Role of adaptation measures in addressing heatwave exposure in China

Heatwave exposure has increased dramatically because of climate warming and population growth, along with their interactive effects. However, effective adaptation measures can reduce these impacts. Nonetheless, the dynamic changes, regional inequality in adaptive capacity and their potential contributions to reducing exposure in the future remain unclear. This study quantifies the impact of adaptive capacity and underscores regional variations in heatwave magnitudes, population exposure and adaptation levels in China. We projected the future adaptive capacity using air-conditioner penetration, factoring in climate cooling requirements and individuals’ purchasing power. Utilising population and gross domestic product (GDP) data from four Shared Socioeconomic Pathways (SSP1, SSP2, SSP3 and SSP5) and daily temperature data from four SSP-based emission scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5), we estimated heatwave duration, population exposure and avoided impacts through adaptation across China and its sub-regions. Results show a substantial increase in heatwave duration in Southwest and Southern China, especially under the SSP5-8.5 scenario, with a projection of 163.2 ± 36.7 d during 2081–2100. Under the SSP3|SSP3-7.0 scenario, total exposure reaches 156.4 ± 76.8 billion person d per year, which is the highest among all scenarios and 23 times greater than that in 1986–2005 without adaptation. Upon considering adaptation measures, a noteworthy reduction in population exposure is observed, especially in the SSP3|SSP3-7.0 and SSP5|SSP5-8.5 scenarios, with reductions of (62.6 ± 3.9) % and (65.8 ± 5.1) %, respectively, compared with the scenario without adaptation during 2081–2100. Remarkable regional disparities in avoided impacts are also evident, with variations of up to 50% across different regions. The implementation of effective and environmentally friendly adaptation measures can notably address climate change, thereby alleviating the profound threats posed to human well-being.