When weather disaster strikes, observers near and far ask the same question: Climate change—is it or isn’t it?
The simplest answer, yes, lacks specificity. All weather is a joint human-nature venture, because we’ve made the atmosphere hotter than it’s been in 125,000 years. Disasters are nothing new. Assigning blame for them is.
A breakthrough out of the U.K. is providing better, more nuanced answers faster with powerful implications for citizens, first responders, and the media.
Friederike Otto is at the heart of it. Otto is a climate scientist at Imperial College London and co-leader of World Weather Attribution, a research collaboration that quickly analyzes if or how climate change has made extreme weather somehow worse—more intense, more likely, or deadlier. It’s a small, nimble, and—because of a current lack of funding—mostly volunteer effort assembled to bust science out of the academic quad and let a curious public know when climate change affects them in the most direct and personal way. It’s also beginning to help courts answer the more pointed question: Who, specifically, is responsible?
WWA has run more than 40 analyses over the past six years, answering specific questions about climate change’s impact on weather with even more specific numbers. A South African drought in 2015-2016 was three times likelier because of the lack of rain. When Hurricane Harvey hit Texas in 2017, its rainfall was 15% more intense and about three times more likely to occur. Last year’s headline-grabbing Siberian heat wave? That was 600 times likelier in our new climate.
These extreme events, of course, don’t happen on anybody’s schedule. Christmas week 2019 found Otto settling into a new house in Oxford, hanging out with housemates, and chatting on the phone with family in Germany who spoke, oddly enough, about fires on the other side of the world, in Australia. “They are not usually people who talk about extreme weather unless it’s happening in their backyard,” she says.
Within days she realized that, holidays or not, protracted Australian fires demanded attention in the two ways the group was designed to deliver: making reliable conclusions fast and informing the media cacophony. Otto and Geert Jan van Oldenborgh, a Dutch climate researcher and co‑head of WWA, phoned Australian colleagues on New Year’s Day with a tentative plan to test immediately for climate fingerprints; in each study they form partnerships with local researchers for their expertise.
“There is obviously a strong need for some scientific evidence in this debate,” Otto told the group, “because at the moment, everyone is just making wild assumptions about the origins of this fire.”
Over the next several weeks, the team would conduct science at the speed of fire. This new kind of science was designed to improve public understanding as much as deepen scholarly knowledge. It’s necessary, because the biggest gap in climate communication isn’t between people who heed science and people who disregard it, says Katharine Hayhoe, chief scientist at the Nature Conservancy. It’s between those who think climate affects only other countries and future generations and those who understand that it already affects them.
“We scientists used to say, 10 years ago, we cannot attribute a single event to the changing climate,” says Hayhoe, who’s not involved in WWA. “Now we’re actually able to say, ‘Hold my beer for a couple of weeks, and then I can tell you.’ Attribution is really important because it directly addresses the psychological-distance gap in public opinion.”
How they do it and what they find is breaking ground for a scientific field that didn’t exist a decade ago.
The only thing that may be more surprising than the speed with which event attribution has developed in recent years is the unusual route Otto took into climate science—via a doctorate in philosophy.
“I’m definitely an outsider,” she says. “I didn’t know how you would evaluate a climate model. I didn’t know the people who were highly regarded in the community. I just didn’t notice when I disregarded conventional wisdom. And because I didn’t know the community, I didn’t care what they think about me, at least at the beginning.”
Otto is 39 and has long, dark-blond hair that she often wears swept up into a bun. Her left eyebrow is pierced, and on her left wrist, next to a metal watch, sit three brightly colored plastic bracelets, one with dicelike white cubes that bear the letters “O-T-T-O.”
When she left high school in Kiel, Germany, she had poor grades and thick skin. Bullied and sometimes a target of misogynistic epithets, she emerged alert and unafraid of necessary confrontation. Bad grades meant “only the unpopular subjects were open to me” in college, she says. “It was basically physics or engineering, and physics was the lesser of the evils.”
What she liked about physics were the eternally tough questions: What exactly can we know? What can’t we know? After a masters in theoretical physics, Otto found herself drawn to skeptical inquiry and discovered it had extremely practical lessons that can “ground science more in reality,” she says. Her Free University of Berlin graduate work in philosophy of science has made her a permanent “broken record” about the importance of language and clarity when scientists communicate across disciplines or to the public—both of which define WWA. “This sounds trivial, but it’s really hard in practice.”
