WHEREVER there is coal, there will be fire.
For centuries, we have dug up the combustible rock to power our industries, and we continue to rely on it to light our homes and keep the wired world humming. But each year millions of tonnes of coal are burned inadvertently, too – in underground fires that even now rage out of control all over the world.
Nowhere is this on more dramatic display than here in Jharia, in India’s Jharkhand state, where underground fires have been burning for nearly a century. Dozens of fires are still active in the coal-rich region, exposing residents to a constant stream of air pollution that can include methane, sulphur and mercury. As the seams smoulder away, the ground above them becomes prone to collapse – taking with them any houses, roads or other infrastructure built on the surface.
China, the world’s largest coal-producing nation, has its own vast coal fires. A study published in 2009 by the US Geological Survey estimated that anywhere between 0.5 and 10 per cent of China’s coal supply may be on fire. And there are perhaps hundreds more fires going in the US. But numbers remain sketchy – even if the blazes start on the surface, they can quickly migrate underground and stay out of sight for years.
No one knows whether the sum of all the carbon emissions from such fires adds up to anything of consequence for climate change. Researchers who have guessed at the size of the global conflagration suggest it is only a tiny fraction of what we burn in our factories and power plants.