Where does scientific uncertainty come from, and from whom? Mapping perspectives of natural hazards science advice

The science associated with assessing natural hazard phenomena and the risks they pose contains many layers of complex and interacting elements, resulting in diverse sources of uncertainty. This creates a challenge for effective communication, which must consider how people perceive that uncertainty. Thus, we conducted twenty-five mental model interviews in Aotearoa New Zealand with participants ranging from scientists to policy writers and emergency managers, and through to the public. The interviews included three phases: an initial elicitation of free thoughts about uncertainty, a mental model mapping activity, and a semi-structured interview protocol to explore further questions about scientific processes and their personal philosophy of science. Qualitative analysis led to the construction of key themes, including: (a) understanding that, in addition to data sources, the ‘actors’ involved can also be sources of uncertainty; (b) acknowledging that factors such as governance and funding decisions partly determine uncertainty; (c) the influence of assumptions about expected human behaviours contributing to “known unknowns'; and (d) the difficulty of defining what uncertainty actually is. Participants additionally highlighted the positive role of uncertainty for promoting debate and as a catalyst for further inquiry. They also demonstrated a level of comfort with uncertainty and advocated for ‘sitting with uncertainty’ for transparent reporting in advice. Additional influences included: an individual's understanding of societal factors; the role of emotions; using outcomes as a scaffold for interpretation; and the complex and noisy communications landscape. Each of these require further investigation to enhance the communication of scientific uncertainty.