Otto then joined Oxford’s Environmental Change Institute in 2011—her home until this month— just at the dawn of an untested new subfield of climate research that needed an interpreter who understood the practical side of science and the centrality of clear language. She took on the job of putting cutting-edge work into climate-fueled disasters before the general public.
“There’s a certain fearlessness Fredi’s shown in making it happen,” says Peter Stott, a science fellow in climate attribution at the U.K.’s Met Office.
Extreme weather attribution began with a scientist wondering if anyone would ever be sued for climate change.
As floodwaters lapped up to his kitchen door in January 2003, Myles Allen, a climate scientist at Oxford, wrote an article for the journal Nature asking if courts would ever deliver accountability to the polluters responsible for warming-induced weather disasters. Or, as he put it: “Who to sue when the house price falls?”
This big question is now routinely answered in the affirmative by the existence of dozens of such lawsuits around the world. Still unresolved is how many suits will be successful. More than 1,500 climate-related cases have been filed globally, according to a database maintained by Columbia University’s Sabin Center for Climate Change Law.
Colleagues took note but saw the article “Liability for Climate Change” as largely speculative. “To be honest, I don’t think that any of us at that time thought that it was going to become practical as quickly as it did,” Stott says.
Several months later, Stott was on vacation when temperatures began to spike, not only where he was in Italy, but up through France and across the channel into the U.K. More than 70,000 people died from heat-related causes across Europe that summer. The heat wave’s scale and destruction changed Stott’s thinking. He teamed with Allen and a colleague to produce the first major study attributing an extreme-heat event to climate change. It took more than a year to publish their conclusion that greenhouse gas had made the disaster twice as likely.
The climate science profession didn’t embrace event attribution immediately. Some still grumble over the speedy and stripped-down analysis necessary just to publish something that hasn’t yet gone through peer review. WWA’s success has come in part from using a peer-reviewed process—even if the rapid analyses themselves aren’t formally published for a year. A 2012 workshop at Oxford introduced the field to a broad range of professionals. “They asked user groups whether they would be interested in attribution results, and pretty much all of them said no,” Van Oldenborgh says. There were two notable exceptions: lawyers and journalists.
In the same year, Otto first drew attention from fellow researchers by firing off a salvo in a prominent journal. In 2010, Russia suffered an historic heat wave that killed 55,000 people. She’d come across two studies about it with conclusions so different they might have concerned separate events. One determined that the heat wave was “mainly natural in origin”; the other found that, without climate change, “the July 2010 heat record would not have occurred.” The contradiction was stark and begged for resolution. Otto’s expertise for the first time found its complement in climate statistics, when she paired with Van Oldenborgh. The team dismantled the two Russia studies and identified the issue. “They were actually both right. They just framed the question very differently,” Otto says. “That got me totally hooked.” How to define extreme events—in geography, time, measurements—would later become critical to WWA’s work.
Otto was all-in, and she wasn’t alone. Science had established that weather attribution was possible. News media had demonstrated an appetite for results. Even that wasn’t enough until an opportunity arose.
Climate Central, a research nonprofit, had taken a leading role in event attribution. It raised money to organize a program and in 2014 reached out to Allen, who was then still leading rapid-attribution efforts, and Otto, who would take it over from him.
Climate Central had a request that would help transform the science: “This is actually a really, really important way of bringing home climate change to people,” Otto recalled them saying. “Can you do it faster, please?”
She could, and the era of fast climate calls had begun.
Bush fire projections in 2019 had looked dire, and by early September, Australia’s “Black Summer” had begun. By the time the devastation ended, in March 2020, 92,000 square miles of forest had burned, or more than 13 times the extent of the unprecedented 2020 California fires.
In parallel to the destruction, conflict erupted across Australia’s media, in which, as 2019 moved to a close, there arose false and politically tinged charges that arson was responsible for the fires.
By the first day of 2020, Australia faced two conflagrations: the literal one, raging across the landscape; and the political one, manufactured by politicians, media, and online trolls. With more land on fire than ever and public discussions led astray by disinformation, WWA entered the fray to discover—as Australian scientists predicted in 2008—whether climate change was actually “directly observable by 2020.”
