Pollution highlights China energy problem
China continues its battle against toxic air pollution that has covered Beijing on several days in the past few weeks.
The government has temporarily closed hundreds of factories and ordered some cars off the road.
But Xizhou Zhou, head of China Energy at IHS CERA in Beijing, tells the BBC that the issue is a long term problem that must be dealt with.
China's hazardous air quality stems mainly from its dependence on coal, which, despite massive expenditure on renewable energy projects, remains the country's default fuel.
Coal currently provides about 70% of the China's energy, and demand is expected to triple by 2030 according to some estimates.