Local officials will be held accountable for any failure in achieving their air pollution targets as the country resolutely moves forward in the blue sky protection campaign, a national political adviser and senior environmental official told reporters on Tuesday, adding that the government was taking the war against air pollution seriously.

With a series of measures taken in 2018, China made great achievement in improving its air quality last year. The average density of PM 2.5 in the country fell by 10.4 percent year–on-year. The concentration of the pollutant in Beijing reached 51 micrograms per cubic meter, Liu Bingjiang, head of air pollution control at the Ministry of Ecology and Environment, told a news conference.

To achieve that, China has greatly increased the use of clean energies while enhancing the efficiency of coal burning in power generation. Coal covered 59 percent of sources of primary energy consumption in 2018. It’s the first time that the country saw the coverage decrease to less than 60 percent, said Liu.

A total of 23,000 coal-fueled small boilers were phased out across the country in 2018. In northern China, over 4.8 million rural households had shifted from coal to clean energies to warm up their homes, he added.

Liu said he is confident that China could achieve the target it sets for 2020, which asks for an 18 percent decrease in PM 2.5 density in major cities that have yet to keep the level below 35 mg/cu m.

Almost no cities around the world has once managed to reduce PM 2.5 concentration by over 10 mg/ cu m in just one year, but Beijing successfully brought the density down from 73 mg/cu m in 2016 to 58 mg/ cu b in 2017. "This is a miracle that we have never sees in history," he said, adding this shows that the steps the government has taken are efficient and will also contribute to future air pollution control work.

He said what also makes him confident is that more than 2,000 leading Chinese experts have been devoting themselves into site investigation over the causes of air pollution in 39 major Chinese cities in Beijing-Hebei-Tianjin cluster. They are drafting tailor-made solutions for each of the cities to facilitate their effort in improving local air quality.

Liu said the country saw the PM 2.5 density in some regions increase again in January and February, and some key regions witnessed a deteriorating situation. This occurred partly due to El Nino, which resulted in transportation of water vapor to northern China with help of weak wind, making meteorological conditions favorable for smog generation.

Some local governments are now relaxing their effort in pollution control, saying that there should be rest even in a war. "We have explicitly said we are going to win the blue sky protection campaign. We have no plan to retreat," Liu said.

"There is no jesting in the war. We should keep our promise with action and there must be progress. Those who fail will be fully held accountable," he said.