Heat waves, the simplest of the events the group looks at, can take only a week to study. But bush fires combine heat, drought, geography, and the general shift in weather toward fire-friendly conditions.
When the team needed to figure out the Australian fires, they started by defining their area of interest—literally drawing on a map a trapezoid around the country’s afflicted southeastern area. Once they identified the specific coordinates of interest, they pieced together the area’s long-term climate history, relying on heat and drought records and an index of fire weather. Next came simulations of the disaster on 11 groups of climate models, in virtual worlds with and without global warming.
They’d never studied bush fires before, because of their complexity. It took about two months, mostly looking at spreadsheets, charts, and maps, to reach their findings: Climate change made the heat twice as likely and increased fire weather by 30%.
They published their analysis a week after the fires ended in New South Wales, just as a national bush fire investigation was beginning its work. It was another advance for just-in-time science.
World Weather Attribution earns the biggest and most regular headlines, but other groups are also at work analyzing “angry weather”—the title of Otto’s 2020 book. The climate science and policy website CarbonBrief.org counted more than 350 peer-reviewed studies earlier this year. Since 2012, Stott and colleagues have edited an annual research collection called Explaining Extreme Events From a Climate Perspective.
An international project in many ways similar to WWA never took off, Van Oldenborgh says, because the team was made up only of scientists focused on meteorology, not a hybrid team of scientists, a humanitarian group, and communication experts. “We just try to figure out exactly what the question is that society wants answered,” he says.
WWA is rarely the same organization twice because Otto, Van Oldenborgh, and several other regular members also tap regional experts for each new study. Interest in the organization’s work among scientists is growing. Ten people worked on the group’s August 2017 analysis of Hurricane Harvey. Twenty-seven authored its report on June’s North American Pacific Coast heat wave and a record 39 on its most recent report on July’s European flooding.
Otto and Van Oldenborgh, who works at the Royal Netherlands Meteorological Institute, have regular collaborators from France’s Institute Pierre-Simon Laplace and ETH Zurich. The Red Cross Red Crescent Climate Centre, which has worked with WWA from its beginning, helps vulnerable people anticipate, prevent, or cope with disasters.
Rapid-event attribution has emerged quickly from humble origins to marquee attention in the Intergovernmental Panel on Climate Change’s most recent report, in which the United Nations-backed scientists, including Otto and several WWA colleagues, state that “event attribution is now an important line of evidence for assessing changes in extremes on regional scales.”
When Claudia Tebaldi, an Earth scientist at Pacific Northwest National Laboratory, encountered the Oxford team’s ideas for rapid extreme weather attribution in 2012, she was initially skeptical that a push would contribute in a significant way to new science.
But by combining multiple sources of evidence, different methods, observations, and model experiments, WWA has brought rigor to a standardized process and become an influential research group. Its analysis of the North American Pacific heat wave drew at least 3,300 news articles worldwide. It was completed within eight days of the June 29 record-breaking high temperature of 49.6C (121.3F) in Lytton, B.C.—which was consumed by wildfire on the following day.
“Fortunately or unfortunately, the fact is that global warming is becoming such a driver that even that fairly simple approach is good enough,” Tebaldi says. “And then the other more sophisticated, slower, and more complicated studies will take place.”
Most of WWA’s analyses find an overwhelming climate influence on an extreme weather event. But not all of them do—which is also useful. The goal is to learn what’s making disasters worse, so people and communities can better withstand them. A drought in southeastern Brazil in 2014-15 turned out to be fueled more by population growth and water use, the group found.
“We shouldn’t fool ourselves, blaming everything on climate change, when there are other triggers that are also important to know about,” says Maarten van Aalst, director of the Red Cross Red Crescent Climate Centre and a climate scientist at the University of Twente in the Netherlands.
More than a year went by between WWA’s analysis of the Australian fires and its conclusion that the recent North American Pacific coast heat wave would’ve been “virtually impossible” without greenhouse gas pollution. The pandemic was one reason that attribution work slowed. The other: no money.
WWA’s success has not yet turned into secure funding. “We just sort of do this on top of our other work, and we do it because we think it’s important,” says Roop Singh, climate-risk adviser at the Climate Centre. “We think it’s interesting science, and we think that it’ll be useful when we put it out into the world.”
