An analysis of the bioclimates in different climates and implications for the built environment in China

Underlying trends of long-term summer and winter discomfort in terms of heat and cold stresses in the nine major thermal climate zones and sub-zones across China were investigated using 102-year (1901–2002) weather data. In severe cold climates, winter discomfort dominated (about 66%) and the comfort index (CI) varied from −5 (extremely cold) to +2 (hot). A gradual shift from predominantly negative CI to positive CI was observed as one moved across the climate zones from the north to warmer climates in the south. Temperature rise resulted in less discomfort in the winter and more discomfort in the summer. Though the reduction in cold stress and increase in heat stress were moderate during the 102-year period, the last two decades tended to exhibit the largest changes. It is envisaged that if these trends continue, changes in cold and heat stresses in the 21st century would be much greater than those experienced during the 20th century. This could have significant implications for building designs and energy use in the built environment.