Assessment of how climate scientists communicate risk shows imperfections, improvements

BUFFALO, N.Y. – Scientists have long struggled to find the best way to present crucial facts about future sea level rise, but are getting better at communicating more clearly, according to an international group of climate scientists, including a leading University at Buffalo expert.

The consequences of improving communications are enormous, the scientists said, as civic leaders actively incorporate climate scientists’ risk assessments into major planning efforts to counter some of the effects of rising seas.

Writing in Nature Climate Change[CN1] [VS2] [VS3] , the scientists review the language and graphics used in climate “assessment” reports between 1990 and 2021 by members of the United Nations’ Intergovernmental Panel on Climate Change (IPCC).

As one of the authors, Sophie Nowicki, UB Empire Innovation Professor in the Department of Geology, shares that communicating in ways that are both accurate and understandable can be difficult.  

“Because there are many stakeholders that use the IPCC projections for adaptation and planning policies, it is very important that we (the scientists) learn how to communicate our findings better,” said Nowicki, a core faculty member of the UB RENEW Institute, which develops solutions for complex energy and environmental issues.

According to Nowicki, conveying information about the potential range of future sea-level rise to those who will use this information to make decisions about long-term coastal planning and adaptation can be a challenging task, as there is a great deal of uncertainty about future sea-level rise.

“We really need clear definitions for the words that we use so that our findings can be as clear as possible for everyone,” Nowicki said.

The study “Communicating future sea-level rise uncertainty and ambiguity to assessment users,” finds that future sea-level change is characterized by both quantifiable and unquantifiable uncertainties.

“There’s quantifiable uncertainty, which can be measured and presented with a degree of confidence,” said Robert Kopp, a lead author of the study and a professor in the Department of Earth and Planetary Sciences at the Rutgers School of Arts and Sciences, “and then there’s ambiguity, a form of deep uncertainty that cannot be well represented quantitatively.”

The analysis shows aspects of sea level rise where the level of risk could be quantified have been presented accurately, informing public bodies effectively. But when conveying sea level uncertainties that have been and remain difficult to quantify, the language in the reports often has fallen short, either oversimplifying projections or conveying the information in a confusing manner, according to the analysis. Such language could lead policymakers to neglect the risks associated with possible high-end sea-level outcomes.

Ambiguity arises in situations in which analysts can interpret a common set of facts in highly divergent ways – or can’t interpret them at all, Kopp said.

The study contrasts the language used to convey ambiguities in the risk of late-century sea level rise in the IPCC reports in 1990, 1995, 2001, 2007, 2013 and 2021, along with the UN’s Special Report on the Ocean and Cryosphere in a Changing Climate issued in 2019.

In the First Assessment Report, released in 1990, the authors characterized a rapid disintegration of the West Antarctic Ice Sheet because of global warming as “unlikely in the next century.”

In contrast, in the Sixth Assessment Report, published in 2021, scientists warn that higher rates of sea level rise before 2100 could be “caused by earlier-than-projected disintegration of marine ice shelves, the abrupt, widespread onset of marine ice sheet instability and marine ice cliff instability around Antarctica.”

The report goes on to explain that the processes are characterized by “deep uncertainty.” It concludes: “In a low-likelihood, high-impact storyline, under high emissions such processes could in combination contribute more than one additional meter of sea level rise by 2100.”

Communicating complex risk scenarios to the public in an effective manner is an ongoing process. If the approach taken in the most recent climate report in 2021 is successful, it will be accurately reflected in future regional assessments and will ultimately be judged by policymakers, along with climate and social scientists.

It matters that scientists get it right, the study concludes.

The authors in the study, all of whom were involved with the Sixth Assessment Report, include those from UB and Brown University in the U.S., as well as others in China, France, Germany, Great Britain, the Netherlands, New Zealand and Singapore.