It wouldn’t take much, Van Oldenborgh says. World Weather Attribution is one of the world’s most influential research groups, and it wants to hire three postdocs and a project manager. Ultimately the goal is to standardize as much attribution as the group can, so weather bureaus can offer it as a regular service, freeing up WWA to focus on developing countries and complex extremes.
There’s all this great new climate research, and courts are missing it. That’s what Otto, one of her graduate students, and several other colleagues found in June, according to their research into how courtroom evidence “lags considerably behind the state of the art.”
“You actually can prove the whole causal chain from emissions, via global mean temperature and/or the climate system, to actual concrete damages that cost money, affect lives, and livelihoods,” Otto says. “And that hasn’t really filtered through, definitely not to the courts.”
The team analyzed 73 cases from 14 countries that might benefit or might have benefited from this rapidly maturing field. Almost three-quarters of these cases cited no evidence from attribution science. Their recommendations included simple steps such as putting lawyers and scientists together to talk. Otto and other climate researchers have already filed friend of the court briefs in several cases.
There are several kinds of climate cases. Citizens sue local governments for not regulating greenhouse gases or protecting them from impacts. Local governments sue nations for not acting. Various groups have tried to sue fossil fuel companies for deceiving consumers and investors over climate change.
Many cases disappear or get stuck for years before climate science even enters the picture. There are cases in which U.S. cities or counties are suing energy companies in state courts that have been held up while defense lawyers try to move them to friendlier federal courts. Several high-profile cases have dealt losses to the plaintiffs, including a 2018 New York state securities lawsuit against Exxon Mobil Corp. Climate activists’ wins have tended to come in Europe.
As a general matter, science isn’t new to the courtroom. It’s spurred years of litigation in product liability lawsuits and toxic tort cases, in which a plaintiff files suit over alleged harm from tobacco, opioids, asbestos, pesticides, chemicals, and a world of other poisons. Climate lawsuits share some characteristics with these kinds of disputes: So many people are responsible, it’s hard to single out anyone.
The way courts in multiple countries may deal with these cases is to ask, as U.K. courts do, whether the harm would have occurred “but for” the defense side, says April Williamson, a lawyer for the climate program of legal nonprofit ClientEarth.
“The way that tort law works is that you’re trying to put the claimant in the position that they would have been in if the damages had never happened,” she says.
From there, the thinking goes, courts in the U.K. can assign responsibility through a kind of “market share” analysis—the more carbon dioxide you’ve emitted, the bigger your share.
U.S. courts in particular may reject novel analysis that spreads blame that everyone shares to a few, albeit major emitters. Lower courts have never pushed back at Massachusetts v. EPA, which read climate change as a regulatory or congressional problem and less one for the judiciary, says Josh Macey, an assistant professor at the University of Chicago Law School.
Besides, he says, given the scale and expense of energy and industrial systems that need fixing—building clean power generation and transmission—“environmental attorneys going to court and suing Exxon is not going to address climate change.”
Van Oldenborgh recently told Otto that when they start a major study—the Australian bush fire paper in particular—he often bolts awake from nerves around 4 a.m. to run through the numbers in his head. She responded that she also wakes up from nerves at 4 a.m. to run through the conclusions based on his numbers.
The two complement each other the way a lyricist and songwriter do. They’re a “dream team,” Van Oldenborgh says, and yet an unlikely one. She’s “a very fashion-conscious woman in her late 30s,” and he’s an “old guy” who’s avoided taking on responsibilities that would distract him from scientific work. But they’re “both very obsessed with getting things correct,” he says. “She’s really good with words, and I’m pretty good with numbers.”
Van Oldenborgh, 59, who raised extreme weather attribution with Otto from a tiny unknown endeavor to a tiny internationally celebrated endeavor, has also struggled for eight years with an incurable cancer, called multiple myeloma. After surviving a recent close call, he’s undergoing a new treatment that’s effective for an average of nine months—“which at my stage is really good,” he says.
“I really hope I get another year or two or whatever to continue this kind of work,” he says. “In a way, it’s the same as climate. There’s scenarios in which you cannot assign probabilities.”
To contact the author of this story:
Eric Roston in New York at firstname.lastname@example.org
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