Reading through this thread one thing becomes clear: there is less certainty about coal reserves than about either PO or ACC, which is fascinating. I'd have thought coal reserves would be more easily quantified than oil.

The 7 trillion vs. 1.2 trillion spread is pretty wide and worth investigating, but given the uncertainty about coal reserves and the time left to act (Hirsch, et al. 2005), it's an academic question, at best. Decisions about energy and climate will need to be made long before verifiable numbers for coal are ever determined.

We come back to risk assessment. Is it worth the risk that there *aren't* enough coal reserves, that there *isn't* enough CO2 to push us into catastrophic climate changes, that tipping points are happening now... etc?

I don't see how it is.

Besides, what are generations a hundred, two hundred, five hundred years from now supposed to use for energy? Etc.

That is, I think the discussion is moot wrt policy. We have no choice. And if we don't act, we risk it all. Those aren't odds I'm interested in.

Cheers