Acta Geographica Sinica ›› 2016, Vol. 71 ›› Issue (7): 1189-1200.doi: 10.11821/dlxb201607008

• Ecology and Environment • Previous Articles     Next Articles

Changes in population exposure to high temperature under a future scenario in China and its influencing factors

Dapeng HUANG1,2(), Lei ZHANG3, Ge GAO1,2   

  1. 1. National Climate Center, China Meteorological Administration, Beijing 100081, China
    2. Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing 210044, China
    3. National Meteorological Center, China Meteorological Administration, Beijing 100081, China
  • Received:2015-10-25 Revised:2016-05-25 Online:2016-07-25 Published:2016-07-27
  • Supported by:
    National Natural Science Foundation of China, No.41101517

Abstract:

Population exposure to high temperature (extremely high temperature) is represented by the multiplication of the population in each grid cell and the projected mean annual number of hot days with daily maximum temperature above 35℃ (40℃) for each corresponding grid cell. Based on daily maximum temperature data from 21 global climate models under the RCP8.5 scenario and population projection data under the A2r socio-economic scenario, population exposures for four future periods (2021-2040, 2041-2060, 2060-2081 and 2081-2100) in China were projected at the grid cell level. The ensemble mean method was used to calculate the annual number of hot days. The relative importance of population and climate as drives of exposures was evaluated at the national level and the meteorological geographical division level. Compared with the population exposure for the 1981-2010 base period, population exposure to high temperature (≥ 35℃) over China for four future periods will increase by 1.3, 2.0, 3.6 and 5.9 times respectively and population exposure to extremely high temperature (≥ 40℃) will increase by 2.0, 8.3, 24.2 and 82.7 times respectively. Population exposure to high temperature will increase significantly in Jianghuai region, Southwest China and Jianghan region, especially in North China, Huanghuai region, South China, Jiangnan region. Population exposure to extremely high temperature will increase significantly in Southwest China and Jianghan region, especially in North China, Huanghuai region, Jiangnan region and Jianghuai region. Climate factors are the most important driver of exposures for Huanghuai region, Jianghuai region, Jianghan region, Jiangnan region, South China and Southwest China, followed by the interact effect of population and climate. At the national level, climate factor is also the most important driver, followed by the interact effect of population and climate. The contribution rate of climate to national-level projected change in exposure will decrease gradually from about 70% to about 60% and the contribution rate of concurrent changes in population and climate will increase gradually from about 20% to about 40% over the four future periods.

Key words: future scenario, population exposure, high temperature, extremely high temperature, influencing factors, China