Extreme temperatures, mortality, and adaptation: Evidence from the county level in China

Area of Science:

• Environmental Health
• Epidemiology
• Climate Science

Background:

• Extreme temperatures pose significant health risks globally.
• Data on temperature-related mortality in developing nations is scarce.
• China's vast population and diverse climate make it a critical case study.

Purpose of the Study:

• To quantify the association between extreme temperatures and monthly mortality rates in China.
• To investigate the role of socioeconomic and infrastructural factors in moderating these effects.
• To project future mortality trends under climate change scenarios.

Main Methods:

• Utilized county-level data from 2872 regions in China.
• Employed statistical models to estimate the impact of daily maximum temperatures on monthly mortality.
• Accounted for potential harvesting effects (deaths occurring earlier than expected).

Main Results:

• An additional day with maximum temperatures ≥38°C increased monthly mortality by ~1.7% compared to 16-21°C.
• Higher GDP per capita correlated with reduced mortality impact from both hot and cold days.
• Improved housing quality mitigated heat-related mortality; better healthcare reduced cold-related mortality.

Conclusions:

• Extreme heat presents a substantial mortality risk in China, even after accounting for harvesting.
• Socioeconomic development and infrastructure improvements can attenuate temperature-related health burdens.
• Without adaptation, climate change is projected to increase annual mortality in many Chinese counties.