Women wear masks for protection against the pollution as they walk along a street on a polluted day in Beijing, Sunday, December 13, 2015. China's push for a global climate pact is partly because of its own increasingly pressing need to solve serious environmental problems, observers said Sunday. (Photo by Andy Wong/AP Photo)





In this December 12, 2015 file photo, a scrap collector gathers materials in a demolished neighborhood near a chimney spewing smoke in Beijing, China. China's push for a global climate pact is partly because of its own increasingly pressing need to solve its serious environmental problems, observers said Sunday, Dec. 13, as China said the Paris deal shows it is dealing with climate change “as a responsible big country”. (Photo by Ng Han Guan/AP Photo)





A Roewe E50 electric car is parked next to a street as a bicycle travels past, amid heavy smog, after the city issued its first ever "red alert" for air pollution in Beijing, China, December 9, 2015. (Photo by Damir Sagolj/Reuters)





Tian Honglei (C), a migrant worker from Henan province, holds a placard as he marches with his fellow workers along a main street to protest against a construction site and demand their salaries, in central Beijing, China, December 10, 2015. A total of 32 construction workers took to the street on Thursday to demand a construction site in Xianghe county of Hebei province to pay what they say are their delayed salaries worth about a total of 660,000 yuan (102,510 USD). The Chinese characters on the placard read, “Delay migrant worker salary, demanding payments”. (Photo by Jason Lee/Reuters)






People chat between shops in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





Women work in their home in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





A migrant worker steps out of his accommodation in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





A man walks between houses in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





A migrant worker brushes teeth outside his accommodation in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





A woman works in a shop at an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





A woman hangs clothes in an abandoned kindergarden next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





Men deliver honeycomb briquettes for domestic use in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





Migrant workers exchange some food at their accommodation in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





A man carries a large toy between houses in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution December 10, 2015. (Photo by Damir Sagolj/Reuters)





A migrant worker steps out of his accommodation in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





A migrant worker washes his face in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





Women pass by clothes hanging outside in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





A worker enters a workshop next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





Women share a laugh in an area next to a coal power plant in Beijing during a smog-free and also the last day of the city's first "red alert" for air pollution, December 10, 2015. (Photo by Damir Sagolj/Reuters)





Residents on their bicycles and electric bikes wait for the traffic at an intersection amid heavy smog in Shijiazhuang, Hebei province, China, December 10, 2015. (Photo by Reuters/Stringer)





Customers crowd to buy bamboo shoots at a supermarket on the “Double 12” shopping festival in Hangzhou, Zhejiang province, China, December 12, 2015. Many supermarkets in China cooperated with Alipay, the online payment platform of Alibaba Group, on this festival to offer their customers 50% off up to 50 yuan ($7.74), local media reported. Alipay's wallet system is widely used in both retail shops and for online transactions. (Photo by Reuters/Stringer)





Customers wait in line to check out at a supermarket on the “Double 12” shopping festival in Hangzhou, Zhejiang province, China, December 12, 2015. (Photo by Reuters/Stringer)





Residents push a bus which is stranded on a snow-covered street uphill as heavy snowfall hit Urumqi, Xinjiang Uighur Autonomous Region, China, December 11, 2015. (Photo by Reuters/Stringer)





A woman pulls a cart carrying a child on a snow-covered street as heavy snowfall hit Urumqi, Xinjiang Uighur Autonomous Region, China, December 11, 2015. Picture taken December 11, 2015. (Photo by Reuters/Stringer)





A security guard cleans a car on a street in Shanghai, China, December 14, 2015. (Photo by Aly Song/Reuters)





Anti-terrorism paramilitary policemen take part in a drill in Changsha, Hunan province, December 12, 2015. (Photo by Reuters/Stringer)





Police and civilians take part in an anti-terrorism drill at a college in Hangzhou, Zhejiang province, China December 10, 2015. (Photo by Reuters/Stringer)





Police and civilians take part in an anti-terrorism drill at a college in Hangzhou, Zhejiang province, China December 10, 2015. (Photo by Reuters/Stringer)





Police and civilians take part in an anti-terrorism drill at a college in Hangzhou, Zhejiang province, China December 10, 2015. (Photo by Reuters/Stringer)





A man rides his loaded tricycle next to three schoolgirls in Shanghai on December 11, 2015. (Photo by Johannes Eisele/AFP Photo)