Progressive climate change and disasters: communicating uncertainty

Communication of uncertainty gained prominence from risk communication work starting in (at latest) the 1980s and has increasingly become salient with a growing need to communicate uncertainty of climate change impacts (USPHS 1995; Nerlich et al. 2010). Nonetheless, ignorance, apathy and blaming persist in many sectors, from the general public to specialist scientists, indicating various (mis)understandings of and responses to uncertainty. The reasons are complicated, but some can be understood by addressing what, why, whom, how and when uncertainty is communicated. A major dilemma of communicating uncertainty is that it is more about certainty (Sandman and Lanard 2011). Failure of uncertainty communication or its misunderstanding may lead to loss of trust, a poor reputation and inadequate response (Sandman and Lanard 2011). One common misinterpretation of hazard uncertainty is that a ‘‘100-year flood’’ will not happen soon after its recent occurrence. That can reduce public preparedness, and subsequently, a repeated occurrence of such flood could lead to further asset losses along with loss of trust in risk communication. A few important dimensions to consider in communicating uncertainty are information on its (1) source, (2) scale and (3) complexity. While it may seem obvious to communicate the source of uncertainty, it does not always happen. Disasters such as fires, floods, and droughts—even earthquakes and tsunami!—are misattributed to climate change (Sarewitz and Pielke 2005). Frequently, the causes of hazards and disasters are portrayed to be external to the human domain, discounting human actions and vulnerability. For example, floods are often communicated to be caused by heavy rain or snowmelt without accounting for the role of human activities changing river morphology and local vulnerability, despite repeatedly being pointed out in the literature.