Unraveling the global economic and mortality effects of rising urban heat island intensity

The increasing severity of urban heat island (UHI) effects poses a significant concern in cities, where to over half of the world's population lives. We examine the pattern of surface UHI intensity (SUHII) and its effect on urban economic productivity and mortality across 171 countries from 2003 to 2018. Countries with heavy industrial/ manufacturing bases and higher income levels face more significant economic repercussions from SUHII. Males experience higher mortality rates under comparable SUHII conditions. A unit increase in GNI correlates to a 23.2 % rise in SUHII's effect on GDP and a 5.5 % increase in its effect on mortality rate. A higher Socio-Demographic Index mitigates SUHII's impact on urban GDP. Moreover, the Gini index directly impacts SUHII more than it affects SUHII-related mortality through inequality. Reducing income inequality by one unit will increase the enhancing effect of SUHII on the mortality rate by 11.8 %. Our findings reveal a significant link between wealth disparity and amplified health risks associated with SUHII, potentially leading to new forms of urban inequality. The study highlights the importance of development status and economic composition in facing UHI-related challenges and recommends equitable strategies for policymakers and urban planners to mitigate UHI effects in diverse developmental contexts.