As the world's biggest carmaker and consumer of automobiles since 2009, China has seen car exhaust fumes quickly rise to become the biggest polluter in major cities. How to reduce air pollution from exhaust gases has become the toughest challenge Chins has to take.

For the first time, the Ministry of Environmental Protection has published the figures of motor vehicle exhaust emissions. The total amount of fumes discharged from motor vehicles in 2009 was more than 50 million tons, and of the 113 key cities for environmental protection, the air quality of one third does not reach the required standard. Acid rains and heavy smog occur frequently in some major cities.

Compared with the early 1980s when reform and opening-up were first launched, the total number of motor vehicles has increased by 25 times and reached 170 million in 2009. The more than 40 million tons of carbon dioxide, nearly 5 million tons of hydrocarbon, 5.8 million tons of hydro-nitrogen and 59 tons of floating particles, along with the gases produced by the burning of coal, have made it ever more difficult to reduce air pollution.

The automobile industry has contributed a great deal to the country's economic growth and to the improving of people's living standards. It is now one of the most important pillars of the country's industry.

And in the past decade, standards for car exhaustion emission have been upgraded from level one to level three. The amount of fumes discharged from new cars with small capacity engines manufactured in 2009 decreased by 90 percent, compared with the cars of the same type manufactured in 2000.

However, the number of motor vehicles is still rapidly increasing. The total cars manufactured and sold surpassed 13 million from January to September this year. The total number of cars will reach 200 million nationwide by 2020.

Undoubtedly, the pressure is growing to deal with air pollution caused by exhaust fumes discharged from cars.

Apart from upgrading technology to reduce the amount of fumes emitted from cars and the manufacture of motor vehicles using alternative fuels, it is undoubtedly necessary to intensify publicity to bring home the awareness of environmental protection among citizens.

At the same time, governments at all levels need to have incentive policies to encourage residents to use public transit and other environmentally friendly transport, such as bicycles. More investment also needs to be put into public transport to make it easier for residents to travel by bus or by subway.

Urban planners must change their mentality and stop repeatedly widening roads to make room for motor vehicles. Instead, more money and efforts must be shifted to public transport means. That is the way to achieve cleaner air in cities.