. A world-historic proliferation of solar, geothermal, wind, and nuclear power will not on its own eliminate fossil fuel combustion, much less create viable fossil-free alternatives for cornerstones of modernity like concrete, steel, and nitrogen-based fertilizers. A thriving green tech sector also won’t figure out how to peaceably relocate the many millions of people living in places that are becoming uninhabitable.
To adequately plan for an inevitably climate-changed future—for mitigation, adaptation, and loss—the world’s governments would need to unite behind a war-like mobilization that would make even the most audacious of Soviet planners blush. In a war, however, at least by conventional metrics, one side can usually be said to have won once it’s over. Victory in a war on climate change, by contrast, would involve something like permanent battle, where the primary goal is to limit the numbers of losers to (optimistically) tens of millions rather than billions. The result would be a world that looks fundamentally different from our own. Given the quantity of greenhouse gasses that have already been deposited into the atmosphere, an enormous transformation in the ways people live now will happen—is happening—either way. The question isn’t whether we can preserve the world as it is and stop climate change, but whether we can plan for those changes to be as minimally destructive as possible.
This isn’t exactly a winning message. Neither, for that matter, will talking about the Amoc collapse win over swing voters in the United States. But the alternatives to engaging with reality are to lie about what’s happening or pretend that it isn’t happening. Those of us who aren’t running for office, at least, don’t have to be deniers.
