Fri July 27, 2012

Did Beijing Medal In Pollution Cuts?

As the Summer Olympic Games get underway today in London, researchers at the National Center for Atmospheric Research in Boulder have been looking back to the last games. The effort to clear the skies in Beijing was also a perfect experiment for climate scientists.

The concern four years ago was that smog would sicken elite marathoners and cyclists, and tar Beijing’s coming out party. So the Chinese government told drivers they could only be on the road every other day.

NCAR scientists, including atmospheric chemist Helen Worden, wondered just how much of a dent that made to global greenhouse gas emissions.

“It was a rare opportunity to study transportation in an actual urban setting, and how much CO2 was reduced,” says Worden.

Satellite measurements of carbon monoxide allowed researchers to calculate carbon dioxide levels.
Credit Lex Ivey / UCAR

Worden used satellite measurements and computer models to calculate that the drop was roughly 60,000 metric tons of carbon dioxide per day. That’s about was a quarter of one percent of what’s needed to keep the planet from warming to dangerous levels. While that may not sound like a lot, it’s also the result of action in just one city.

“We didn’t know what to expect,” says Worden, “so we were a little surprised it was that significant.”

The result suggests that aggressive steps to limit car emissions in many more cities would play a large part in preventing climate change.

“If you’re revising a current transportation plan for a city,” says Worden, “this gives you further incentive, while you’re trying to solve the issues of congestion and air quality, that this gives you another benefit.”

The biggest worry for the Olympic hosts in London this year is also in the sky, but unlike Beijing, there’s not much the British can do about rain.

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