Measures on reducing coal consumption and its emission should be the top priority in China's air pollution treatment, said experts during a seminar held by Greenpeace on Sunday in Beijing.

At least 85 percent of air pollution is caused by energy consumption issues, said Li Junfeng, director of the National Center for Climate Change Strategy and International Cooperation.

"Beijing, Tianjin, Hebei Province, the Yangtze River Delta and Henan Province jointly cover an area of more than 1 million square kilometers, with a population of some 900 million. These areas use 56 percent of China’s overall coal mining," he explained as to why smog continues to linger.

China consumed some 4 billion tons of coal in 2013, a number surging from 1.4 billion tons in 2003. Frederick Weston, director of the China program of the Regulatory Assistance Project, stressed that China burns half of the world’s total coal amount; electricity production accounts for half of China's coal use.

“He advised that coal quality specifications, including indicators such as Nox and Sox, should be taken into account when power plants purchase coal. Also, competitive bidding auctions could be conducted for new thermal generation to utilize the newest technology and cut down on emissions.”

Ma Jun, chief economist with Deutsche Bank Greater China, suggested that in order to reduce average annual PM2.5 levels in urban China from the current 65ppm to 30 ppm by 2030, clean emission reduction methods should be used to reduce the pollution emission of unit coal consumption by 70 percent, with a 6 percent annual decrease.

China is taking measures to control its air pollution, including limiting the number of vehicles on the road and suspending factory production, as the smog in many areas has once again persisted for days.

The National Meteorological Center (NMC) issued a yellow smog alert on Sunday morning, the fourth straight day such an alert has been announced.