The impact of environmental changes on the climate of China

Zhanquing Li


The climate of China has undergone significant changes over the past half a century when systematic measurements have been made. Of no doubt, causes for such changes are both natural and anthropogenic. For the sake of combating and migrating any adverse changes, it is imperative to understand and identify such causes. One prominent agent that could incur such changes is environmental degradation, especially air pollution that has shown general increasing trends. Aerosol particles can affect virtually all meteorological variables due to their direct and indirect effects on energy and water cycles. Heavy loading of aerosols reduce the amount of solar radiation reaching ground, that could lower surface temperature, reduce ocean-land contrast, whereas solar energy absorbed by aerosols alters atmospheric stability to have a feedback effect on atmospheric dynamics. By altering cloud microphysics and macrophysics, aerosols can also change cloud properties and precipitation frequency and amount. All of these can influence regional weather and climate in a dramatically. To tackle the problem and unravel various complex relations, data from both long-term routine measurements and intensive field experiments have been analyzed, together with some modeling studies, to tackle with the problems. Recent field experiments include the East Asian Study of Tropospheric Aerosols: an International Regional Experiment (EAST-AIRe), the East Asian Study of Tropospheric Aerosols and Impact on Regional Climate (EAST-AIRc), and Atmospheric Radiation Measurements (ARM) Mobile Facility mission in China (AMF-China). During these experiments, extensive measurements were made of aerosol optical, physical and chemical properties and a suite of radiation quantities. By means of data analysis and modeling, we found significant effects of aerosols on temperature, precipitation, fog and atmospheric circulation, attesting the significant roles of atmospheric environment on the regional climate and its changes in China.