Forensic Climate Attribution Has Arrived

By Daniel Aronson

Circumstantial evidence has always been a tricky affair. A fingerprint is found near the scene. A glove, perhaps, thought to belong to the suspect. A phone record appears to implicate an accomplice. There was no eyewitness, but inference points to the culprit.

Not all circumstantial evidence, however, is created alike. The advent of DNA in forensics gave the courts a powerful scientific tool for attributing blame or establishing innocence, often with a very high degree of certainty.

But this science was not always the accurate, systematic and broad-based field it is today. It took years of trial and error, diagnostic mistakes, and false positives. Many thousands of scientists around the world catalogued, sequenced, experimented, checked and rechecked results, and developed new techniques and technologies. Today, DNA evidence is routinely used to screen out the innocent and implicate the guilty.

Up to now, climate change has often presented the same types of problems as crime scenes with only circumstantial evidence. There has been a hurricane, say, that destroyed much of a major U.S. city and killed hundreds, or an unprecedented heat wave across Europe that also took many lives.

But what caused them? Climate change! says one group. Nature! screams another. There have always been storms and heat waves!

Yet, as in genetics, the science, equipment, and climatological techniques have improved greatly over the years and “extreme event attribution is rapidly advancing due to improved understanding of extreme events, improved modeling,”[1] etc.

As a 2016 report[2] by the National Academies of Sciences, Engineering and Medicine asserted, “In the past, a typical climate scientist’s response to questions about climate change’s role in any given extreme weather event was ‘we cannot attribute any single event to climate change.’ The science has advanced to the point that this is no longer true as an unqualified blanket statement.”

In fact, at this point, “the existing body of detection and attribution research is sufficiently robust to support the adjudication of certain types of legal disputes,” according to the exhaustive, 238-page study of attribution by a team from the Columbia Journal of Environmental Law.[3]

Using climate forensics – what climatologists call ‘climate change attribution,’ experts can now sit in courtrooms just as DNA experts do, and say with “increasing statistical certainty,”[4] that X event was increased in likelihood and severity by anthropogenic climate change.

In an analysis of “high-resolution computer simulations,” scientists were able to attribute[5] the tropical storm that devastated Houston in 2019 to human-generated climate change which, they said, had made the storm as much as 2.6 times more likely and up to 28% more intense.[6] Indeed, “several studies have found that certain extreme events could not have been possible in a pre-industrial climate,” according to the Columbia report.

And recently the New York Times reported[7] that scientists had pinned a specific percentage of the damage and severity of the 2019 Australian wildfires on climate change. The scientists involved belong to World Weather Attribution,[8] a collaboration of scientific, meteorological and educational institutions that was “initiated in late 2014 after the scientific community concluded that the emerging science of extreme event attribution could be operationalized.”

A 2019 Carbon Brief[9] analysis of “more than 230 peer-reviewed studies looking at weather events around the world” concluded that “68% of all extreme weather events studied to date were made more likely or more severe by human-caused climate change. Heatwaves account for 43% such events, droughts make up 17%, and heavy rainfall or floods account for 16%.”

Thus armed, the battle over climate change is shifting from courtroom analogy to actual courtroom drama.

 As we forecast this January in Blame: The Worm Will Turn in 2020,[10] as costs and damages from human-driven climate events continue to rise dramatically, so will lawsuits against Big Carbon industries, and governments who have supported fossil fuels.

As the authors of the Columbia study point out in their executive summary,[11] “In several foreign cases, plaintiffs have successfully used attribution science to demonstrate that a government’s failure to regulate greenhouse gas emissions at adequate levels endangered the public health and welfare of citizens within the country, and thus the government had violated its duty of care to its citizens.”

While there are also dozens of climate cases working their way through the U.S. courts, as we noted in Blame, “for those considering the current state of the U.S. judiciary, we suggest that such decisions are just as likely to happen outside the U.S.” Such extranational decisions, however, could “still affect multinational companies, including those based in the U.S.”

Interestingly, notes Vox,[12] in the U.S. courts, “climate science itself isn’t up for debate… in nearly all (U.S.) cases, the parties agree on these facts: Greenhouse gases from burning fossil fuels are heating up the planet, which in turn is fueling sea level rise, more extreme weather, and changes in the overall climate.” Rather, the cases hinge on “fundamental interpretations of law” rather than the facts of climate change.

The tobacco industry once found themselves in a similar pickle, insisting they didn’t know their product’s dangers, and burying information to the contrary as early as the 1950s.

As a result, for a time they were able to fend off most of the suits brought by individuals alleging fraud and other charges. Eventually, however, as smoking-related cancers and health care costs mounted, a 46-state suit was settled[13] for more than $206 billion over 25 years covering, along with restrictions on marketing and sales, the dissolution of key industry groups. Many successful class-action and individual suits have followed.

A key difference here is that, while there is overwhelming scientific evidence that smoking causes cancer in general, it is difficult to attribute any given case to that cause. Climate change attribution can now, in many cases, point to what Carbon Brief labelled, “the human fingerprint on extreme weather, such as floods, heatwaves, droughts, and storms.” And the science will likely continue to improve.

Climate attribution can also be used “by plaintiffs to demonstrate that they have suffered an injury as a result of anthropogenic climate change,”[14] and that greenhouse gas emitters are responsible.

In any courtroom, some will continue to believe in guilt or innocence – regardless of proof – to suit their own beliefs and agendas. But the proof is nonetheless there to allow a verdict beyond the legal standard for it. And that is a powerful development. 

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Daniel Aronson is the founder of Valutus, a startup consultancy focused on sustainability measurement, valuation, strategy, and tools. He is the author of the forthcoming book, The Value of Values.

___________________ References

[1] Columbia University Press, The Law and Science of Climate Change Attribution, Executive Summary, 2020

[2] National Academy of Sciences, Engineering and Medicine, Attribution of Extreme Weather Events in the Context of Climate Change, Report, 2016

[3] Columbia University Press, The Law and Science of Climate Change Attribution, 2017

[4] MIT Technology Review, Feb. 2020

[5] World Weather Attribution, Rapid Attribution of Extreme Rainfall in Texas from Tropical Storm Imelda, Sept 27 2019

[6] Ibid

[7] The New York Times, Climate Change Affected Australia’s Wildfires, Scientists Confirm, March 4 2020

[8 ] World Weather Attribution

[9] Carbon Brief, Mapped: How Climate Change Affects Extreme Weather Around the World, March 11 2019

[10] Valutus.com, Blame: The Worm Will Turn in 2020,Feb 2020

[11] The Law and Science of Climate Change Attribution, Executive Summary, 2020, Columbia University Press

[12] Vox, Pay Attention to the Growing Wave of Climate Change Lawsuits, June 4 2019

[13] NOLO, Tobacco Litigation: History and Recent Developments

[14] The Law and Science of Climate Change Attribution, Executive Summary, 2020, Columbia University Press