Zero Hour: There’s No Stopping Climate Change, But How Bad It Gets Is Still Up To Us

When people you love are sick and dying, it’s hard to think about anything else. In the course of just a few short weeks, the coronavirus has upended our daily lives, causing immense suffering and economic chaos around the world. It’s hard to recall (or care, even) that it was 69 degrees Fahrenheit in Antarctica a few weeks ago — T-shirt weather in the coldest, most remote place on Earth. Or that bush fires burned 46 million acres in Australia, and by one count, a billion animals were lost. Or that there was a marine heat wave in the Pacific and devastating floods in Indonesia. But when this terrible pandemic ends, as it surely will, we will be faced once again with a central fact of 21st-century life: The longer we wait to get off fossil fuels, the hotter the world will get, and the faster climate chaos will accelerate.

This is not about saving the planet. For one thing, the planet itself is not at risk — in its 4.5-billion-year history, the Earth has been through much worse than anything we can throw at it. It’s civilization as we know it today that’s in trouble. Second, the whole notion of “saving” anything is a flawed way to think about the crisis we are facing. Yes, it is more important than ever that we eliminate fossil fuels and reduce suffering and loss in a warming world. And, yes, the faster we get off fossil fuels, the better chance we have to make sure we don’t push the climate system past irreversible tipping points, such as the collapse of the West Antarctic Ice Sheet, which could raise global sea levels by 10 feet.

But no matter how fast we act, we are not going to “fix” the climate like a doctor fixes a broken leg. “The Earth’s climate is not a binary system or a switch that you can toggle on and off,” says Kate Marvel, a climate scientist at NASA’s Goddard Institute for Space Studies in New York. Even if we stopped burning fossil fuels tomorrow and stabilized the Earth’s temperature where it is today, we would still face several feet of sea-level rise in the coming century, as well as collapsing coral reefs and changing rainfall patterns. “The notion that we can avoid climate change is unequivocally false,” says Marvel. “We’re at 1 degree of warming now, and we’re already seeing the impacts of climate change very clearly with wildfires, flooding, and other extreme weather events. But it’s also true that our actions over the next decade very much matter.”

We have already crossed one of the most important thresholds of the climate crisis: We’ve gone from “Is it happening?” to “What are we going to do about it?” In this new world, there are no solutions — only better and worse choices about where we will live, how we will live, who and what will survive, and who and what will be lost. Above all, it’s a world that will be defined by how hard we are willing to fight for our future.

“We might be living in a horror movie right now, but we are the ones writing the script,” says writer Mary Annaïse Heglar. “And we’re the ones who will decide how this movie will end.”

From the earliest days of the climate crisis, scientists have struggled to define the risks of life on a warming planet. “We have understood the basic physics of climate change for more than 120 years,” says Andrew Dessler, a climate scientist at Texas A&M. But nobody was too worried at first. The warming of the planet, if it was seen as a threat at all, was viewed as a far-off, distant event, something that would play out over century-long time scales.

The warming is a result of the slow accumulation of carbon dioxide in the atmosphere, which traps heat just like the glass roof of a greenhouse. Unlike other air pollutants, such as the chemicals that cause smog, which vanish as soon as you stop emitting them, a good fraction of CO2 that was emitted while factories forged cannons during the Civil War is still in the atmosphere today, and will remain for centuries into the future. “The climatic impacts of releasing CO2 will last longer than Stonehenge,” wrote climate scientist David Archer. “Longer than time capsules, longer than nuclear waste, far longer than the age of human civilization so far.” The fingerprints of accumulating CO2 in the atmosphere were also hard to detect, at least in real time. In March 1958, when scientist Charles Keeling first started measuring it from the Mauna Loa observatory in Hawaii, the CO2 level in the atmosphere was 315.71 parts per million. A year later, it was 316.71 parts per million. Why would anyone be alarmed by an increase of one part per million of CO2?

