Underground coal fires occur all over the planet, burning billions of tons of coal each year, releasing huge amounts of air pollution into the atmosphere. It is estimated that in 2010, 3 million people died worldwide due to air pollution, more than a million of these deaths happened in China, the world’s largest coal producer.
Burning coal for cooking or heating your home is banned in most developed areas of the world because of strong evidence of fumes being highly damaging. Meanwhile these underground fires burn away unnecessarily both underground and nearer the surface, new fires appear regularly but because they’re so difficult to extinguish many have been burning for hundreds of years and the oldest, Burning Mountain in Australia, is estimated to be over 6000 years old. The most well known example of a coal seam fire is Centralia, Pennsylvania where a fire in a garbage dump in 1962 spread to the mine, despite attempts to control the spread of fire none were successful so US congress allocated more than $46 million to help relocate residents. The town’s population dropped from over 2,700 to 6 as of now (2014). The mine is still burning more than 50 years later and there’s enough fuel to keep it going for another 600 years.
But why do these coal fires happen? Some fires are thought to have started naturally, it’s possible for coal to self ignite and in the case of Burning Mountain, it is believed the fire may have been started initially by lightning strike. But the majority are undoubtedly man-made. Mining exposes coal that would otherwise have been well and truly buried to the air which will then supplies the oxygen necessary for ignition. Bootleg mining was commonly dealt with in the past by blowing up the pits and in modern China, where bootleg mining is still common, competitors will regularly set each others mines alight.
According to the American Association for the Advancement of Science’s (AAAS), putting out the fires in China alone would cut CO2 emissions equivalent to the volume produced by all US cars in a year.
So why aren’t they being put out? Extinguishing them is both difficult and expensive. The fires can be so deep and wide-spread that digging them out simply isn’t an option and with temperatures reaching 1000 degrees Farenheit in places, attempts to do so would be incredibly dangerous. Most methods simply involve smothering the fires, using loess or clay to inhibit air flow to the coal and paving over the seams. Despite attempts, current methods are not working and better solutions are desperately needed.