Rising temperatures, rising disparities: The future of heat exposure in the U.S. by 2050

Abstract

Future global warming will affect nearly every aspect of human society and daily life. Yet, little is known about disparities in exposure to future heatwaves across different social groups. This study provides a fine-grained, spatially explicit prediction of heat-affected populations in the continental United States by 2050, considering four combined scenarios of shared socioeconomic pathways and representative concentration pathways. Incorporating projected changes in socio-demographic and economic compositions, we find that global warming is likely to exacerbate disparities in heat exposure, as measured by the Gini coefficient. The poverty group, residing in 52 % of continental states, is projected to face the greatest impact, followed by Black and Asian populations. Additionally, residents of densely populated metropolitan areas are expected to experience greater inequalities in heat exposure compared to those in smaller metropolitan regions. These findings underscore the regions where heat interventions are most urgently needed and emphasize the importance of prioritizing social equity—aligning with the United Nations’ Sustainable Development Goals and their guiding principle of leaving no one behind.