For weeks northern China has been covered in a thick toxic smog. It is one of the worst episodes of air pollution the country has seen, affecting 460 million people.

Coal is the major cause, and will continue to be the country's biggest source of energy and air pollution. Although billions have been pledged for renewable energy, 200 new coal power plants will be built across the country.

For the last month, severe air pollution has choked Beijing and coal is estimated to cause about 40 per cent of the smog in the nation's capital.

Other cities in the north, such as Shijiazhuang, have recorded air quality of 1000 PM2.5. PM2.5 are fine particles less than 2.5 micrometres in diameter that can lodge in the lungs and get into the bloodstream. The World Health Organisation says anything over 25 PM2.5 as a health hazard.

Pollution prompts rare display of anger

People are frustrated because air quality was improving in 2016 until coal production ramped up in September to service a mini stimulus package for heavy industries.

Cheap coal has powered China's economic miracle and still provides 70 per cent of the country's energy. The Government is reluctant to wean itself off coal, fearing unemployment and unrest.

In a rare display of anger, China's rising middle class took to the Chinese social media website "wechat", demanding the Government take action and protect the children of China.

They said the Government's "war on pollution", now in its third year, has not delivered results.

In 24 hours last week a petition asking the Government to install air filtration systems in schools gathered nearly half a million views and more than 2,700 comments before it was shut down.

And there is good reason to be concerned — studies suggest more than one million people die prematurely every year from the toxic air that has engulfed northern China.

Beijing has implemented restrictions on construction, production and traffic in Beijing in response to the smog ( Reuters: Jason Lee )

China's addiction to coal shows no signs of slowing. China produces and consumes more coal that the rest of the world combined.

In the winter its citizens use the most. Like many in northern China, Li Yuan said he had no choice but to burn coal to keep warm. He cannot afford electricity or gas — coal is a quarter of the price.

"Using coal is not good. It's dirty. You touch it and your hands get black," he said.

"Electricity, you just need [to] turn it on but it's too expensive."

But the biggest air polluters are the coal-fired powered stations that ring Beijing. There are about 22 major plants, working overtime to service the increase in production of steel and cement and also to provide additional electricity to the cities and homes in northern China during the winter months.

The Chinese Government is telling the world it will dramatically slash its coal production, and last week announced it would spend 2.5 trillion yuan ($489 billion) on renewable energy to ease the pollution crisis.

But the reality is China has big plans for coal. Two hundred coal-fired power plants will be built in the coming decade. Some of the older plants will be decommissioned, but even by 2020 coal capacity is estimated to increase by 20 per cent.

Coal-fired plants leave little room for renewables

Critics like Dong Liansai from Greenpeace East Asia say renewable energy will not be able to compete with the all-powerful coal lobby.

"Energy demand is a fixed number and if we are adding too many coal projects there is going to be less space for renewables to develop," he said.

Anger is also increasing for those who live around the power plants. Yan Jingron lives right next to Sanhe Power plant in Lang Fang, about 70 kilometres out of Beijing, but is deeply worried about what he sees pouring out of the plant's smoke stacks.

"Is it dust or chemicals? I know its not good for humans and I worry about my grandchild who goes to a kindergarten nearby the plant," he said.

"The Government should do something and not just give us empty promises. Every year it gets worse."

Today the northern winds have provided some relief to the residents of Beijing, blowing some of the pollution away. But they are bracing themselves for the next round of toxic smog which is meant to roll in later this week.