Beijing's environmental performance ranks fifth among China's 289 cities above prefecture level, making it the only city in North China in the top 20, according to a study by international experts.

Shenzhen, Xiamen and Haikou are the top three most eco-friendly cities, according to the Green China Urbanization Index, which was released by the Japan-based think tank Cloud River Urban Research Institute during the Fourth Global Think Tank Summit in Beijing in late June.

Beijing's ranking may conflict with public sentiment, however, as air pollution has become a great concern of the public.