This is how blue the skies were when Beijing banned 2.5 million cars for 2 weeks (and how it’s gone in 24 hrs) http://boingboing.net/2015/09/04/this-is-how-blue-the-skies-wer.html
This is how blue the skies were when Beijing banned 2.5 million cars for 2 weeks (and how it’s gone in 24 hrs) http://boingboing.net/2015/09/04/this-is-how-blue-the-skies-wer.html