The Seine River, which runs through the heart of Paris, recently hit a 34-year high. Is climate change to blame?

Of Climate Science and Peer Review

A few weeks ago, torrential rains caused heavy flooding in Germany and France, forcing the evacuation of thousands and killing at least nine. Within days of the natural disaster, a group of climate researchers published a scientific paper concluding that the flooding, at least in France, had been made far more likely by climate change.

The study used state-of-the-art modeling and the work was performed by a group of highly regarded climate researchers.

It was not, however, peer reviewed.

Scientists were quick to publish research — prior to peer review — linking flooding in France to climate change. Is it an effective strategy? (Visual by

Scientists were quick to publish research — prior to peer review — linking flooding in France to climate change. Is it an effective strategy? (Visual by

Heidi Cullen, one of the study’s co-authors and leader of the World Weather Attribution program, noted that while the un-reviewed analysis was released to the public, it had also been submitted to the journal Hydrology and Earth Systems Sciences, which is peer reviewed. The problem, Cullen said, is that this sort of work needs to become part of the conversation more quickly than the formal peer review process typically allows.

“It’s generally in the immediate aftermath of these events that important decisions get made,” she said. “If we can inject a rigorous objective analysis into that conversation, we’re hoping to further that conversation and make sure it’s informed by the best available science.”

It’s not unusual, of course, for scientists to share results ahead of formal peer review and journal publication, whether as working papers circulated among colleagues for feedback, or as preprints uploaded to popular repositories like the, which focuses on physics and mathematics research, and the newer, life sciences research archive

But what Cullen and her colleagues are doing is, in at least one important way, very different. The World Weather Attribution program, in addition to making studies available before publication, is writing up non-technical summaries of their analyses that specifically target a popular audience.

The feeling seems to be that on an issue of such importance — and one where disinformation and denialism still percolate within the public discourse — climate researchers simply cannot afford to wait the weeks, months or even years that the scientific peer review and editing process often requires.

It’s a feeling that has animated other scientists, including the prominent climatologist James Hansen. Last year, his team published — ahead of peer review — a troubling new analysis on potential sea level increases associated with rising global temperatures. The goal was to influence world leaders ahead of the looming climate summit in Paris, and the study drew both headlines and some criticism from fellow scientists who called it speculative and irresponsible. That paper was eventually peer reviewed and formally published, albeit with some of its initial findings tempered — and a lingering air of activism that made some scientists and journalists uncomfortable.

The question for Cullen and her colleagues, then, is whether this sort of scientific activism is truly effective. After all, other research has suggested that lingering skepticism and indifference toward climate science has little to do with a lack of scientific understanding among the general public, and is rather a product of social tribalism, where competing worldviews and value systems shape public attitudes far more than scientific literacy.

In this light, suggests Andrew Hoffman, a professor at the University of Michigan’s Ross School of Business who has researched the role of academics in public and political discourse, the tactic might actually prove counterproductive.

“What if [the study] is rejected by peer review? What then?” Hoffman asked. “It could be very embarrassing and damaging. As tempting as it is and as urgent and passionate as the researchers are, it opens up another line of attack for those who want to discredit the science.”

The Seine River, which runs through the heart of Paris, recently hit a 34-year high. Is climate change to blame? (Visual by

The Seine River, which runs through the heart of Paris, recently hit a 34-year high. Is climate change to blame? (Visual by

Cullen acknowledged those risks, though she said her team wasn’t circumventing peer review so much as participating in a crucial scientific discussion as it’s happening — and making that discussion available to the public. “I think we’re in uncharted territory, a new place that the scientific community finds ourselves in,” Cullen said. “There are going to be risks associated with doing this, but we feel like we’re not bypassing the stage of writing up the paper and submitting it for peer review.”

Cullen also noted that the recent analysis of European flooding — which included work by a team of scientists from the University of Oxford’s Environmental Change Institute, Princeton University’s Climate Central, the Royal Netherlands Meteorological Institute, the University of Melbourne, and the Red Cross Red Crescent Climate Centre — is based on time-tested methodologies that have been peer-reviewed in past studies.

“We are all actually still very much wearing the hat of scientist,” Cullen said, “not just individuals speaking about our feelings on climate change and what should or should not be done about it. We’re actually sharing results. The message, if you will, is going to be dictated by the analysis.”

Just who that message will ultimately reach and how it will be received, however, remains an open question. Hoffman, for example, pointed to the “Six Americas” study out of Yale University, which identifies several distinct categories of American attitudes toward the climate issue. They range from the alarmed, concerned or cautious at one end of the spectrum, to the disengaged, doubtful and dismissive at the other.

“One of the first rules of effective communication is to ‘know thy audience,’” the research team at Yale’s Center for Climate Communication note. “Climate change public engagement efforts must start with the fundamental recognition that people are different and have different psychological, cultural, and political reasons for acting – or not acting – to reduce greenhouse gas emissions.”

Given this, Hoffman says it’s important to target scientific communications strategically. “That undecided middle is where we have to focus,” he said, adding that he does believe that scientists have an obligation to make their work known and understood by the public. Given the prevailing stratification in attitudes, however, publicizing results ahead of peer review can have unpredictable results.

“There’s an idea that creators of knowledge should not cross into advocacy,” he said, “that if we cross that fuzzy line, we lose the objectivity of the academia and we start getting into very tricky territory. We’re still trying to figure out where that line is.

“I appreciate the tension of the people that want to get material out before peer review,” he added, “but it’s a slippery slope.”