Projections of temperature-related cause-specific mortality under climate change scenarios in a coastal city of China

Abstract

BackgroundNumerous studies have been conducted to project temperature-related mortality under climate change scenarios. However, most of the previous evidence has been limited to the total or non-accidental mortality, resulting in insufficient knowledge on the influence of climate change on different types of disease. ObjectivesWe aimed to project future temperature impact on mortality from 16 causes under multiple climate change models in a coastal city of China. MethodsWe first estimated the baseline exposure-response relationships between daily average temperature and cause-specific mortality during 2009–2018. Then, we acquired downscaled future temperature projections from 28 general circulation models (GCMs) under two Representative Concentration Pathway (RCP4.5 and RCP8.5). Finally, we combined these exposure-response associations with projected temperature to estimate the change in the temperature-related death burden in different future decades in comparison to the 2010 s, assuming no demographic changes and population acclimatization. ResultsWe found a consistently decreasing trend in cold-related mortality but a steep rise in heat-related mortality among 16 causes under climate change scenarios. Compared with the 2010 s, the net change in the fraction of total mortality attributable to temperature are projected to −0.54% (95% eCI: −1.69% to 0.71%) and −0.38% (95% eCI: −2.73% to 2.12%) at the end of the 21st century under RCP4.5 and RCP8.5, respectively. However, the magnitude of future cold and heat effects varied by different causes of death. A net reduction of future temperature-related death burden was observed among 10 out of 15 causes, with estimates ranging from −5.02% (95% eCI: −17.42% to 2.50%) in mental disorders to −1.01% (95% eCI: −5.56% to 3.28%) in chronic lower respiratory disease. Conversely, the rest diseases are projected to experience a potential net increase of temperature-related death burden, with estimates ranging from 0.44% (95% eCI: −4.40% to 6.02%) in ischemic heart disease and 4.80% (95% eCI: −0.04% to 9.84%) in external causes. ConclusionsOur study indicates that the mortality burden of climate change varied greatly by the mortality categories. Further investigations are warranted to comprehensively understand the impacts of climate change on different types of disease across various regions.