The air in Chinese cities is getting worse, and these animations show just how severe the problem has become.
When a ranking Chinese government official slammed the U.S. embassy and consulates in China earlier this month for measuring local air pollution data, calling it "violating diplomatic conventions," Chinese web users snapped back. "Can't you see the bad pollution yourself?" asked one typical comment.
China's censors have tremendous power in print, online, and even in public spaces such as Tiananmen Square. But when it comes to air pollution, even the Chinese government can't obscure the facts. People see and breathe it every day.
The debate over whose statistics are most "accurate" can be confusing -- how to sort out truth from spin? That's why a group of us at the Asia Society decided to launch China Air Daily, a website that provides up-to-date information on air pollution in the country's largest urban sectors, and even compares them to major cities from elsewhere in the world.
According to a 2007 report produced by the World Bank and Chinese government, up to 400,000 Chinese die prematurely every year because of air pollution. The concentration of particles in the air that are smaller than 2.5 micrometers, the size at which they can penetrate the lungs, is on average 10 times higher in Beijing than in New York, according to our past three months of data collection. But such figures alone don't tell the story. A set images at the top of this page show Beijing on a clear day versus a smoggy; move the slider back and forth with your mouse and you might start to understand the extent to which pollution affects Chinese cities such as Beijing.