We have seen some big technological advances in the past few years and their positive impact on the environment will be seen during and long after the Games, she says.

Beijing will ban cars that don't meet the Euro IV emission standard before the Games next year. Also, the government will pull out 2,580 buses and more than 5,000 taxis from the roads by the end of this month.

The new emission standard will help the city cut pollutants such as sulfur dioxide (SO2) and nitrogen oxide (N2O). This will be a welcome change because Beijing already has 3.06 million registered vehicles, with about 1,000 new ones being booked every day.

It will be important also because the city is exposed to about 1.3 million tons of pollutants like carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbons discharged by vehicles every year.

Thankfully, the city's coal-fired heating system has been phased out, and by next year, the supply of natural gas will reach 5 billion cubic meters (m3), up from 3.8 m3 last year and 1 billion m3 in 2000.

The treatment rate of wastewater in the capital's suburban areas reached 90 percent last year, meeting the goal set for 2008. The target for garbage treatment for next year has been set at 98 percent, and by last year 96.5 percent was being treated.

The UN has said Beijing's bid for the Olympics was notable for the broad reach of its environmental commitments, which ranged far beyond the immediate concerns of planning just for the Games to an ambitious program for cleaning and greening the city.

As the IOC Evaluation Committee noted in 2001, Beijing's proposed measures, if implemented, would leave "a major environmental legacy".

UN Under Secretary-General and UN Environmental Programme (UNEP) Executive Director Achim Steiner says: "Where we have comments or reservations, we have stated them clearly. But there is no doubt that, with less than one year to go before the Olympics, Beijing is on track to deliver on its environmental promises."

Beijing has already met many of its commitments such as waste-water treatment, waste management and protecting its water sources, and appears to be well on way to fulfilling the rest of them, Steiner says.

"This in itself is an achievement, especially considering that the organizing committee of the previous Olympic Games failed to follow up on its environmental promises," says UNEP in its recent assessment report.