Now that sustainable development and the green economy have been widely adopted as articles of faith by many countries that want to achieve economic, social and environmental balance, the UNEP is helping those that want to put them into practice.

"Such policies have to be based on a comprehensive and careful assessment of the problem," Fabian says.

"For air pollution, developing stricter standards to regulate emissions from vehicles and industries is a must, and adopting the best available technologies, especially in key industries and vehicles, is critical in reducing air pollution. Better urban planning alongside active promotion of public transport and nonmotorized transport are also important."

A study by the World Bank and the Development Research Center of the State Council has estimated that air pollution in China can cost between $100 billion and $300 billion a year and cause up to 500,000 premature deaths, Fabian says.

With those kinds of sobering figures in mind, the Chinese government has committed to take more strenuous steps to reduce air pollution.

"The Air Pollution Prevention and Control Action Plan was launched with a budget of $280 billion, which will focus on limiting the use of coal and banning high-polluting vehicles," Fabian says. Last month China announced that 6 million cars would be taken off the road by 2017, showing its commitment to uphold the plan.

A green economy

A report on China's green economy outlook between 2010 and 2050 that the UNEP published this month says China has made undoubted progress over the past 10 years in creating a green economy.

The country has started transforming its economic growth to reflect green principles and will make growth more sustainable, but better coordination of green investment, consumption and technology is needed for better results, the report says.

Sheng Fulai, head of the Research and Partnerships Unit of UNEP in Geneva, says economic development and environmental protection are not mutually exclusive.