Terry Macalister on the global resurgence of coal as an energy source
The last couple of years has seen a massive swing towards king coal after decades when it looked doomed to be phased out, because of acid rain and then greenhouse gases, of which it is a huge emitter. Its use in US power stations alone is responsible for 1.5bn tonnes of CO2 emissions a year.
Despite mounting fears about carbon pollution, coal has returned to fashion because rival energy sources such as gas are soaring in price and being depleted faster than expected. Coal reserves are also often located in politically stable countries such as the US, South Africa and Australia.
Coal, which has traditionally been a cheap power source, is also prized as a fuel for electricity generation because it does not have the problem of intermittency of supply associated with solar or wind, and plants do not have to be kept running all the time as they do with nuclear power.
A major study published recently by the Massachusetts Institute of Technology, called The Future of Coal concluded: "We believe that coal use will increase under any foreseeable scenario because it is cheap and abundant. Coal can provide usable energy at a cost of between $1 and $2 [£0.52 to 1.04] per million British thermal units (MMBTU) compared to $6 to $12 per MMBTU for oil and natural gas."
Coal reserves worldwide are as high as 909bn tonnes, according the BP Statistical Review of World Energy 2007, which at the current rate of production of less than 6bn tonnes per year, would last for over 150 years.