Climate change: new research highlights that policymakers adopt scientific information conservatively

New research highlights that exposure to climate models’ predictions affects policymakers and climate negotiators less than the informed general public. But the right presentation format can improve forecasts’ effectiveness.

These are the findings  of research involving academics from Bocconi University, Fondazione Eni Enrico Mattei (FEEM), Princeton University, IÉSEG School of Management (LEM CNRS), Fordham University, and Politecnico di Milano and publisihed  in the article “COP21 Climate Negotiators’ Responses to Climate Model Forecasts”, (by Valentina Bosetti, Elke Weber, Loïc Berger, David Budescu, Ning Liu, Massimo Tavoni, in Nature Climate Change, doi: 10.1038/nclimate3208).


Professor Loïc BERGER

The group of researchers, including Prof. Loïc Berger from IÉSEG, tested how a unique sample of policymakers and negotiators at the Paris COP21 conference updated their beliefs on year 2100 global mean temperature increases in response to a statistical summary of climate models’ forecasts. They randomized the way information was provided across participants using three different formats similar to those used in Intergovernmental Panel on Climate Change (IPCC) reports.

In spite of having received all available relevant scientific information, policymakers adopted such information very conservatively, assigning it less weight than their own prior beliefs. However, providing individual model estimates in addition to the statistical range was more effective in mitigating such inertia.

The experiment was then repeated with a population of European MBA students who, despite starting from similar prior positions/beliefs, reported conditional probabilities closer to the provided models’ forecasts than policymakers.

View the advance online publication of the article on the Nature Climate Change website.

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