Here is something that occurred to me, concerning the
'coal fired' power plant issue.
One of the main objections, aside from the particulate discharge into the air
(containing Mercury),
the coal ash has significant amounts of
Mercury and Arsenic and other heavy metals.

My first thought was, "hey, we have need of and uses for
Mercury and Arsenic et al in industry,
why not treat the coal ash as a resource like a mine and
Find a way to extract all that?"

(keep following my reasoning)
Then I thought;
The plants we have today fix contaminants in the environment into
the wood and vegetable matter as they grow.
Oil was formed by micro organisms in the oceans dying and being laid down.
Coal was formed on land by plant matter, dying and being laid down.

So the coal of today was formed by plants,
Living in an environment where there were
High levels of Mercury and Arsenic and other
Heavy metal pollutants.

Conclusion?

There was an industrial revolution millions of years ago that
Polluted the planet and caused a crash, leading to the formation of our
Present day fossil fuels.