But in the atmosphere, small changes over time can add up to big impacts. In 1988, NASA scientist James Hansen testified before the U.S. Senate that the burning of fossil fuels was now altering the Earth’s climate. “Global warming has reached a level such that we can ascribe with a high degree of confidence a cause-and-effect relationship between the greenhouse effect and observed warming,” Hansen said. “It is already happening now.’’ He and other scientists understood the implications of this warming — droughts, heat waves, sea-level rise. But they didn’t have a clear timeline for when these impacts would occur or how severe they would be.

A map showing the average temperature rise over the past four years; 2016 and 2019 were the hottest on record. Credit: NASA’s Goddard Space Flight Center NASA's Goddard Space Flight Center

Big Oil and Big Coal understood the implications of rising CO2 levels all too well. They immediately began cranking out propaganda arguing that a warmer world was a better world. Groups like the Greening Earth Society argued that more CO2 meant plants would grow faster, agriculture would boom, and we would all enjoy more days at the beach. Companies like Exxon (now ExxonMobil) began spending hundreds of millions of dollars in a well-orchestrated campaign to deny, confuse, and block any understanding of the risks of burning fossil fuels. In the coming years, they organized and funded industry groups with innocuous-sounding names like the Global Climate Coalition, and poured money into conservative think tanks like the Competitive Enterprise Institute and the Heritage Foundation, where undermining climate science was job one.

In addition, there was a collective-action problem. Even if half the nations of the world decided to slash carbon pollution, if big fossil-fuel burners like the U.S. and China didn’t take action too, the problem wouldn’t be solved. Many leaders saw restrictions on carbon as hobbling their economy and thus jeopardizing their political power. As Dan Dudek, a vice president at the Environmental Defense Fund, puts it, “What president or prime minister is going to restrict fossil fuels if it means he or she will be turned out of office?”

But the biggest issue was simply defining the threat of global warming. With nuclear weapons, the risks were clear: Start a war, and millions of people could die in minutes. The ozone hole was similarly clear-cut: If you let deadly levels of radiation hit the Earth, you get cancer and die. In both cases, global treaties were effective in reducing risk. But with global warming, the threat was not so clear. Nobody was going to die — at least, not directly — from a few more parts per million of CO2 in the atmosphere.

In 1988, under the auspices of the U.N., the Intergovernmental Panel on Climate Change (IPCC) was created — an organization of top scientists tasked with issuing periodic reports that assessed the latest knowledge about climate change. The first report, released in 1990, was a weak sketch of the risks, from sea-level rise to drought to increased storm intensity. But it inspired the Earth Summit in Rio de Janeiro in 1992, where the issue of climate risk was addressed directly for the first time. The summit was a big event, with virtually every nation in the world signing a global treaty called the United Nations Framework Convention on Climate Change (UNFCCC). The goal of the treaty was “to stabilize greenhouse-gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic [human-caused] interference with the climate system.” Nice thought, but as Penn State climate scientist Michael Mann later wrote, “Dangerous to whom?” The risks to an islander living on a low atoll in the Pacific were surely different than the risks to the Mercedes-riding diplomats who crafted the treaty, to say nothing of the outsize risks to future generations.

In 1995, the IPCC followed up with a second report, which was more thorough but still full of cautious, bureaucratic language (“potentially serious changes have been identified”). Nobody but hardcore scientists and activists read it. In 1997, at the climate talks in Kyoto, Japan, UNFCCC members agreed to the Kyoto Protocol, which required that by 2012 developing countries cut total emissions of greenhouse gases by five percent from 1990 levels. The agreement got a lot of press and inspired high-minded speeches about the importance of reducing the level of CO2 in the Earth’s atmosphere. But it didn’t inspire much action. “Part of the problem was that negotiations focused on agreeing on the percentage of tons of carbon-dioxide-emission reductions, which no regular human being has any clue about,” Dudek explains. “How can you build political support around a goal that most people can’t understand, even if they wanted to?”

The Jakobshavn glacier, on the west coast of Greenland, is the fastest-moving glacier in the world. It is flowing into the sea at a rate of about 150 feet per day. If you fly along the face of it in a helicopter, as I did a few years ago, you can watch slabs of blue ice fall into the sea every few minutes. They eventually melt into the North Atlantic, adding almost imperceptibly to the level of water in the ocean, which pushes waves a fraction of an inch higher on beaches around the world — the climate crisis in action.

