Beijing has set its mind to clear up the air and hopefully bidding for the2022 Winter Olympic Games is expected to help speed up the process.

The Beijing government recently announced the improved air quality in the past four months and to build on it, has invited former NBA star Stephon Marbury to speak for their cause.

On Monday, Marbury, now a leading player in Beijing Duck, became Beijing Environment Protection Ambassador to promote a more environmental-friendly life style.

"I just basically continue to encourage people to go green, mean taking the subway, puttingtrashes inside the right cans. All these stuffs are important to the environment," said Marbury who was spotted going to training by taking the subway.

"I believe the government here definitely take acts and take notice of trying to clear theair. So being a part of this is, anything they need me to do, I'm willing to do help," said the American who has well settled in here and is seen as a city hero after leading Beijing Duck to the third league champion.

Marbury said his home country the United States once was bothered by air pollution.

"In America, they had air problems as well in past years a long time ago and it resolvedproblem. I know it's a possibility that the air problem can change here," said the two-time NBA All-Star player.

"Often my friends ask me about air quality here in Beijing, I often tell them that it's getting better," said the 38-year-old who had his contract extended to 2017.

"I feels good, I'm used to be here, used to be a part of Beijing, so it's natural for me now, it's not like when I first came here. This is a home for me."

Last week, Beijing Municipal Environmental Protection Bureau (BMEPB) announced that the average density of PM 2.5 (airborne particles smaller than 2.5 microns in diameter)dropped by 19 percent compared with the same period last year.

This is good news for Beijing's bidding committee who are anxiously waiting for the evaluation report by the International Olympic Committee to be released next month.

The IOC will vote for the host city on July 31, choosing the winner between Beijing and Almaty, Kazakhstan.