Communicating uncertain future climate risk: Lessons learned from adaptation and disaster risk practitioners in Madagascar

Climate information is increasingly being produced and shared as governments, businesses and individuals need to adapt to the changing climate. Yet, communicating uncertain climate change information to non-experts remains a challenge. The information that is currently made available to non-climate science specialists is too complex for them to understand and use. A key challenge in climate science is that estimating future change comes with uncertainties which are highly technical to non-climate specialists. Nevertheless, it is paramount that when climate information is shared and used, the limitations and uncertainties attached are well understood. This is particularly important amongst audiences that lack technical familiarity with climate science. Additionally, scientists and climate service providers do not have a common approach to represent the range of future change. Some scientists place an emphasis on probabilistic projections, meanwhile others focus on the full range of plausible futures.There has been a limited effort to assess whether the audience understands what the producer of the climate information intended. Testing or evaluating different methods and visualisations of communicating future climate information, and its related uncertainties, can provide insight into what is most effective. Isolating what is (mis)understood can shed light on how to effectively communicate future climate information. This study investigates the interpretation of different presentations of future climate information using a survey and discussion with 45 participants working within weather and disaster agencies in Madagascar. Icon arrays, climate risk narratives, key statements and verbal probability language was tested to provide insight into how practitioners understand different ways of communicating future climate information. Both probabilistic and plausible framings of uncertainty are considered to explore how participants interpret each.The percentage of participants that selected the correct answers across comprehension questions ranged from 24-82%. For the interpretation of verbal and numeric probabilities which was communicated as “virtually certain [99-100%]”, the correct numerical probability was selected by 24% of participants, highlighting the systematic misinterpretation of verbal and numerical probabilities. The climate risk narrative provided 3 plausible narratives, however, over a third of participants incorrectly believed there were 3 narratives to allow decision makers to select a narrative that is sector relevant. Some reasons for misinterpretation were provided by the participants such as confusing legends and icons, using their prior knowledge instead of the information document or experiencing cognitive dissonance. Meanwhile some expressed difficulty understanding due to lots of information while others requested additional insights, demonstrating the need for flexibility in design.This study has highlighted new ways of communicating climate risk as well as ineffective current practises.  Recommendations suggest that climate scientists and climate communicators should; include an explicit explanation of why there are multiple climate risk narratives; reconsider the use of numeric and verbal probability expression given they are commonly misinterpreted and consider that an individuals’ prior knowledge influences their interpretation of new information.