An integrated assessment of provincial economic damages from climate change in China.

Quantifying sub-national climate damages is essential for guiding localized climate policies and adaptation strategies. However, few studies have developed assessment frameworks that capture intra-regional variations, sectoral interactions, and multiple damage channels, especially for China. This study constructs an integrated assessment framework by combining earth system models with a provincial computable general equilibrium model (the China Regional Energy Model), incorporating three key damage modules: labor productivity, household energy demand, and agricultural productivity. Results show that climate damages are projected to account for 3.6% (2.2% to 4.7%) and 4.3% (3.5% to 5.7%) of China's GDP in 2060 under shared socioeconomic pathway (SSP) 1-2.6 and SSP2-4.5, respectively. Regional analysis reveals a notable north-south divide, with the most severe losses concentrated in southern and central provinces. General equilibrium impacts are approximately 136% of the accounting-based impacts, with significant variations across damage channels and regions, highlighting heterogeneous spillover effects driven by sectoral linkages and regional disparities. Cost-benefit analysis suggests that around 57% (-14% to 112%) of mitigation costs for transitioning from SSP2-4.5 to SSP1-2.6 in 2060 could be offset by avoided climate damages around this period, with the northwest and northeast regions experiencing the largest net benefit rates. This study provides an interdisciplinary perspective on the patterns of climate change impacts in China and offers a scientific basis for improving local climate policies and adaptation strategies.