Projecting impacts of temperature and population changes on respiratory disease mortality in Yancheng

Respiratory diseases cause significant morbidity and mortality, especially in developing countries. Recently, the influence of global warming on respiratory disease mortality has become a growing concern in research. Data on respiratory disease mortality, meteorological elements and air pollutants during 2014-2017 were collected from Yancheng in China. We applied the distributed lag non-linear model (DLNM) and performed a quasi-Poisson distribution fitting to evaluate the baseline relationship between the mean temperature and total respiratory diseases mortality, and then projected the future changes of total respiratory diseases mortality without adaptation and with adaptation in Yancheng during three future periods under two Representative Concentration Pathways (RCP) scenarios(RCP4.5 and RCP8.5) and three population scenarios including one constant and two Shared Socio-economic Pathways (SSP) scenarios (55P2 and 55P5). Under four combination scenarios, future warming causes additional heat-related mortality but reduced cold-related mortality in Yancheng from the 2030s to the 2070s. Under SSP population scenarios, the reduced numbers of cold-related deaths offsetting the additional numbers of heat-related deaths lead to the decreases in net temperature-related mortality in the 2050s and 2070s. Future population change has more influence on respiratory mortality than future climate change scenarios does. When the adaptation was adpoted, the heat-related mortality risks and the net temperature-related mortality risks become smaller, but the cold-related mortality risks become larger than that without adaptation.