Increasing probability of record-population exposure to high temperature and related health-risks in China

• Published in: Environmental research 2023-08, Vol.231 (Pt 2), p.116176-116176, Article 116176
• Main Authors: Zhang, Haiyan, Sun, Meiping, Yao, Xiaojun, Xie, Zhenyu, Zhang, Mingjun
• Format: Article
• Language: English
• Subjects: China; Health risk; High temperature; Population exposure; Projection
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2023.116176

Combining the comprehensive effects of temperature and humidity, this study applies a heat stress index to project future population exposure to high temperature and related health-risks over China under different climate change scenarios. Results show that the number of high temperature days, population exposure and their related health-risks will increase significantly in the future compared to the reference period (1985–2014), which is mainly caused by the change of >T99p (the wet bulb globe temperature >99th percentile derived from the reference period). The population effect is absolutely dominant in influencing the decrease in exposure to T90-95p (the wet bulb globe temperature is in the range of (90th, 95th]) and T95-99p (the wet bulb globe temperature is in the range of (95th, 99th]), and the climate effect is the most prominent contributor to the upsurge in exposure to > T99p in most areas. An additional 0.1 billion person-days increase in population exposure to T90-95p, T95-99p and >T99p in a given year is associated with the number of deaths by 1002 (95% CI: 570–1434), 2926 (95% CI: 1783–4069) and 2635 (95% CI: 1345–3925), respectively. Compared with the reference period, total exposure to high temperature under the SSP2-4.5 (SSP5-8.5) scenario will increase to 1.92 (2.01) times in the near-term (2021–2050) and 2.16 (2.35) times in the long-term (2071–2100), which will increase the number of people at heat risk by 1.2266 (95% CI: 0.6341–1.8192) [1.3575 (95% CI: 0.6926–2.0223)] and 1.5885 (95% CI: 0.7869–2.3902) [1.8901 (95% CI:0.9230–2.8572)] million, respectively. Significant geographic variations exist in the changes of exposure and related health-risks. The change is greatest in the southwest and south, whereas it is relatively small in the northeast and north. The findings provide several theoretical references for climate change adaptation. •Exposure to high temperature-related deaths increase by 1.2266–1.3575 (1.5885–1.8901) million in 2021–2050 (2071–2100) compared to 1985–2014.•Future increases in exposure to high temperature and related health risks are mainly caused by the upsurge in extreme heat.•The southwest and south with higher population exposure to high temperature experience higher health risks.