In China, cloud-free days mean smog, not sun
China has darkened over the past half-century. Where has all the sunshine gone? The usual suspect, at least to a climatologist, would be cloud cover. But in the most comprehensive study to date of overcast versus cloud-free days in China, a team led by the Department of Energy’s Pacific Northwest National Laboratory, reporting in the current advance online issue of Geophysical Research Letters, has found that cloud cover has been decreasing for the past 50 years.