Risk communication and public policy decision-making for extreme events: a personal reflection

Assessing the risks from extreme events, and deciding on the appropriate measures to ameliorate these risks, may be challenging for many policymakers who are unfamiliar with quantitative measures of risk. There is a need for risks to be expressed in terms understandable to policy makers and the public. An illustrative case study is a risk assessment of 14 fig trees from an iconic street in Newcastle where their safety risks were judged too high because an arborist consultant calculated that the risk of harm was 1 in 19.8 per tree per year – so walking down that street was 400 times more dangerous than driving a car! Other examples relate to terrorism and climate change. There is often an inability of the community and public officials to understand the notion of risk and probabilities. The paper will describe how decision metrics often involve probabilistic thinking by public officials, and how best to communicate this type of information in a manner more easily understood by the community and public officials.