Projection of heat wave mortality related to climate change in Korea

Heat waves associated with climate change are a significant future concern. Although deaths from heat disorders are a direct effect of heat wave incidences, only a few studies have addressed the causal factors between heat wave incidences and deaths from heat disorder. This study applies regression analysis to the time series data in order to deduce the causal factors that affect the number of deaths from heat disorders (NDHD) in Korea using observational dataset from 1994-2012. The duration of a heat wave and the age of the population are highly correlated with the magnitude of the NDHD. Based on this correlation we also analyze heat wave projections to the climate change scenarios produced using the Hadley Centre Global Environmental Model version 3 under the Representative Concentration Pathways (RCP 4.5 and RCP 8.5) and to the single aging population scenario till 2060. The magnitude of the NDHD is expected to elevate by approximately fivefold under the RCP4.5 and 7.2-fold under the RCP 8.5 scenarios compared to the current baseline value (a parts per thousand 23 people per summer). Of greater concern is that the steady death rate increase is expected to be intercepted by the more severe events in future compared to the present period. Under both RCP scenarios considered, the extreme cases are projected to eventuate around the 2050s with approximately 250 deaths. We find that in spite of the greenhouse gas policy proposed to meet reductions under the RCP 4.5 scenario; serious heat wave damage in terms of human mortality may still be unavoidable in Korea.