Apocalypse now? Communicating extreme forecasts

Apocalyptic forecasts are unique. They have, by definition, no prior history and are observed only in their failure. As a result, they fit poorly with our mental models for evaluating and using them. However, they are made with some frequency in the context of climate change. We review a set of forecasts involving catastrophic climate change-related scenarios and make several observations about the characteristics of those forecasts. We find that mentioning uncertainty results in a smaller online presence for apocalyptic forecasts. However, scientists mention uncertainty far more frequently than non-scientists. Thus, the bias in media toward coverage of non-scientific voices may be 'anti-uncertainty', not 'anti-science'. Also, the desire among many climate change scientists to portray unanimity may enhance the perceived seriousness of the potential consequences of climate catastrophes, but paradoxically undermine their credibility in doing so. We explore strategies for communicating extreme forecasts that are mindful of these results.