Everyday adaptation to summer heatwaves: A global perspective

Unprecedented heatwaves have become characteristic of summers worldwide, with devastating impacts on people’s health, well-being, and livelihoods. In light of this urgent threat, government institutions across the globe are developing guidelines and planned interventions to increase resilience to heatwaves – measures which require an understanding of how people adapt to extreme heat within the constraints of daily life. Existing studies have used large-scale mobility data to characterize heatwave adaptation at a population-level, though these studies skew towards cities and regions in high-income countries, have diverse methodologies which limit generalizability to other contexts, and focus on ‘activity level’ changes without discerning which activities are being altered. Addressing these gaps, this study combines ERA5 climate re-analysis, cell phone mobility, and socio-economic data across Brazil, China, France, India, Nigeria, Turkey, and the USA during 2022 heatwaves. For the first six countries, Google Community Mobility Reports data is used in multi-level modeling to explore changes to various everyday activities during heatwaves (home, work, transit, grocery/pharmacy, retail/recreation, parks). In China, Baidu data on intra-city activity levels is analyzed in a complementary multi-level model. Strong patterns of withdrawal towards the home occur during heatwaves, varying with climatic, temporal, and contextual factors. These common patterns result from diverse activity substitutions across countries and simultaneously occur alongside changes towards other non-home activities. This internationally comparative study highlights the global nature of heatwave adaptation, the importance of context-specific adaptive responses, and the value of considering heatwave adaptation through the lens of people’s everyday activities.