Disadvantages
Basically, the main drawback of fossil fuels is pollution.
Burning any fossil fuel produces carbon dioxide, which contributes to the "greenhouse effect", warming the Earth.
Burning coal produces more carbon dioxide than burning oil or gas.
It also produces sulphur dioxide, a gas that contributes to acid rain. We can reduce this before releasing the waste gases into the atmosphere.
More details on 'clean coal technology' from BBC News web site...
Mining coal can be difficult and dangerous. Strip mining destroys large areas of the landscape.
Coal-fired power stations need huge amounts of fuel, which means train-loads of coal almost constantly. In order to cope with changing demands for power, the station needs reserves.
This means covering a large area of countryside next to the power station with piles of coal.