Department of Environmental Health, College of Public Health, East Tennessee State University, Johnson City, TN 37614, USA.
School of Environment and Natural Resources, Renmin University of China, Beijing 100872, China.
Environ Res. 2018 May;163:171-185. doi: 10.1016/j.envres.2018.01.047. Epub 2018 Feb 22.
Global climate change is anticipated to raise overall temperatures and has the potential to increase future mortality attributable to heat. Urban areas are particularly vulnerable to heat because of high concentrations of susceptible people. As the world's largest developing country, China has experienced noticeable changes in climate, partially evidenced by frequent occurrence of extreme heat in urban areas, which could expose millions of residents to summer heat stress that may result in increased health risk, including mortality. While there is a growing literature on future impacts of extreme temperatures on public health, projecting changes in future health outcomes associated with climate warming remains challenging and underexplored, particularly in developing countries. This is an exploratory study aimed at projecting future heat-related mortality risk in major urban areas in China. We focus on the 51 largest Chinese cities that include about one third of the total population in China, and project the potential changes in heat-related mortality based on 19 different global-scale climate models and three Representative Concentration Pathways (RCPs). City-specific risk estimates for high temperature and all-cause mortality were used to estimate annual heat-related mortality over two future twenty-year time periods. We estimated that for the 20-year period in Mid-21st century (2041-2060) relative to 1970-2000, incidence of excess heat-related mortality in the 51 cities to be approximately 37,800 (95% CI: 31,300-43,500), 31,700 (95% CI: 26,200-36,600) and 25,800 (95% CI: 21,300-29,800) deaths per year under RCP8.5, RCP4.5 and RCP2.6, respectively. Slowing climate change through the most stringent emission control scenario RCP2.6, relative to RCP8.5, was estimated to avoid 12,900 (95% CI: 10,800-14,800) deaths per year in the 51 cities in the 2050s, and 35,100 (95% CI: 29,200-40,100) deaths per year in the 2070s. The highest mortality risk is primarily in cities located in the North, East and Central regions of China. Population adaptation to heat is likely to reduce excess heat mortality, but the extent of adaptation is still unclear. Future heat mortality risk attributable to exposure to elevated warm season temperature is likely to be considerable in China's urban centers, with substantial geographic variations. Climate mitigation and heat risk management are needed to reduce such risk and produce substantial public health benefits.
全球气候变化预计将导致整体气温上升，并有可能增加未来因热导致的死亡率。由于易感人群高度集中，城市地区尤其容易受到高温的影响。作为世界上最大的发展中国家，中国经历了明显的气候变化，部分证据是城市地区频繁出现极端高温，这可能使数百万居民面临夏季热应激，从而增加健康风险，包括死亡率。虽然有越来越多的文献研究未来极端温度对公共健康的影响，但预测与气候变暖相关的未来健康结果的变化仍然具有挑战性和研究不足，特别是在发展中国家。这是一项探索性研究，旨在预测中国主要城市未来与热相关的死亡风险。我们关注的是中国 51 个最大的城市，这些城市约占中国总人口的三分之一，并根据 19 个不同的全球规模气候模型和 3 个代表性浓度路径（RCP）预测与热相关的死亡风险的潜在变化。使用特定城市的高温和全因死亡率风险估计值来估算未来两个 20 年期间的年度与热相关的死亡人数。我们估计，在 21 世纪中叶（2041-2060 年）相对于 1970-2000 年，51 个城市的过量热相关死亡人数将约为 37800（95%CI：31300-43500）、31700（95%CI：26200-36600）和 25800（95%CI：21300-29800）每年 RCP8.5、RCP4.5 和 RCP2.6 下的死亡人数。与 RCP8.5 相比，通过最严格的排放控制情景 RCP2.6 减缓气候变化，预计将避免 51 个城市在 50 年代每年 12900（95%CI：10800-14800）和 70 年代每年 35100（95%CI：29200-40100）的死亡人数。人口对热的适应可能会降低过量热死亡率，但适应程度仍不清楚。中国城市中心因暴露于升高的暖季温度而导致的未来热死亡率风险可能相当大，且存在显著的地域差异。需要采取气候缓解和热风险管理措施来降低这种风险，并带来重大的公共健康效益。
