Beijing resident Zou Yi set out to illustrate the pollution problem in the city' by taking the same photo, at the same time each day, and creating a mosaic of the resulting images. The result is an unsettling mix of sunlit color and monochrome doomscapes.

"Like a lot of people," he said in an interview with CEN, "I forget [PM2.5] readings as soon as I read them. A picture is worth a thousand words. If you see the same place, at the same time over a full year, the quality of the air becomes perceptible immediately."

You can follow Zou on Weibo.