In the 1990s, Greenland also changed how scientists think about climate change. Until then, most climate scientists believed the Earth’s climate was a fairly steady system — that it might grow warmer or colder, but that changes were gradual, like water heating up in a pot. Wallace Broecker, a brash and colorful geochemist at Columbia University, who died in 2019, hypothesized that changes in the Gulf Stream system about 14,000 years ago, during a period known as the Younger Dryas, had caused dramatic temperature swings in the Northern Hemisphere. Evidence for this was sketchy until the mid-Nineties, when a team of researchers, including Richard Alley, a paleoclimatologist at Penn State, extracted a two-mile ice core from the Greenland ice sheet. By examining the decay of carbon isotope ratios in air bubbles trapped in the ancient ice, Alley found that at the end of the Younger Dryas, the temperature in Greenland warmed by 15 F in less than a decade. It was a remarkable discovery, which demonstrated that the Earth’s climate tended to lurch from one steady state to another. “You might think of the climate as a drunk,” Alley later explained. “When left alone, it sits. When forced to move, it staggers.”

Alley’s work revolutionized how scientists conceptualized changes that are to come. It also pushed scientists to think about climate risk in terms of temperature changes, not carbon-emission rates. In 2001, the IPCC issued its third report, which was far more pointed and urgent than previous reports. It’s remembered today mostly for a single graphic, known as “the burning embers” diagram. It was a simple chart with five bars that corresponded to five categories of climate risk, from “Risks of Extreme Weather Events” to “Risks of Large Scale Discontinuities” (such as the rapid melting of the Greenland and West Antarctic ice sheets). The bars were shaded from white to yellow to orange to dark red, depending on the severity of the risk, which were calculated on a scale from zero to 5 C of warming. “The diagram was revolutionary,” says Mann. “For the first time, the risks of climate change were intelligible to someone who didn’t have a degree in physics.”

In 2010, the UNFCCC threw out the old metric of measuring progress by emissions reductions. Instead, they adopted a goal of stabilizing warming at less than 2 C (3.6 F), which quickly became known as the threshold for dangerous climate change. Where did the 2 C target come from? Think of it as a rough balance between what should be done and what can be done. (“I would avoid thinking about these temperature targets as ever being based in science,” says Dessler.) Although a temperature target was much more coherent to most people than a percentage of emissions reductions, it reinforced an artificial notion that climate change was binary: Below 2 C of warming, all was good. Above 2 C, all hell breaks loose. “That is not how the climate system works,” says Dessler. “Is 1.8 C of warming better than 2 C? Yes. Is 2 C better than 2.5 C? Yes. But there is no bright line here.”

Mann’s question, “Dangerous to whom?” continued to haunt negotiations over climate targets. The better that scientists understood the climate system, the clearer it became that even a warming of 2 C put people in low-lying nations like Bangladesh at risk for increased flooding from rising seas, as well as other climate impacts. Was the 2 C target too high? Was it safe only for the privileged? The counterargument, however, was that a climate target needed to be achievable or nobody would take it seriously. Virtually every study showed that hitting the 2 C target would require a Herculean effort by all the industrialized nations of the world.

At the climate talks in Paris in 2015, even the 2 C target was seen as not strong enough. By then, the impacts of climate change were moving out of the modeling world and happening in real time. Greenland and Antarctica are shrinking “100 years ahead of schedule,” Alley said. Leaders of small island states like Tuvalu and the Maldives argued that the 2 C target was essentially dooming their nations. They pushed for an “aspirational goal” of limiting warming to 1.5 C (2.7 F), which eventually became embedded in the language of the Paris Agreement. Thus, 1.5 C became the new de facto threshold for dangerous climate change. But it was clear that the 1.5 C target was more of a desperate dream than a practical reality. As one observer in Paris quipped to me, “They may as well agree that all fairies shall ride unicorns too.”

