I would conclude therefore, that if we burn all the coal that was then laid
down, we can expect a global temperature rise of perhaps 5 to 10° C,
suitable for the living organisms of the early or middle Carboniferous, but not
necessarily birds, mammals, or even dinosaurs.
It would be catastrophic, because we are doing it more than a hundred thousand
times faster than the Carboniferous change.
But Monte Hieb argues that, since there is not a strong correlation in the graph
between carbon dioxide concentration and temperature over the longer period
shown, the present global warming hypothesis (which would put West
Virginia's coal industry out of business) must be flawed.
I think that he is ignoring the fact that methane is an even stronger greenhouse
gas than carbon dioxide, and that the discrepancies might be due to variations
in methane concentration.
The sudden peak in temperature at the Permian/Triassic boundary coincides with a
mass extinction. which could have caused a sudden increase
in the activity of methanogenic bacteria.
Such bacteria decompose dead organic material in anoxic conditions like
submerged sediments.
They are responsible (by also producing sulfur and ammonia compounds) for the
stink of wet, inadequately turned (and therefore relatively anoxic) compost
heaps.
Or it might have been rapid decomposition of methane clathrate
hydrates.