Beijing residents and their neighbours in Hebei province and Tianjin awoke to another round of smog on Wednesday – and the choking air pollution will only get worse this weekend, meteorological officials warn. They forecast on Tuesday that the heavy pollution would remain across the region for a week until a cold front cleared away the smog on November 16. Appalling air quality: Beijing takes deep breath as smog season sets in At noon on Wednesday, Beijing’s air quality index reading was at 220 – far above the heathy level of 25 for daily exposure stipulated by the World Health Organisation – meaning the air was severely polluted and unsuitable for outdoor activities. The dire warning came only two days after northern China was blanketed in thick smog last weekend, forcing the cancellation of several hundred flights to and from cities including Beijing. Authorities said more than 30 cities in six provinces would be affected by the latest smog outbreak, which they described as “rare” – in terms of its severity and the area affected – compared with other smog cases over the past four years. So far this year, public complaints about air pollution problems seem to have waned – at least on mainland social media platforms. Winter’s chill to spark Northern China’s coal heaters – and yet more smog However, one question remains unanswered: why – despite government pledges and heavy investment spent on dealing with the continuing problem – does the smog keep returning? Beijing set up an air pollution clean-up fund of 760 billion yuan in 2014, with its then-mayor Wang Anshun promising that the city’s smog problem will be solved by 2017. Yet as the end of 2016 approaches, environmental authorities are forecasting that northern China will face more severe smog problems this winter than usual. They said the influence of stable atmospheric conditions would prevent pollutants from being dispersed by El Nino. El Nino is an abnormal warming of waters in the equatorial Pacific that occurs once every three to four years, typically in December. Its effects can include the reversal of wind patterns across the Pacific, drought in Australasia, and unseasonal heavy rain in South America. Thick choking smog returns to blanket Beijing, visibility falls below 100 metres Chai Fahe, former deputy head of the Chinese Research Academy of Environmental Sciences, admitted the huge quantity of pollutants that were emitted into the atmosphere remained the main cause of severe smog. The problem is often compounded when there is little wind or rainfall. Vehicle exhaust fumes, emissions from factories, and the burning of biomass and coal – especially the burning of coal by rural households for heating during winter – are listed as major causes of the pollution. The Ministry of Environmental Protection has blamed local authorities in several northeastern cities for failing to launch emergency responses when smog has formed. It has also asked foundries, cement factories and brick kilns to reduce production until March. However, the frequent appearance of choking air pollution appears to point to one major problem: the implementation of clean-up measures involving factories, households and vehicles is often poor – sometimes non-existent - and local supervision is lax. Local governments have reportedly falsified their environmental monitoring data to impress the central leadership as officials are now also rated for their achievements in protecting the environment. Meanwhile, Hebei province has punished 487 officials, including four at senior levels, for abusing their power or failing their supervision responsibilities on environmental protection. According to an official statement yesterday, the officials, who were at government agencies or state-owned companies, either granted approval for polluting projects that should not have been put online, forged documents to keep outdated plants in operation, or allowed the construction of new plants without the proper permits.