Surging Economic Losses From Extreme Floods Exacerbate Disparity in Poverty‐Classified Regions Demanding Urgent Adaptation in China

Abstract

Extreme floods rank among the most destructive natural hazards, disrupting economic development, societal stability, and river ecosystems. Although macro‐scale flood risk disparities across poverty‐classified regions have drawn increasing attention, they remain critically underexplored in China, the world's most flood‐vulnerable country, where flood‐induced human displacement accounts for one‐third of the global total. Here, we develop a rigorously validated, macro‐scale framework to estimate flood‐induced economic losses across China and to quantify the disparity of these impacts across distinct poverty strata. We find that impoverished regions experience disproportionately severe relative impacts, with their flood losses escalating by at least 22% for each 0.5°C of global warming, outpacing non‐poor regions by up to seven percentage points. Furthermore, economic growth within projected flood‐prone areas markedly exacerbates these losses. Although enhancing flood‐defense standards can mitigate damages, maintaining historical loss levels requires ambitious defense standard upgrades of 80% (under 1.5°C of warming) and 95% (under 2.0°C), corresponding to an average 16‐percentage‐point improvement per 0.5°C of warming. Our findings reveal the accelerating flood risk and macro‐scale disparity faced by impoverished regions in China, a dynamic long overlooked, and challenge the adequacy of historical flood risk management strategies. As nations work toward the United Nations Sustainable Development Goals (SDGs), particularly SDG 10 (Reduced Inequalities), which intrinsically requires a foundational understanding of risk disparities, our study provides critical baseline evidence for national adaptation planning and offers globally transferable methodologies.