Applications of Risk Assessment in the Development of Climate Change Adaptation Policy

The consequences of climate change will affect both natural systems and human populations. Adaptation policies that provide mitigation against these effects require the collaboration of natural and socio-economic sciences to assess future risks of climate change. Future impacts and the vulnerability of the impacted system are used to perform risk assessments allowing decision-makers to select optimal adaptation choices given available knowledge. Under climate change, however, future risk assessments are based on a number of possible climate scenarios. This multiplicity results in more than one assessment of risk with large uncertainty bounds. Present applications of risk assessment for climate change adaptation have taken two main approaches. The main difference between these approaches is in the presentation of the final risk either as cumulative probability distributions of threshold exceedance or as a number of risk assessments assigned to different plausible futures. Different adaptation scenarios or policies are then evaluated in terms of their effectiveness in reducing risk. This paper presents an analysis of applications of both approaches of risk assessment from recent literature for climatic effects such as sea-level rise. The analysis provides an evaluation of the strengths and weaknesses of present climate change risk assessment methods in terms of providing useful information to support decision-making at relevant spatial and temporal scales, and the ability of each method to direct policy-development by providing the best representation of future uncertainties given policy objectives. This analysis sheds light on the utility of climate change risk assessment methods as a function of information availability and policy scope, thereby providing the necessary factors that decision-makers should consider when a choosing an approach for adaptation policy development.