Electricity.
I think we have to get used to the fact that simply finding something else to burn is not the way forward.
Sufficient energy can be produced without polluting, IE solar, wind, geothermal etc. but major lifestyle changes must come with it, it's seriously time to realise that we cannot continue to consume resources like this for much longer, irrespective of the fact we have enough coal for centuries and ways to produce oil for futher decades.
Eventually the other 5 billion( possibly 8-9 billion by that time) people who aren't as "developed" as the west will catch up.
Then what?