A risk-risk trade-off assessment of climate-induced mortality risk changes

The impact of climate change on human health was identified as a priority for the UN COP26 conference. In this article, we consider climate-induced changes to mortality risks and how to incorporate these formally in the policy appraisal process. In the United Kingdom (UK), the Value of Statistical Life (VSL) is used to monetarize the benefits of policies to reduce mortality risks but it remains an open, empirical question as to whether the current VSL (£2.14 million per fatality prevented, December 2021 values) for traffic accidents should be applied in other contexts without any modification and particularly for extreme weather event fatalities. Using a representative sample of the UK population, we aim to estimate and better understand the trade-offs people make when comparing mortality risks, drawing on psychological insights from construal level and regulatory focus theories. We design a stated preference survey using a relative valuation framework with nonmonetary, risk-risk trade-off questions between extreme weather event and traffic accident mortality risks. We find evidence of an extreme weather event risk premium of 1.2-1.6 (implying a climate-related VSL of £2.52-£3.41 million). We also find that participants who are psychologically close to climate change (based on construal level theory), weigh reducing extreme weather event mortality risks almost two times that of reducing traffic accident mortality risks.