Does everyone remember the 2008 Beijing Olympics?  Prior to the games, Chinese authorities made a massive effort to clean up the smog and pollution plaguing Beijing's skyline.  In fact, ManufactureThis tracked the clean-up of Beijing at the time, courtesy of blog reports from The Atlantic's Jim Fallows.

The result was that, during the Olympics, Beijing remained fairly smog-free.

Unfortunately, after the Olympics ended, it was business as usual again.  The smog returned.

The Wall Street Journal's Bob Davis reports that Beijing is back to experiencing unsafe air conditions:

Beijing spent more than $10 billion to clean up its sometime spooky brown polluted air before the Olympics. According to the study, the government managed to improve air quality by 30% during the games, compared to year-earlier readings. But a year after the games, about 60% of those gains had evaporated.

Davis says that the brief window of cleaner air was due to "China’s authoritarian system."  Beijing made an effort because it was "motivated to do so."  Thanks to "the largest natural experiment in air cleaning...Coal, steel and chemical plants were shuttered, vehicle traffic was reduced and auto-emission standards were increased."

Once the motivation to have clean air was gone, emissions standards were once again discarded.  Now, as the picture above shows, Beijing is looking pretty murky again.

In 2009, the Alliance for American Manufacturing (AAM) released a report on China's steel industry and serious flaws in its pollution-control regime.  China’s rapidly growing steel industry suffers from ineffective enforcement of weak pollution-control standards and failure to use adequate pollution-prevention measures.  It's little wonder that one of China's leading exports is now smog.

Read the full Wall Street Journal article on Beijing's pollution problem.