Inequality in human development amplifies climate-related disaster risk

The severity of climate disaster impacts is shaped not only by the intensity of the events themselves but also by the exposure, vulnerability, and adaptive capac- ity of affected communities. The lack of globally comparable data integrating local societal and climatic conditions poses significant challenges to understand- ing which factors transform hazardous events into disasters. Existing research often neglects both hazard intensity and within-country inequality when analyz- ing the relationship between climate hazard events and their outcomes. Here, analyzing over 7,000 climate-related disasters from 1990 to 2020, we show that human development drives major shifts in global exposure and impact pat- terns, with societal vulnerability outweighing hazard intensity in driving impacts. Regions with low subnational Human Development Index (sHDI) scores expe- rience disproportionately higher human losses and economic damage, despite reduced hazard exposure over the past three decades. For instance, individuals in these regions are 8.2 times (95% CI: 2.16–23.06) more likely to be killed by storms compared to those in very high sHDI regions. Our findings also indicate that within-country inequality exacerbates disaster risk in low- and medium-sHDI regions. These results underscore the critical role of human development in miti- gating disaster risks and highlight the link between socioeconomic conditions and disaster vulnerability.