A resident walks through an overpass amid heavy smog and thick fog in Beijing, Dec. 25, 2015. (Photo: China News Service/Sheng Jiapeng)
Frequent winter smog in northern China has shown the war on pollution will be arduous and call for greater efforts.
In a severe bout of smog last month, 40 cities in north China issued alerts for air pollution. Beijing, along with the cities of Baoding, Handan, Langfang and Xingtai in the neighboring province of Hebei, issued red alerts, the most serious in the four-tier warning system.
Although the breakdown of the smog's sources -- including weather conditions, motor vehicle exhaust and industrial waste -- varies across China, growing winter coal consumption is one of the major factors in the haze.
Monitoring data showed substances directly related to coal burning, including sulfate and black charcoal, are major components of PM2.5, airborne particles smaller than 2.5 microns in diameter, that can penetrate deep into the lungs.
Beneath the rising PM2.5 density is the "inconvenient truth" of China's coal-powered economy: although the country's coal output fell in 2014 for the first time this century, the volume of nearly 4 billion tonnes is still massive.
Coal consumption accounts for about 66 percent of China's primary energy consumption, 35 percentage points higher than the world average.
In the country's north, where pollution is most rampant, coal use accounted for more than 80 percent of energy consumption.
"The proportion of coal in China's primary energy mix is equal to that of the global energy structure almost a century ago, which is indeed worrisome, but also means there are opportunities," noted Huang Xiaoyong, director of the global energy security research center under the Graduate School of the Chinese Academy of Social Sciences.
