Why should we worry about the tiny possibility that a few people in the future will die in the unlikely event that society regresses so much that we forget how to build a Geiger counter when air pollution caused by burning coal is killing tens of millions of people a year right now?
It might well be some teenage boys finding bright yellow coloured barrels with interesting symbols in a cave. Which teenage boy can read warnings written in Egyptian hieroglyphs?
That doesn't justify burning coal, however, there are many renewable energy sources that do not produce pollution or toxic waste that is hazardous for ten thousand years.
> there are many renewable energy sources that do not produce pollution or toxic waste that is hazardous for ten thousand years.
That isn't true, most renewable energy sources, eg, solar panels [0], produce waste that will be toxic waste that will be hazardous for tens of thousands of years. Lead and cadmium don't even decay in practical terms, even after 10s of thousands of years.