One of the intriguing questions sinologists might ponder this week, as the Chinese Communist Party holds its party congress, is if climate change is on the agenda.

Given the shadowy world of Chinese politics, it is hard to know. "The Communist Party is at an odd junction right now," says Laurie Garrett, a senior fellow at the Council on Foreign Relations in New York. "They're very divided about exactly how much more of this full-steam-ahead economic development they can do without reining some of it in."

For China's extraordinary progress has bequeathed a monstrous legacy of environmental degradation.

Last week China's state media admitted that the massive Three Gorges Dam, a showpiece engineering feat on the Yangtze River, threatens "environmental catastrophe," necessitating the evacuation of four million people.

This blow is hardly welcome as the world's media focuses on next year's Olympics. But therein, believes Garrett, lies an eco-opportunity for President Hu Jintao.

"For if there's one thing they're all united around," she says, "it is the absolute importance of the Beijing Olympics to the future image of China. I don't think any Chinese leader believes it will be in the national interest for Beijing's smog levels to be so high that in, say, the marathon CNN or NBC cameramen can't see the runners."

In a nation where mass spectacle has long been part of communist pageantry, the Olympics are envisaged as a dazzling debut meant to impress the world. But if China ignores Beijing's dire air quality a media debacle is possible. In August, Jacques Rogge, the president of the International Olympic Committee, warned China that unless improvements were made, "endurance sports like cycling might be postponed or delayed".

In the tradition of epic central planning, China is plotting a huge clean-up in Beijing to create a "blue skies" Olympics. Several weeks before the games start pollution-spewing industries and factories in the greater Beijing area will be slowed or shut down. Traffic flow will be severely reduced. Clouds may be seeded to reduce the impact of Mongolian dust storms. Millions of trees are being planted to help cleanse the air.

In a recent Los Angeles Times article Garrett and Jane C. S. Long, associate director of the Lawrence Livermore National Laboratory, suggest this clean-up "provides a once-in-a-lifetime for science" to conduct a "great experiment".

They advocate a moratorium on greenhouse gases like carbon dioxide to see if climate change can be reversed.

Pollution levels would be monitored before, during and after the games, especially downwind of Beijing. The data would provide scientists with information to tackle climate change, and issues such as public health, particularly respiratory diseases.

The key thing, says Garrett, is to couch such massive monitoring, which could use Nasa and EU satellites, in a way that makes China feel "it is co-operating in a great experiment in which it has a stake".