Human-perceived temperature changes over South China: Long-term trends and urbanization effects

Abstract

While the changes in air temperature under climate change and urbanization have been extensively examined in the literature, little is known about how human-perceived temperatures change. This study investigates the long-term changes in human-perceived temperatures (e.g., summer heat stress and winter wind chill conditions) over South China and quantifies the possible effects of urbanization. Daily observations at 86 stations during the period of 1961–2014 are collected and analyzed. Analysis results show that heat stress and wind chill temperature increase faster than air temperatures (i.e., daily mean, maximum, and minimum temperatures), and these increases are stronger in winter than in summer. The probabilities of hot extremes increase throughout the study period, whereas those of cold extremes decrease. Compared with those in non-urban areas, the warming trend in both seasons and the increase (decrease) in hot (cold) extremes are even more substantial in highly developed urban areas, such as the Pearl River Delta, indicating a remarkable effect of urbanization. It is estimated that urbanization contributes as much as half of the warming trend in summer and around one-third of the trend in winter. These results are helpful for mitigating climate change and reducing the impacts of extreme events.