By Elizabeth Kolbert
Like millions of other Americans, I first learned about climate change in the summer of 1988. For its day, it was a scorcher: Yellowstone National Park burst into flames; the Mississippi River ran so low that almost four thousand barges got backed up at Memphis; and, for the first time in its history, Harvard University shut down owing to heat. It was on an afternoon when the mercury in Washington, D.C., hit ninety-eight degrees that James Hansen, then the head of nasa’s Goddard Institute for Space Studies, told a Senate committee that “the greenhouse effect has been detected and is changing our climate now.” Speaking to reporters after the hearing, Hansen went a step further: “It is time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here.”
Hansen’s warning was certainly not the first. A report to President Lyndon Johnson in 1965 noted that the effect of burning fossil fuels was likely to be “deleterious from the point of view of human beings.” Another report, prepared for the Department of Energy in 1979, predicted that even a relatively small increase in temperature could lead to the ultimate “disintegration” of the West Antarctic ice sheet, a process that would raise global sea levels by sixteen feet. A third report, also from 1979, found that, as carbon accumulated in the atmosphere, there was no doubt that the climate would change and “no reason to believe” that the change “will be negligible.” But, for some reason, when Hansen spoke up, on that sweltering afternoon in June, the story of climate change shifted. The Times ran its article at the top of page 1, under a three-column headline: “global warming has begun, expert tells senate.” The following year, Bill McKibben published “The End of Nature,” first as a New Yorker piece under the rubric “Reflections,” and then, in longer form, as a book.
Had the words of either man been heeded in the intervening three decades, the world today would be a very different place—incalculably better off in innumerable ways. Instead, during that interval, some two hundred billion metric tons of carbon have been spewed into the atmosphere. (This is roughly as much CO2 as had been emitted from the start of the Industrial Revolution to that point.) Meanwhile, trillions of dollars have been sunk into coal-burning power plants, oil pipelines, gas pipelines, liquid-natural-gas export terminals, and a host of other fossil-fuel projects that, in a saner world, would never have been constructed. And global temperatures, as everyone can by now attest—though some still refuse to acknowledge—have continued to rise, to the point where the sweltering summer of 1988 no longer stands out as particularly hot. The nineteen-nineties were, on average, warmer than the eighties, the aughts hotter than the nineties, and the past decade hotter still. Each of the past five years has ranked among the warmest on record.
The New Yorker has run dozens of pieces on climate change. All might be described as “reflections” on this fundamental disconnect. Even as the consequences—rising seas, fiercer droughts, longer wildfire seasons, more devastating storms—have become daily news, global carbon emissions have continued to increase. In 2019, they reached a new record of ten billion metric tons. Emissions in India rose by almost two per cent, and in China by more than two per cent. In the United States, they actually dropped, by about 1.5 per cent. On November 4, 2019, the Trump Administration formally notified the United Nations that it planned to withdraw from the Paris climate accord, negotiated by the Obama Administration back in 2015. The very next day, a group called the Alliance of World Scientists released a statement, signed by eleven thousand researchers, warning that “the climate crisis has arrived and is accelerating faster than most scientists expected.”
“Especially worrisome,” the statement continued, were “irreversible climate tipping points,” the crossing of which “could lead to a catastrophic ‘hothouse Earth,’ well beyond the control of humans.”
What will the Earth look like thirty years from now? To a discomfiting extent, the future has already been written. There’s a great deal of inertia in the climate system; as a result, we’ve yet to experience the full effects of the CO2 that’s been emitted to date. No matter what happens during the next few decades, it’s pretty much guaranteed that glaciers and ice sheets will continue to melt, as temperatures and sea levels continue to rise.
But to an extent that, depending on your perspective, is either heartening or horrifying, the future—and not just of the next several decades but of the next several millennia—hinges on actions that will be taken by the time today’s toddlers reach adulthood. What’s technically referred to as “dangerous anthropogenic interference with the climate system” and colloquially known as “catastrophe” is warming so dramatic that it’s apt to obliterate whole nations (such as the Marshall Islands and the Maldives) and destroy entire ecosystems (such as coral reefs). A host of scientific studies suggest that a temperature increase of two degrees Celsius (3.6 degrees Fahrenheit) or more would qualify. A great many studies suggest that warming of 1.5 degrees Celsius (2.7 degrees Fahrenheit) would be enough to do the trick. At current emissions rates, the 1.5-degree threshold will be crossed in about a decade. As Drew Shindell, an atmospheric scientist at Duke University, told Science, “No longer can we say the window for action will close soon—we’re here now.”
So how hot—which is to say, how bad—will things get? One of the difficulties of making such predictions is that there are so many forms of uncertainty, from the geopolitical to the geophysical. (No one, for example, knows exactly where various “climate tipping points” lie.) That being said, I’ll offer three scenarios.
In one scenario—let’s call this “blue skies”—the world will finally decide to “stop waffling” and start to bring emissions down more or less immediately. In the U.S., proponents of the Green New Deal have proposed a “ten-year national mobilization” in order to meet a hundred per cent of the country’s power demand “through clean, renewable, and zero-emission energy sources.” Such a timetable is obviously fantastically ambitious, but not for this reason infeasible. According to a report by the International Energy Agency, using technologies now available, offshore wind turbines could provide the country with twice as much electricity as it currently uses, and, according to some estimates, weaning the U.S. off fossil fuels would create tens of millions of jobs.
