Effective communication of uncertainty in the IPCC reports

Abstract

The Intergovernmental Panel on Climate Change (IPCC) publishes periodical assessment reports informing policymakers and the public on issues relevant to the understanding of human induced climate change. The IPCC uses a set of 7 verbal descriptions of uncertainty, such as unlikely and very likely to convey the underlying imprecision of its forecasts and conclusions. We report results of an experiment comparing the effectiveness of communication using these words and their numerical counterparts. We show that the public consistently misinterprets the probabilistic statements in the IPCC report in a regressive fashion, and that there are large individual differences in the interpretation of these statements, which are associated with the respondents' ideology and their views and beliefs about climate change issues. Most importantly our results suggest that using a dual (verbal-numerical) scale would be superior to the current mode of communication as it (a) increases the level of differentiation between the various terms, (b) increases the consistency of interpretation of these terms, and (c) increases the level of consistency with the IPCC guidelines. Most importantly, these positive effects are independent of the respondents' ideological and environmental views.

Analysis of uncertainty consideration in environmental assessment: an empirical study of Canadian EA practice

“…Our results indicate that EAs need to better reflect the complexity of environmental processes, the incompleteness of knowledge and the uncertainty of making predictions about the future impacts of a project than what is currently practiced. Consistent with Budescu, Por, and Broomell (2012) and Leung et al (2015), there is a need for uncertainty information to be documented in a way that can be easily and effectively transmitted to decision makers, the public, and other stakeholders À but also in a way that facilitates depth in understanding of the implications of uncertainty and how it will be addressed through EPPs, follow-up programs, and panel reports. In our study, when uncertainty was disclosed there was limited, and often superficial, discussion of the implications of the uncertainties.…”

Using Statistics to Quantify and Communicate Uncertainty During Volcanic Crises

“…: very likely) with quantitative specifications (e.g. : <90% probability) has been recommended, for example, to better understand results from Intergovernmental Panel on Climate Change (IPCC) (Budescu et al 2009(Budescu et al , 2012. Climate scientists working within the IPCC have adopted a lexicon to communicate uncertainty through verbal probability expressions ranging from "very likely", "likely", "about as likely as not unlikely", "very unlikely" and "exceptionally unlikely" to refer to probabilities (e.g.…”

“…There are numerous studies that demonstrate the importance of public education, pre-crisis education programmes, and risk perception to better understand scientific communication during crisis (e.g. Bird et al 2009;Budescu et al 2012;Dohaney et al 2015). Most of them agree that better educated populations on natural hazards understand better risk communication and behave in a more orderly way for managing a crisis.…”

The IPCC and treatment of uncertainties: topics and sources of dissensus

“…14,18,20,24,25,27,29,[31][32][33]45,47 Several aspects are raised. One aspect is that the use of calibrated language to communicate degrees of certainty in findings is not sensitive to or congruent with nontechnical perspectives.…”