In this Dec. 29, 2016 photo, a man walks near the Shougang steel mills in Qianan in northern China's Hebei province. Faced with choking smog in the Chinese capital, Chinese media and policy circles often point to a list of culprits: the central government's inability to shut down polluting steel mills, the middle class's insatiable demand for cars, poorer segments of society's insistence on burning coal. (AP Photo/Ng Han Guan)