Deciphering the unequal impact of extreme temperatures on county sustainability in China

This study investigates the nonlinear effects of extreme temperatures on county-level sustainable development in China, addressing a critical gap in climate change impact research. Understanding this relationship is crucial for developing effective climate adaptation and mitigation strategies at the local level. China’s vast territory and diverse climate conditions are utilized as a natural experiment, given its position as the world’s largest developing economy and greenhouse gas emitter. We construct a novel county sustainability index encompassing five dimensions: human capital, natural capital, physical capital, financial capital, and social capital. Using panel data from 2000 to 2020 and a fixed effects model, we estimate the effect of temperature bins on sustainability. An inverted U-shaped relationship between temperature and sustainability is identified, with an optimal range between 6 and 12 °C. Agricultural counties show greater vulnerability to extreme heat, while non-agricultural counties are more affected by extreme cold. We identify agricultural mechanization, grain production, and labor productivity as key transmission channels. Our research contributes to understanding the complex climate-sustainability relationship, highlighting Chinese counties’ differential vulnerability to climate change. Evidence is provided for the development of targeted policies to mitigate the adverse impacts of extreme temperatures on sustainable development.