The left image shows atmospheric visibility dropped sharply during a severe haze event in Beijing. The right image shows an increase in the frequency of conducive weather conditions (represented by the HWI) under future high greenhouse emission scenario (RCP8.5)(2050-2099) relative to the historical climate (1950-1999). Special thanks to Prof. ZHU Jiang for providing the left photo which is featured as the cover of Nature Climate Change April 2017 issue. Credit IAP