Risk tolerance and climate change adaptation: A need for transparency in policy assumptions and implications

To inform policy priorities, climate change risk assessments are often framed through an adaptation gap between current planned actions and those required to manage risk effectively. Residual risks remain to be managed through autonomous and reactive responses. Adaptation policies therefore assume a level of risk tolerance, but this is usually not made explicit. This lack of transparency can lead to a mismatch in expectations, especially when risk is increasing or perceived differently from experts. It also constrains wider engagement in adaptation decisions. These issues are explored both conceptually and through a UK case study referencing the third National Adaptation Programme whose generalised objectives demonstrate a policy delivery paradox that has also been subject to legal challenge. The paradox is exemplified by top-down objectives for resilience building or risk reduction that are ambiguous on assumed risk tolerance thresholds and implications for managing residual risks across all of society. A case is therefore made that both risk assessments and policy frameworks need explicit declarations on assumed risk tolerance and its implications, especially regarding those bearing the risks. This openness would be consistent with calls for an ‘honest conversation’ on expectations and viability of risk management outcomes between policy, stakeholders and public. Deliberation may involve difficult normative issues, especially to reconcile increasing risks against current resource constraint challenges. But it is ultimately necessary for wider societal adaptation engagement and increased adaptive capacity, including aspirations for enhanced collective resilience. Recommendations are hence provided to better explicate risk tolerance distinctions in adaptation research and policy.