Images of the Beijing skyline seemingly bathed in a soup of smog and haze have been a common sight on the world's TV screens in recent days and weeks.

Foreign journalists with hand-held air pollution detectors have been popping up on street corners checking levels of soot and dust. Everyone seems keen to prove that the city's air will be a decisive and debilitating factor for one of the world's most high-profile sporting events.

Without doubt Beijing is facing a huge challenge. There are real and understandable concerns for the health of competitors, especially those in endurance and long-distance events such as cycling and the marathon.

But the current frenzied focus is marked by considerable amnesia. After all, air pollution was a major concern in Los Angeles 24 years ago, though few now seem to recall the dramatic scene at the end of the women's marathon, when the Swiss competitor was seen staggering and stumbling from exhaustion, the heat, and, perhaps, the effects of air pollution.

And air quality was also an issue for subsequent Olympic Games in Barcelona, Atlanta, Seoul, and Athens.

So the debate about the Beijing Games deserves more fair play than it has received.

Indeed, real and, one hopes, long-lasting achievements have been made by the Beijing Organizing Committee for the Olympic Games, the city as a whole, the government, and the six provinces concerned. This is all the more remarkable when set against the city's double-digit economic growth and the fact that the Games are being staged in a developing country, with all the social, economic, health, and environmental challenges this entails.

For example, some 200 polluting factories have been closed, switched to new kinds of cleaner production, or moved out of the city over the past seven years. Moreover, as a result of a $17 billion investment, more than 90 percent of the city's wastewater is now treated, more than 50 percent of the city is forested, and natural gas accounts for more than 60 percent of energy generation, up from roughly 45 percent in 2000.

Meanwhile, eight railway lines, covering 200 km and with a daily capacity of close to 4 million people, have become operational this year, alongside 60 km of bus lines. New vehicle emission standards meet the most stringent equivalent European standards, and are higher than in the United States.

In addition, 50,000 old taxis and 10,000 buses have been replaced, and 4,000 of the new buses are powered by natural gas – now the largest fleet of its kind in the world. In recent days, the authorities have also requested businesses to stagger the working day before, during, and after the Games to reduce traffic volumes, alongside a raft of other traffic-cutting measures.

Then there is the attention to eco-detail at the Olympic venues themselves, including the 400,000-sq m Olympic Village, where water reclaimed from the Qinghe sewage treatment plant is being used for heating and cooling systems, resulting in an estimated 60 percent savings in electricity consumption.

Only time will tell if all these measures will bring air pollution down to acceptable levels. The United Nations Environment Program will certainly make this a focus of its post-Games report, building on the initial one issued last year.

But it is clear that Beijing is striving to be part of the Green Team, embracing environmental standards that are now central to the modern Olympic movement, and that are increasingly part of other big sporting events, such as the Green Goals for the 2006 and 2010 FIFA World Cups.

Increased public awareness, the ability to showcase new and more sustainable ways of managing an urban setting, and the legacy of more environmentally friendly energy, transport systems, and other infrastructure should also not be underestimated.

Humanity is currently engaged in a far-reaching and urgent competition that pits the need to embed a twenty-first century "green economy" against the rapid implosion of our climate and natural life-support systems. The catalytic and inspirational possibilities of events like the Olympics thus have a wider role to play, one that might just help prevent us from staggering and collapsing under the weight of our environmental degradation.

The author is Under-Secretary General of the United Nations and Executive Director of the United Nations Environment Program (UNEP), which is assisting the Beijing Organizing Committee on environmental issues Project Syndicate

(China Daily August 9, 2008)