BEIJING // The air in the Chinese capital got steadily worse as last week drew to a close. Starting off with bright sunshine and blue skies on Sunday, it deteriorated as a grey smog cut visibility. By Wednesday morning, the US Embassy's online air pollution monitor classed the level of particulate matter as "very unhealthy" as concentrations had reached many times the level above which bad health effects start to be seen.
After several more days with bad smog, the pollution index remained at "very unhealthy" yesterday evening.
Air pollution can aggravate conditions such as asthma, cause short-term illnesses such as bronchitis, and has been linked to lung cancer and heart disease. Young people and the elderly are particulary vulnerable to the effects of poor air quality.
Last week's pollution was nothing unusual, either for Beijing or China as a whole, as the country suffers acutely poor air quality in most of its major cities.
While traffic is partly to blame, a major cause of the smog that afflicts Chinese urban areas and even often its countryside is the burning of coal, much of it in coal-fired power stations.
"There are very bad environmental implications in the country where [coal] is burned as well as where it's produced," said Jonathan Watts, an environmental journalist and author who last year released a book, When a Billion Chinese Jump, highlighting the damage being done to China's environment.
"You can see the smog," he said, gesturing across Beijing's hazy grey skyline.
Last year, despite overtaking the United States to become the country with the largest installed wind-energy capacity in the world, China accounted for 48 per cent of the world's coal use. Almost three-quarters of China's electricity generation capacity is from these plants.
As well as having almost twice the carbon footprint of gas-fired power plants per unit of energy generated, coal-fired power plants also lead to the release of large amounts of particulate matter and other pollutants including heavy metals.
These contribute to smog, acid rain and water contamination and have been linked to lung cancer and other conditions including birth defects.
With China's energy use having increased 11.2 per cent last year on the back of rapid economic growth, the country's use of coal continues to grow, despite the investments in renewable energy.
Indeed the Chinese Academy of Social Sciences has predicted China's coal consumption could double over the next decade, even though the Chinese government's five-year plan, released earlier this year, said the country aims to reduce carbon emissions per unit of gross domestic product by 17 per cent.
While China's western province of Xinjiang is thought to contain energy reserves totalling one trillion tonnes, and the country's total coal reserves are the third highest in the world, China is also buying more coal from abroad to feed its insatiable appetite, with imports tripling in 2009. Such is the demand for higher-grade foreign coal that a port is to be created in Washington state in the United States to ship to China tens of millions of tonnes of coal mined in Wyoming.
Brian Schweitzer, the governor of Montana, another major coal producer, said during a visit to Beijing last week that his state too would like to sell coal to China.
"We sell none to China. We would like to sell some," he said. "China is increasing its electricity capacity at the fastest rate in the world."
Instead of importing ever growing quantities from abroad, environmental groups would however prefer China to reduce its dependence upon coal, China's own reserves of which are thought to date back to the Jurassic geological period, which began 200 million years ago.
Earlier this year, Greenpeace in China released a report titled The True Cost of Coal - Coal Dust Storms, that warned that coal ash, produced by coal-fired power stations and containing toxic chemical elements such as lead, arsenic and selenium, is picked up from sites where it is dumped and spread by wind across China to major population centres such as Beijing, Shanghai and Hong Kong. One tonne of coal ash is produced for every four tonnes of coal burned and in total, China produced 373 million tonnes of the ash in 2009, according to Greenpeace.
"We don't see this ever being controlled," said Tom Wang, a spokesman for Greenpeace China. "When it comes to the spread of coal ash, the situation is not improving at all."
While in recent years local authorities, including in Beijing, have moved to replace dirtier coal-based heating systems with cleaner facilities using alternative fuels, environmentalists believe such clean-up efforts are being cancelled out by the relentless increase in coal consumption to generate electricity. They would like further emphasis on renewable energy sources and reduced reliance on cheap coal.
"We see at the moment there will be more consumption of coal [in China], whether it's domestic or imported from other countries," said Mr Wang.