Among the 10 major ecological achievements in China in 2014, the effective efforts to keep the sky blue and air clean during the Asia-Pacific Economic Cooperation meetings has been highly regarded, the event organizer said.

China Ecological Civilization Research and Promotion Association, a green NGO under the Ministry of Environmental Protection has included APEC blue in its list of the 10 major accomplishments achieved in 2014 released on Thursday.

The concentration of PM2.5, the major airborne pollutants, was reduced by 55 percent than during the same period in 2013, making the air quality during the period the best in the past five years in Beijing.

To make the sky blue, more than 9,200 companies in key industries suspended production and more than 40,000 construction sites stopped working to reduce dust in six areas including Beijing and Hebei province.

Though the APEC Blue was only temporary, the government has realized the effective effort and has started to extend measures to keep the amazing air quality longer, said Wang Chunyi, the assistant to the president of the CECRPA.

The 10 achievements also included the release of China's timetable on carbon dioxide emissions, saying the country will reach the emission peak by 2030.