There may be a climate scientist or energy analyst somewhere in the world who believes that limiting warming to 1.5 C is doable, but I haven’t met him or her. Net emissions would need to fall by half by 2030, and to zero by 2050. “The level of action and coordination necessary to limit global warming to 1.5 C utterly dwarfs anything that has ever happened on any other large-scale problem that humanity has ever faced,” journalist David Roberts wrote on Vox. “The only analogy that has ever come close to capturing what’s necessary is ‘wartime mobilization,’ but it requires imagining the kind of mobilization that the U.S. achieved for less than a decade during WWII happening in every large economy at once, and sustaining itself for the remainder of the century.”

If we blow past the 1.5 C target, as seems likely, where are we headed? Until recently, the IPCC had projected a warming of about 4.5 C by the end of the century if we continue on our current emissions path. That is truly a horrific number, one that would render large swaths of the Earth uninhabitable. But a recent study by Zeke Hausfather of the Breakthrough Institute in California and Justin Richie of the University of British Columbia demonstrated that this estimate was based on unreal projections of coal consumption and other factors. After they reanalyzed the data, they concluded the business-as-usual scenario may be something more like 3 C. Which would still be hellish, but less hellish than 4.5 C.

Even if we achieve the target of holding to 2 C, there will be unfathomable changes to our climate. In 2018, the IPCC published a special report that laid out the differences between a 2 C world and a 1.5 C world. “I was grumpy about the idea of the 1.5 report,” says NASA’s Kate Marvel. “I thought it was just fan fiction. But it had an unexpectedly galvanizing impact on people.” The report showed that, at 2 C, severe heat events would become 2.6 times worse, plant- and vertebrate-species loss two times worse, insect-species loss three times worse, and decline in marine fisheries two times worse. Instead of 70 percent of coral reefs dying, 99 percent will die. Many vulnerable and low-lying regions would become uninhabitable and the flow of refugees would rise dramatically.

Beyond future emissions rates, there are two big uncertainties on how fast the climate will warm. One is climate sensitivity, which is the measure scientists use to calculate how much the climate will warm as CO2 increases. It’s tricky to measure, because as the Earth heats up, it tweaks the climate dynamics in subtle ways, changing cloud cover, wind and rainfall patterns, and ocean circulation, among many other things. And all of this can impact warming.

Hamburg, Iowa: Historic flooding, due to climate change, rocked the Midwest last spring. Photo credit: Scott Olson/Getty Images Scott Olson/Getty Images

According to Hausfather, the real uncertainty lies with clouds, which are notoriously hard to capture in models, and have a big impact on the Earth’s temperature (high thin clouds trap heat, while low thick clouds shade and cool the Earth). Hausfather points out that the latest climate models, which use more-sophisticated cloud-modeling techniques, are showing a higher climate sensitivity, with potential warming of as much as 5 C if we double the CO2 in the atmosphere. These new climate-model runs are still in progress and, thus, inconclusive, but this is definitely not good news.

The other big uncertainty about our climate future has to do with tipping points. The latest research is showing some Earth systems may be more resilient than most people thought. The Gulf Stream system, for example, “has been slowing down in recent decades,” says Gavin Schmidt, head of NASA’s Goddard Institute for Space Studies. “But I don’t think anyone is worried about it shutting down anytime soon.” It’s the same with the melting of the permafrost in the Arctic: The more the permafrost warms, the more methane it releases, the more it warms the atmosphere — but none of the climate scientists I talked to believe there is a point when it runs away with itself. Similarly with the Amazon rainforest: As warming combines with deforestation, parts of it may turn into more of a savannah-like ecosystem. “But it’s not like there is a sudden crash and the entire Amazon disappears,” says Hausfather.

On the other hand, the more scientists learn about what’s happening with the West Antarctic Ice Sheet, the more unstable it looks. Earlier this year, researchers in Antarctica found evidence of warm water directly beneath the glacier, which is not good news for the stability of the system. Eric Rignot, a scientist at NASA’s Jet Propulsion Laboratory and one of the top ice scientists in the world, believes that the West Antarctic Ice Sheet is beyond its tipping point and in the midst of an irreversible collapse. As Rignot put it recently, “The fuse has been blown.”

