Health and Economic Costs of Future Extreme Heat Risk

Evidence shows an ongoing increase in the frequency and severity of global heatwaves, raising concerns about the future impacts of climate change and the associated socio-economic costs. Here, we develop a disaster footprint analytical framework by integrating climate models, epidemiological and hybrid input-output, and computable general equilibrium global trade models to estimate the mid-century socioeconomic impacts of heat stress. We consider health costs related to heat exposure, the value of heat-induced labor productivity loss, and indirect losses due to economic disruptions cascading through supply chains. We find that the global heatwave days would increase by 104% in 2060 compared to 2022 under SSP585, and the global average annual number of heat-induced deaths would increase to around 1.12 million (0.85 ~ 1.39 million). For economic impacts, we show that the global annual incremental loss increases exponentially from 0.03±0.01 (SSP245) ~ 0.05±0.03 (SSP585) percentage points during 2030 – 2040 to 0.05±0.01 ~ 0.15±0.04 percentage points during 2050 – 2060. By 2060, the expected global economic losses reach a total of 0.6% ~ 4.6% with losses attributed to health loss (37%~45%), labor productivity loss (18%~37%), and indirect loss (12%~43%) under different SSPs. Small and medium-sized developing countries in Southeast Asia and Africa suffer the most from heat risks as well as regional supply chain disruptions.