Projections of mortality attributable to hot ambient temperatures in Cyprus under moderate and extreme climate change scenarios

Background: Heat-related mortality has become a growing public health concern in light of climate change. However, few studies have quantified the climate-attributable health burden in Cyprus, a recognized climate change hotspot. This study aims to estimate the heat-related mortality in Cyprus for all future decades in the 21st century under moderate (SSP2-4.5) and extreme (SSP5-8.5) climate scenarios. Methods: We applied distributed lag non-linear models to estimate the baseline associations between temperature and mortality from 2004 to 2019 (data obtained from Department of Meteorology of the Ministry of Agriculture, Rural Development and Environment and the Health Monitoring Unit of the Cyprus Ministry of Health). The relationships were then extrapolated to future daily mean temperatures derived from downscaled global climate projections from General Circulation Models. Attributable number of deaths were calculated to determine the excess heat-related health burden compared to the baseline decade of 2000-2009 in the additive scale. The analysis process was repeated for all-cause, cardiovascular, and respiratory mortality and mortality among males, females, and adults younger or older than 65. We assumed a static population and demographic structure, no adaptation to hot temperatures over time, and did not evaluate potential interaction between temperature and humidity. Results: Compared to 2000-2009, heat-related total mortality is projected to increase by 2.7% (95% empirical confidence interval: 0.6, 4.0) and 4.75% (2.2, 7.1) by the end of the century in the moderate and extreme climate scenarios, respectively. Cardiovascular disease is expected to be an important cause of heat-related death with projected increases of 3.4% (0.7, 5.1) and 6% (2.6, 9.0) by the end of the century. Reducing carbon emission to the moderate scenario can help avoid 75% of the predicted increase in all-cause heat-related mortality by the end of the century relative to the extreme scenario. Conclusions: Our findings suggest that climate change mitigation and sustainable adaptation strategies are crucial to reduce the anticipated heat-attributable health burden, particularly in Cyprus, where adaptation strategies such as air conditioning is nearing capacity.