On 27 Oct, 11:40, "Dave Liquorice"
wrote:

Except they wern't, their log fires were not releasing fossil carbon.
Now if they had found some black rocks and also discovered they
burn't well that would be a different matter.

Black rocks don't burn well, which is why coal wasn't seriously used
or mined until the Tudor period. You need to have a fireplace and
fairly well-designed chimney to burn coal. Even the first steam
locomotives couldn't burn coal, they had to use coke.

Our use of coal for heat and power really is a very modern invention:
150 years for widepsread power, 100 for electricity. Be afraid. We
broke this place, and we did it very quickly.