When you look at images of the bush fires in Australia or the cracking ice shelves in Antarctica, it’s easy to think that it’s too late to do anything about the climate crisis — that we are, for all intents and purposes, fucked. And it’s true, it’s too late for 182 people who died from exposure to extreme heat in Phoenix in 2018, or for 1,900 people in northern India who were swept away in extreme floods in 2019, or the 4 million people who die each year around the world from particulate air pollution caused by our dependence on fossil fuels. And the way things are going, it’s probably too late for the glaciers on Mount Kilimanjaro, for large portions of the Great Barrier Reef, and for the city of Miami Beach as we know it.

But the lesson of this is not that we’re fucked, but that we have to fight harder for what is left. Too Late-ism only plays into the hands of Big Oil and Big Coal and all the inactivists who want to drag out the transition to clean energy as long as possible. Too Late-ism also misses the big important truth that, buried deep in the politics and emotion of the climate crisis, you can see the birth of something new emerging. “The climate crisis isn’t an ‘event’ or an ‘issue,’ ” says futurist Alex Steffen, author of Snap Forward, an upcoming book about climate strategy for the real world. “It’s an era, and it’s just beginning.”

This new era might be arriving more quickly than most people think. According to a new poll from the Yale Program on Climate Change Communication, nearly six in 10 Americans are now “alarmed” or “concerned” about global warming. Political support for the Green New Deal is rising as fast as the price of clean energy is falling. Greta Thunberg and Rep. Alexandria Ocasio-Cortez have inspired a new generation of climate activists who see the crisis as an opportunity to create a fairer, more equitable society. Germany, the industrial powerhouse of Europe, plans to shut down all coal plants by 2038. In the U.S., the coal industry is in free-fall. Larry Fink, the CEO of BlackRock, the financial giant that manages about $7 trillion in assets, acknowledged in a letter to shareholders that climate change is now “on the edge of a fundamental reshaping of finance.” Jim Cramer, CNBC’s notoriously cranky Wall Street guru, said in January, “I’m done with fossil fuels. … We’re in the death-knell phase.  .… The world has turned on them. It’s actually kind of happening very quickly.”

“I don’t have any doubt that we will take action on climate,” says Steffen. “But it won’t be the old-fashioned version of social change. It won’t be an orderly transition. It won’t be the climate version of the civil-rights movement. It will be more like the Industrial Revolution — a huge social and cultural and economic transition, which will play out over decades, and with no clear leadership and nobody in control.” In Steffen’s view, climate doomers are as blind as climate deniers. “The apocalyptic is in its very heart a refusal to see past the end of an old worldview, into the new possibilities of the actual world.”

I think Steffen is right. Whenever I feel like we’re fucked, I talk to landscape architects like Susannah Drake, who recently completed a preliminary redesign of the National Mall Tidal Basin in Washington, D.C., that will help restore a more natural ecosystem and embrace the rising waters of the Potomac River. I talk to entrepreneurs like Bill Gross, who has figured out a technology that uses mirrors to concentrate sunlight hot enough to manufacture concrete and steel. I talk to kids on school climate strikes who are determined to hold polluters and politicians accountable for trashing their future. Writer Mary Annaïse Heglar, who grew up in Alabama and Mississippi, sees the climate fight as part of a centuries-long battle for racial and social justice. “I don’t care how bad it gets,” she tweeted recently. “I don’t care how many thresholds we pass. Giving up is immoral.”

Like many people on the front lines of the climate fight, Heglar bristles at lazy questions about what gives her hope. “I think hope is really precious, and the most precious thing about it is that you have to earn it,” she tells me. “So, usually when people are asking me what gives me hope, what they really mean is, ‘Give me hope,’ and I can’t do that for you. No one can do that for you. You have to go out and make your own hope. And so that means I hope you get involved. The type of hope I have is that I hope you get off your ass.”