Climate Realism Is a Delusion
By shooting for 3 degrees Celsius of warming, the world could slide toward a more cataclysmic 4 degrees.
This year’s Conference of the Parties, the annual United Nations meeting meant to avert catastrophic climate change, was subject to a ham-fisted metaphor. On Thursday, the Brazilian venue hosting the conference burst into flames from what was likely an electrical fire. In its 30 years, COP has frequently been a ritual in frustration and futility, ending with a set of pledges and promises that have rarely gone as far as scientists say they need to, followed by weeks of postmortem finger-pointing and self-flagellation. And yesterday, once again delegates landed on a heavily compromised text that does little to materially steer the planet off fossil fuels.Many of the fingers pointed toward an empty chair and the absence of the largest oil-and-gas producer on planet Earth (the United States). Meanwhile, delegates from drowning, subsistence-farming volcanic archipelagos in the South Pacific humbly pleaded with countries such as Saudi Arabia and Russia to pledge to someday stop pumping their oceans of oil, the most profitable commodity in the world. It didn’t work.“We know some of you had greater ambitions for some of the issues at hand,” COP30 President André Corrêa do Lago sheepishly told the assembly.Every year, environmental NGOs, climate scientists, concerned citizens, and government ministers alike register confusion and despair over the fact that after so many cycles of these meetings, industrial civilization erupts more carbon dioxide into the atmosphere than ever before. This year, it reached a staggering new peak with 38.1 gigatons of the stuff—two orders of magnitude more than is put out by all of the volcanoes on Earth combined each year, and a pace that is virtually unprecedented in all of geological history.Even if all other emissions from fossil fuels halted tomorrow, CO2 emissions from the global food system alone could eventually push us past 2 degrees Celsius in warming, half a degree higher than the always-aspirational 1.5 degrees Celsius goal set forth in the 2016 Paris Agreement. At this point, reaching that goal would require an impossible slashing of global emissions by a quarter every year for the next four years until they reach zero. As things stand, the UN projects that current policies will result in almost 3 degrees Celsius of warming by 2100. Unfortunately, that 1.5-degree benchmark wasn’t selected at random. As one landmark paper puts it, the “Earth may have left a safe climate state beyond 1°C global warming,” and even 1.5 degrees would possibly invite inexorable ice-sheet collapse, coral-reef die-off, and permafrost thaw. All of this grim news has given way to a new kind of cynical resignation to this future, and a vision in which the world scales back its climate ambitions and accepts an all but permanent and prominent role for fossil fuels in the global economy. This forfeit, recently championed by Bill Gates, flies under the banner of “climate realism” or, more sunnily, “climate pragmatism.” In this view, the trade-offs between minimizing global warming and pursuing other goals for humanity are too steep, and the consequences of somewhat-checked warming will be manageable. If climate negotiators were naive about the political economy of the energy transition when COP started 30 years ago, though, then the purveyors of this kind of “pragmatism” are downright oblivious to the implications of a 3 degrees–warmer world that they’ve made conceptual peace with.If warming the planet beyond 1 degree Celsius isn’t safe, then 3 degrees is madness. Forget coral reefs: This collapse would cascade into the broader ocean as the sea succumbs to merciless heat waves, oxygen loss, and acidification, and entire ecosystems—seagrass beds, kelp forests, mangroves—fall away. On land, this vanishing act might extend to the Amazon rainforest, which—already relentlessly pared back by deforestation—could submit to a runaway drying. In the human world, migration could be measured in billions of people, as familiar rains that water staple crops depart for distant latitudes and unprecedented heat waves in eastern China and the Indus River Valley surpass the limits of human physiology. Even the U.S. Midwest would begin to see deadly hot and humid conditions, today experienced only in extraordinarily rare heatwaves in places such as the Persian Gulf and inland Pakistan.“In the United States, just 3 degrees Celsius of warming conditions in simulations tend to be hotter—when humidity is factored in—than heat waves in North Africa today,” the Purdue climate scientist Matthew Huber wrote in the Bulletin of the Atomic Scientists. “These heat waves of the future could devastate US livestock yields, if they don’t kill the animals outright.” Humans, being animals, would also be killed by the heat. One recent study showed that in a 3 degree–warmer world, deaths resulting from a week-long exceptional heat wave, like the one that struck Europe in 2003, would rival peak-COVID mortality rates, killing 32,000 people in Europe.This would be only one in a cascade of problems facing humanity. By 2030, the global demand for fresh water is expected to outstrip supplies by 40 percent, and the shortage would be made more dire in the following decades when mountain glaciers that supply drinking water to more than 2 billion people begin to vanish at the same time that underground aquifers fail to recharge. (The recurrent droughts would push farmers to draw those aquifers down faster.) Meanwhile, as flooding and hurricanes ravage the coasts, and wildfires, flooding, and severe storms strike inland, insurance markets may all but collapse—even in supposed climate refuges such as Minnesota. Erratic weather and volatile yields will drive food prices persistently higher, and communities—whether at the municipality scale or entire