With the Olympic Games breathing down Beijing’s neck, the city is racing against the clock to ensure it meets one of the commitments it made when it won the bid for the games in 2001: blue skies. By Anumita Roychowdhury

China has introduced cleaner fuel standards in its capital Beijing, its latest effort to curb the city's notorious pollution ahead of the Olympic Games in August.

The Beijing government has finally decided to cut subway fares by about 30 percent amid efforts to boost public transport, ease road congestion and improve air quality ahead of the Olympics.

Despite a persistent gray haze, officials said Tuesday an exercise that removed more than 1 million private vehicles a day from Beijing's gridlocked streets was a success that could mean a clearer sky during next summer's Olympics.

Effectivity date: 30 December 2005

Atmospheric Environment, 38, 3443-3452, 2004

Atmospheric Environment, 40(18), 3251-3262, 2006

Atmospheric Research, 84, 265–279, 2006

Chinese Science Bulletin (SCI), 52, 608-615, 2007

Atmospheric Research, 84(2), 169-181, 2007

Atmospheric Environment, 41(2), 417-431, 2007