For example, when a scientist at the Intergovernmental Panel on Climate Change (IPCC) says that an event is “very likely,” they mean that there is at least a 90 percent chance of the event occurring. Recent research found that British and Australian citizens interpreted this same phrase to include probability as low as 65 percent. To address this 25 percent difference, Emily Ho, David Budescu, Mandeep Dhami, and David Mandel, writing in Behavioral Science & Policy, built an evidence-based lexicon based on citizen survey responses instead of scientists’ jargon in order to improve the communication of information around climate change.
In their study, consistency in the interpretation of verbal probabilities increased by 63 percent in the United Kingdom and by 100 percent in Australia after using the new evidence-based lexicon. As the leading international body for the assessment of climate change established by the United Nations, it is concerning that the IPCC’s lexicon produced a mean interpretation consistency of only 27 percent in the UK and 25 percent in Australia.