Jim Hansen himself has addressed this. Even with slightly generous estimates of remaining oil and gas reserves, the total level of global warming will be bad assuming we use them all up, but not catastrophic.

The really big problem is coal. We DO have enough of it to do tremendous damage (push natural geological/biological feedforwards into a big acceleration), and it looks like we are exactly on track to do so.

The back-to-the-future substitution of coal for depleting oil and gas will accelerate. That's worse even per joule/BTU of raw combustion energy because there's no hydrogen in coal, unlike oil and gas---all the energy comes from oxidization of carbon, resulting in greenhouse emissions.

And then there's the extra energy inefficiency of coal-to-liquids, coal-to-gas etc, requiring additional primary energy to get the useful end product to substitute for gas and oil.

There is hydrogen in coal, just not as much as in oil and NG.

I didn't know that. I assumed it was mostly just plain C.

What is the %age, or more relevantly, what is fraction of energy released which comes from hydrogen combustion in CH4 (presumably the maximum) typical gasoline or petroleum, and coal?