Trying to put out hellfire on earth

It has been described as a vision of hell on earth.

Through a trembling haze of heat can be seen a bleak landscape scarred with cracks and fissures from which warm, choking smoke drifts into the air.

In deep pits below, tiny figures toil within the dust and fumes. The ground is hot enough to soften the soles of your boots. The cloying odour of burning sulphur pervades the air.

This is a typical scene at a coalfield where the underground fossil-fuel reserves have ignited.

The fires burn out of control, eating through the seams of coal and throwing out clouds of toxic fumes and greenhouse gases.

The problem of coal fires is serious - both for the communities living nearby and the wider environment. No one knows how many of these fires are burning in the world at any one time, but it numbers in the hundreds. Some have been burning for decades, if not centuries.

Scientists are developing new methods to track these fires in an attempt to identify those that pose the most danger to nearby populations. Remote sensing by satellites and aircraft is providing key information about the numbers of fires, and their severity.

"We do not know how many are burning", said Glenn Stracher, a professor of geology at East Georgia College in Swainsboro, Georgia, and an authority on coal fires. "But we do know that there are about 160 surface or underground fires in the US, between 20 and 60 in China, and in Indonesia as many as 1300."

There are also fires in South America, Russia, India and Europe. "Coal fires have killed people, forced communities to abandon their homes, destroyed habitats, and are responsible for perilous land subsidence," Stracher said.

The fires can start spontaneously, but are often caused by sparks from equipment, or even cigarettes, which can ignite methane and hydrogen.

"The consequences of these fires are terrible and that has not received the attention it deserves," said Stracher, who has analysed the composition of coal-fire smoke and identified many known cancer-causing agents within it.

It has been estimated that in China, about 200 million tonnes of coal is consumed in mine fires each year, accounting for around 2 to 3 per cent of global greenhouse gas emissions from fossil fuels.

In the Jharia coalfields of eastern India, fires are also a major problem, and at any given time there are about 70 burning within the coalfield.

Dr Anupma Prakash, a geologist at the University of Alaska Fairbanks, said the Jharia fields was the worst affected area in the world.

"It is a living hell. I have seen the conditions that the people are living in and it is shocking," said Prakash, who has been studying fires in this region for more than a decade.

Many villages within the coalfield sit on land directly above fires. As the coal is consumed, the land subsides. "You see houses on the edges of precipices where the ground has collapsed," Prakash said. "I have been in a house where smoke has been coming in through a crack in the wall and the wall itself is hot to the touch."

Stracher, too, has witnessed appalling conditions in communities living among coal fires.

"In South Africa I have stood at the edge of an open-cast mine where fires have been burning and looked down into the pit with people working among the smoke. I have had the soles of my boots melt in the heat. Kids play on the edge of these coal mines, inhaling this stuff day after day. How long are they going to live?"

The obvious question arises: why not simply extinguish the fires? The problem is that once an underground fire gets hold, it can be almost impossible to reach and put out. The fires themselves are huge and self-sustaining. As the ground above dries up, cracks appear that allow oxygen to filter down and feed the burning coal. Even in wealthy nations such as the US it can be deemed simply too big a problem to tackle.

In 1962 in Pennsylvania, a coal-mine fire started when rubbish that had been dumped in an abandoned mine entrance was set alight by workers. Vain attempts were made to extinguish the blaze and eventually the decision was taken to allow the fire to burn. Centralia was evacuated and now exists as a ghost town. The fire is still burning.

One US company has developed a fire-resistant gel-like substance that can be pumped around burning material to starve the fire of oxygen.

A Dutch-Australian company has built a system based on a jet engine to blast inert gas on to burning coal, suffocating the fire.

But both work only in some situations and not others.

More solutions may come as international concern mounts about greenhouse gases. As ideas about carbon trading across the world begin to take shape, incentives might exist for national governments to take action on coal fires.

- INDEPENDENT