countries—may go bankrupt while trying to patch up battered and strained infrastructure amid higher borrowing costs and closed lines of credit. The entire financial system, including government bonds and mortgages, is premised on the idea that tomorrow will look something like today. In a world that’s 3 degrees warmer, it assuredly will not.That is, if 3 degrees warmer is indeed where we’re headed. Although many climate stories quote temperature estimates for the year 2100 down to the tenth of a degree, this betrays an unrealistic level of precision in climate forecasts. Not only is there uncertainty in our predictions about just what level of carbon emissions a specific policy might ultimately lead to, there are also uncertainties in our estimates of the climate’s sensitivity to greenhouse gases—and potentially even more worrying uncertainties about how the Earth’s carbon cycle will respond to higher CO2 and warming. The carbon cycle involves the exceedingly complex and restless planetary give-and-take of carbon as it moves among the crust, oceans, and atmosphere, and through life itself. It could be that carbon-loaded reservoirs, such as soils and permafrost, will exhale more carbon dioxide and methane back into the atmosphere than we expect in response to warming. The uncertainty around this potentially menacing feedback only becomes greater, and more worrying, the harder we push on the Earth system. The carbon sinks that have been mopping up our mess may not comply with our continued gavage of CO2, either, as forests burst into flames and the upper ocean has its fill.All of this means that, by shooting for a limit of 3 degrees Celsius, we very well may end up warming the planet by 4 degrees instead. Indeed, the same widely quoted recent UN estimate that predicts warming of 2.8 degrees Celsius under current policies also has an uncertainty range up to a perhaps unlikely but truly unthinkable 4.6 degrees Celsius. There is “no certainty that adaptation to a 4°C world is possible,” as even the starchy World Bank has warned. “The projected 4°C warming simply must not be allowed to occur.” Humanity might not roll snake eyes with the climate in this way—2.8 degrees in theory could end up meaning 2.8 degrees in practice. Still, this is an actuarial risk you wouldn’t take with a new house, much less with the only known habitable planet in the universe.COP itself has become an annual punching bag and synecdoche for climate inaction more broadly. But, obviously, we need an international body to convene and coordinate around such a dire planetary challenge. The problem is that far more powerful forces are driving global industrial civilization than can be meaningfully countervailed by a yearly meeting of bureaucrats at the UN. Today, as was the case 30 years ago, more than 80 percent of industrial civilization is powered by fossil fuels. As a species, we now have to switch treadmills going 100 mph, to a new global industrial metabolism based on sunlight, wind, water, the heat of the Earth, and the atom itself.Slowing this metabolic planetary transformation are the provincial, self-interested, and mutually incompatible demands from society, in a world carved up by economic inequality, varying vulnerabilities to future climate change, and the uneven accidents of geologic endowment. At COP30, the titans of fossil-fuel production and consumption that did bother to show up—China, India, Saudi Arabia, and Russia—still opposed a roadmap to get off fossil fuels, which was struck from the final text. And, unless compensated by the developed world, economically poor but oil-rich countries are unlikely to forgo selling the most profitable commodity in the world. Replacing fossil energy with renewables will require a level of mining that might be somewhat smaller than the footprint for fossil fuels but that many in the climate world are frankly in denial about. Tasks such as updating the U.S. grid at the scale needed for decarbonization would likely cost more than building the entire interstate highway system did, even when adjusted for inflation.At this point, it’s a clichéd refrain among more pessimistic climate commentators that humanity has never managed an energy transition before, only energy additions. (To wit, people still burn about as much wood as they ever have.) China, the world’s biggest emitter, has embarked on a mindboggling project of decarbonization, producing three-quarters of the world’s solar panels and wind turbines—but it still evaporates 1,500 Great Pyramids of Giza’s worth of coal into the atmosphere each year, four times more than the United States did at its peak.Everything you’ve read above, the relentlessly dour litany of climate threats and the meditation on the intransigence of climate politics, has also been spun—by commentators availed of the same set of facts—as a success story. China’s emissions may soon peak, or perhaps already have. And it is true that our estimates of future warming have come down, even in the past decade, from truly apocalyptic forecasts to merely disastrous levels of warming, but still outside the range experienced in the evolutionary history of Homo sapiens. For that we owe meetings such as COP no small debt of gratitude.The Earth, of course, is indifferent to what’s politically possible, and where it’s headed is still dangerous for humanity. The planet has seen entire living worlds wiped away by warming many times before, and there’s no reason to think it’s sentimental about organized industrial society. Getting emissions to near zero will be incredibly, maddeningly difficult. It will be ugly. There will be losers. Ultimately, though, there will be many more winners. Until that day, it remains the case that we are embarking on—in fact, accelerating—the biggest chemistry experiment on the planet in 66 million years, and one of the fastest derangements of the carbon cycle in the age of animal life.
