Investigation on the Heat Effect of Climate Change on Years of Life Lost in Guangzhou

Objectives  To investigate heat-related years of life lost of Guangzhou residents under different climate change scenarios, and to assess the increase of adaptation in residents to the impact of heat effect.

Methods  The historical data on climate change in Guangzhou from 2011 to 2013 were collected and a Distributed Lag Non-linear Model (DLNM) was used to estimate the association between daily mean temperature (TM) and daily YLLs. Employing two sets of daily temperature for the 1980s (baseline), 2030 s, 2060 s and 2090 s derived from a Chinese Regional Climate Model (RegCM4.0) under RCP 4.5 and 8.5 scenarios to estimate the baseline and future excess heat-related YLLs attributable to ambient temperature; and to estimating also the excess heat-related YLLs in the future after taking into account the adaptation of people.

Results  Assuming no change in adaptation and population size, a significant increase in excess heat-related YLLs in the 21^st century under both climate change scenarios could be estimated. Compared with the 1980s, the annual excess YLLs in total population for the 2090s under RCP 4.5 and 8.5 scenarios were 9.285.0 and 24.549.0 respectively. However, improving adaptive capacity of people (increase in 4.6% per decade) could largely offset the future heat-related YLLs, no matter which scenario of climate was changed and how many population was increased. For instance, under a RCP8.5 scenario, increasing the adaptation in people during the 2030s, 2060s and 2090s scenario, heat effect could be offset by 54%, 70% and 72%, respectively.

Conclusions  Projected changes in climate are likely to lead to an increase of heat-related YLLs in Guangzhou in this century. The risk would be more pronounced in high-emission scenarios. The heat effect could be largely offset by improving the adaptive capacity of people in the future. Enhancing health protection from heat stress would be necessary in China.