Air pollution above a factory in Chengde, China
Levels of harmful air pollution over China have been falling steadily since 2015, due to stricter controls on emissions. China’s air is still terribly polluted, but the reduction has probably prevented 150,000 premature deaths per year.
“It’s probably the fastest any country has improved their air quality ever,” says Ben Silver at the University of Leeds in the UK. “But it’s still really bad.”
Silver and his colleagues tracked levels of tiny particles, called PM2.5, using data from over 1600 monitoring stations dotted around China. In line …