Rising Global Elderly Health Inequalities in the Face of Temperature Extremes

The elderly population, being particularly vulnerable, is expected to face increased life-threatening risk due to climate change, especially in low-income regions, thereby exacerbating global inequalities. Here we developed the Elderly Mortality Risk Index (EMRI) to sufficiently understand the intricate relationships among aging, climate vulnerability, and elderly health risk from temperature extremes. Our analysis shows that the cumulative intensity and duration of global temperature extremes has increased by an average of 36% from 1990 to 2020 and is projected to rise by 52% over the next 30 years. The Global South, inhabited by 10% of the world's elderly (aged 69+), bears 53% of the EMRI during the 60-year period. Low-income regions experience the highest EMRI, averaging 4% more than other regions. Projections for 2021–2050 indicate that the global EMRI will peak in 2033 before gradually declining. South Asia (SA) and Southeast Asia are expected to be the most severely affected regions, with averaged EMRI 8% higher than those in the lowest-risk regions. When focusing on age-specific groups (69+), the global EMRI will be 59% higher, the EMRI disparity is projected to be 13 times greater between SA and the lowest-risk regions, and 80 times greater between high-income and low-income regions, than when considering all-age group. Our findings highlight the urgent need for targeted climate adaptation strategies and enhanced gerontological support to address the growing health challenges in an aging and warming world.