China warned residents across a large part of northern China on Friday to prepare for a wave of choking smog arriving over the weekend, the worst of which is expected to over Beijing, prompting the capital to issue its second-ever red alert.
The red alert — the most serious warning on a four-tier system adopted a little over two years ago — means authorities have forecast more than three consecutive days of severe smog.
The National Meteorological Center said the smog would stretch from Xian, home to the Terracotta Warriors, across part of central China, through Beijing and up into Shenyang and Harbin in China's frigid northeast.
The pollution is expected to begin appearing on Saturday evening and last until Tuesday, with visibility in the worst affected areas such as Beijing likely to fall to less than 0.6 miles, it said.
In Beijing and parts of Hebei province, which surrounds the capital, the pollution index will probably exceed 500, it said. At levels higher than 300, residents are encouraged to remain indoors, according to government guidelines.
Beijing officials issued the first red alert last week, which was the second time this month that notoriously polluted Beijing experienced a prolonged bout of smog, sending PM2.5 (particulate matter 2.5 microns or less in diameter) levels in the suburbs as high as 976 micrograms per cubic meter. Beijing was also shrouded in persistent smog for most of November, when power demand soared because of unusually cold weather.
A red alert is triggered when the government believes air quality will surpass a level of 200 on an air quality index that measures various pollutants for at least three days. The U.S. government deems a level of more than 200 “very unhealthy.”
In Beijing a red alert means about half the vehicles are removed from the roads, schools are recommended to close and outdoor construction banned.
Beijing is not the only city to have a colored alert system, and the restrictions rolled out in the most severe cases are broadly similar.
Beijing's neighboring city of Tianjin also aims to remove about half its cars from the road in the event of a red alert.
Shenyang said it was issuing an orange warning for the weekend, meaning it recommended people not spend too much time outdoors, while the Harbin government said it expected generally clear skies over the coming days, with some smog spells.
After decades of unbridled economic growth, China's leadership has vowed to crack down on severe levels of air, water and soil pollution, including the heavy smog that often blankets major cities.
Most of the pollution is blamed on coal-fired power plants, along with vehicle emissions and construction and factory work. China, the world's biggest carbon emitter, plans to upgrade coal power plants over the next five years to tackle the problem but that may not help much. Beijing says its emissions will peak around 2030. For now, China depends on coal for more than 60 percent of its power.
Beijing's second red alert comes after a landmark climate agreement was reached in Paris this month, setting a course to move away from a fossil-fuel-driven economy within decades in a bid to arrest global warming.
Although the four-tier smog warning system was launched two years ago, Beijing had not issued a red alert until last week, drawing accusations that it was ignoring serious bouts of smog to avoid the economic costs of confronting the problem.
Some residents have defied the odd-even license plate number traffic restrictions to keep vehicles off the road and complained about the need to stay home from work to stay with housebound children. Others have used the break from school to travel to locales where the air is better.
Scientific studies attribute 1.4 million premature deaths per year to China's smog, or almost 4,000 per day.
Environmental Protection Minister Chen Jining vowed earlier this month to punish agencies and officials for any failure to implement a pollution emergency response plan quickly, the state-run Global Times tabloid said, and on Thursday police detained 10 company officials for fabricating pollution data.
Eight firms, from a sewage plant in the southern city of Dongguan to a Coca-Cola joint venture in northwestern Gansu province, were accused of using fake figures to hinder or manipulate environment checks, the Ministry of Environmental Protection said on its website.
Special law enforcement teams from the ministry uncovered the cases, it said, adding that the firms "unscrupulously" falsified data, in a bid to evade regulations.
The ministry said some of the companies involved may face criminal lawsuits. Chinese law prescribes jail terms of up to seven years for pollution offenders, state news agency Xinhua said.
Zhao Yanhong, a representative of Coca-Cola in China, said the case involving the joint venture happened in October and was handled by regional authorities, with a detained employee of the joint venture being released after five days.
"We've promptly accepted the criticism and rectification," Zhao added.
Al Jazeera and wire services