Mashable: The Chinese government issued the second-ever "red alert" for deadly air pollution in the capital city of Beijing on Friday, putting the city's 22.5 million people on notice that the air contains an unhealthy amount of pollution. The alert triggered sharp restrictions on vehicle traffic, with half of the city's cars forced off the road each day, and forced authorities to close city schools.
The alert is the second red alert in one week. Prior to December 8, no red alert had ever been issued for...