[MargaretR]

There are signs that this may make coal mining economically viable again.
We have plenty of that still unmined in Uk.
Whether or not it will happen depends a lot on whether we will have to stick rigidly to carbon emissions targets, and whether new coal fired power stations will be allowed to be built.
It seems illogical not to use coal, when it comes down to 'heat or eat' we may have to.
Perhaps the reduction in car use will compensate for the emissions from coal fired generation of electricity - I am not an expert - just clutching at straws