Direct economic cost of future heat death estimates for India under climate change and population scenarios

Introduction: It is likely that the economic impacts of heat-related deaths will increase in the future. While several estimations of future heat-related deaths have been completed for the United States and other developed countries, there has been little success in achieving the same estimations for India. We estimate the direct costs of future heat related deaths in India over the next century by taking into account the contributions population and temperature make to such increases.

Methods: We calculated regression estimates of Exposure-Response (E-R) functions using temperature data from the World Bank’s climate data portal, historical heat-related death estimates from the Global Burden of Disease study, and population and mortality rate data from the UN population projections. We used our regression estimates to predict heat deaths under future climate change and population growth scenarios, and using the Value of Statistical Life (VSL) measures we calculated the associated direct economic costs.

Results: Future heat deaths are likely to increase across all climate change scenarios with approximately 84 thousand annual end century excess deaths under a business as usual (RCP 8.5) scenario and median population growth projection. These are associated with direct economic costs of approximately $23 billion using the VSL numbers for India. Using the US estimates just the direct economic costs are estimated to be half a trillion US dollars annually.

Discussion and Conclusion: Direct economic costs of heatwave deaths are likely to increase in the future under all climate change scenarios. While more data is needed to understand the relationship between increasing temperatures, human mortality, and their economic consequences our findings – as of the time of publication – provide the only comprehensive and long-term estimates for India.