Detection and projection of climatic comfort changes in China's mainland in a warming world

Climatic comfort,which refers to the comfort of the human body's thermal sensations,is important for the human habitat.Although considerable efforts have been provided to examine changes in climatic comfort response to global warming from a partial perspective,the trajectory shift in past and future climatic comfort conditions in China's mainland based on uniform indicators has not been revealed.The spatiotemporal pattern of climatic comfort over historical and future periods was investigated in this study,using China's mainland as an example.The temperature-humidity index was adopted on the basis of homogenised meteorological station observations and high-resolution climate model simulations to analyse the trends of comfort/discomfort days from 1960 to 2017 and project changes in climatic comfort under representative concentration pathway scenarios in the late 21st century(2071-2100).Results show a substantial decrease in colduncomfortable days and a moderate increase in comfortable and warm-uncomfortable days from 1960 to 2017.In the late 21st century,the signals of increasing warm-uncomfortable and decreasing cold-uncomfortable days are projected to enhance significantly while the direction of changes in comfortable days exhibits a north-south divergence.The uneven changes in warm-and cold-uncomfortable days and an overall decrease in comfortable days in the late 21st century dominate the future trends in climatic comfort in the densely populated southeast half of China.Effective measures taken for adapting to and mitigating global climate warming can considerably avoid the adverse impact of the projected change.