By Jennifer Dorroh
The emerging science that is increasingly able to determine how much of an extreme weather event is attributable to climate change may drive growth in climate liability suits, according to a new paper published in the Journal of Energy and Natural Resources Law.
The paper, by environmental lawyers Sophie Marjanac of ClientEarth and Lindene Patton of Earth & Water Law Group, is titled, “Extreme weather event attribution science and climate change litigation: an essential step in the causal chain?” And their conclusion is yes.
“Scientists are now able to better understand the drivers of extreme weather, and quantify the extent to which climate change shifts the goal posts of expected weather patterns,” the authors wrote.
The science of extreme weather attribution analyzes the relationship between extreme events and long-term climate disturbances such as volcano eruptions, solar variations, changes in land use and carbon emissions. It makes connections and predictions by using advanced—and rapidly improving—computational data to develop increasingly sophisticated climate models.
Recent attribution studies, for example, concluded that the rainfall from Hurricane Harvey, which devastated Texas last year, was up to 38 percent worse because of global warming. A collaborative effort, World Weather Attribution, has gathered a group of scientists dedicated to doing these studies rapidly after major weather events. The group concluded last year’s European heat wave was made at least four times more likely by climate change.
“We suggest that the science of event attribution may become a driver of litigation, as it shifts understanding of what weather is expected and, relevantly for law, foreseeable. This may have an impact on the duties of government actors as well as private parties,” Marjanac and Patton wrote. “We conclude that the first kind of litigation to emerge is most likely to arise from failures to adapt to, or to prepare for, our changing climate.”
One of the barriers to holding fossil fuel companies accountable for climate change is drawing a conclusive line between the impacts of global warming and the emissions that overwhelmingly drive it. Many of those impacts are related to extreme weather, including hurricanes or heavy precipitation events, heat waves and drought. So the ability to deduce how much climate change leads to these events is a crucial piece of the liability puzzle.
The paper, whose intended audience is lawyers, is part of Marjanac and Patton’s ongoing effort to bridge the gap between the way scientists and other professionals view uncertainty and risk. A previous paper, “Acts of God, Human Influence and Litigation,” which they co-authored with James Thornton, chief executive of ClientEarth, was aimed at scientists and published in the journal Nature Geoscience in 2017.
“We wanted to inform scientists about how lawyers and others use their data,” Patton said of the earlier paper. “This was not designed to change what they do, but we wanted them to see where and how their work affects the duties of other professionals.
“Scientists are taught to continue to seek the truth until they reach a 95 percent confidence level,” she said. Yet many other professionals, from actuaries to engineers, have the responsibility to weigh risks, which, by definition, involve uncertainty. “In those professions, it is critically important to be aware of risks even if scientists cannot be completely certain. When you’re making decisions about how long a facility is going to last, whether it needs a backup water source, you need to know,” said Patton, a former chief climate product officer for the Zurich Insurance Group.
Now, Patton hopes to help lawyers understand the way scientists express uncertainty. When lawyers started considering climate liability cases, “there was an apparent assumption by many lawyers that you couldn’t make decisions about adaptation because the science wasn’t clear enough,” she said. “But statistical certainty, especially with droughts and flooding, is now very high. It’s high enough that it impacts the responsibility and duty of licensed professionals.”
Kristin Casper, litigation counsel for Greenpeace’s climate justice and liability project, called Marjanac and Patton’s work “a must-read article for lawyers advising on climate change.
“With the rapid advancements in attribution science, governments and private parties can no longer claim that climate science is too general to act on,” she wrote in an email.
“Empowered with this growing body of science, affected people and communities will make increasing demands for governments and companies to take all steps to protect lives and livelihoods from the increasing risks of droughts, fires, heat waves, and storms.”
The climate change tutorial ordered by the judge in the San Francisco and Oakland climate liability suits touched on attribution science, but it was not extensively discussed.
“Extreme weather event attribution is central to some of the litigation that is going on right now,” said Michael Burger, executive director of the Sabin Center for Climate Change Law at Columbia University.
Asked whether extreme weather event attribution science will spur other climate liability lawsuits, he said, “That remains to be seen, but if one or more of the current set of public nuisance lawsuits currently being briefed succeed, we may well see more of them.”