An action plan to reduce PM2.5 density this winter in major cities that have high pollution was released on Nov 12.

The plan requires 41 eastern cities in the Yangtze River Delta to reduce pollution by 2 percent and 11 northern cities of the Fenwei Plain region by 3 percent this winter.

This is a change from last year, when cities in the delta region were ordered to reduce pollution by 3 percent and Fenwei region cities by 4 percent.

The reduction of the percentages was partly because of the weather.

The Ministry of Ecology and Environment said that due to unfavorable meteorological conditions, the government needs to make more of an effort to offset negative impacts from the weather.

"We have more difficulties and pressures this year because of unfavorable weather," said ministry spokesman Liu Youbin.

"Higher temperatures and less rainfall since September have increased ozone density and made pollutants harder to disperse."

Dealing with main polluting sources, including chemical industries and coal-fired heating, will be priorities for the government in its antipollution fight.

Industries such as chemical, textile, dyeing, packaging, furniture and plastic products should redesign their manufacturing methods, update their facilities, replace polluting materials with green ones and improve their product quality.

The government will provide service and aid, and those who still can't meet standards will be removed from the market, the plan said.

Northern areas such as Hebei, Henan, Shanxi and Shaanxi provinces need to switch from coal-fired heating to environmentally friendly methods.

According to the plan, by the end of October, 5.24 million households in northern provinces including Hebei, Henan and Shandong had replaced their coal usage with greener methods, accounting for more than half the population.

The three-year action plan approved by the State Council in 2018 marked 2020 as the final year to achieve more blue skies.

The environment ministry with other State organs including the Ministry of Industry and Information Technology will set goals for polluted areas every year.

"Different cities will have different standards based on their conditions," Liu said.

"Those who fail to meet their air quality improvement targets will be held accountable."

The average concentration of PM2.5 in winter is about twice that of other seasons, so it is important to combat air pollution over the next few months, according to the environment ministry.

"In the coming months, we will make every effort to finish all tasks, reduce the emissions of air pollutants and ensure the completion of the targets to improve air quality in winter," Liu said.