According to a commenter on my previous post
, the only scenario in the current IPCC projections that results in temperature increasing by more than 2°C from now to the end of the century assumes a total consumption of coal considerably greater than the total amount believed to be recoverable. I do not know if he is correct—he links to a presentation
on estimating ultimate coal production.
Thinking about that claim, it occurred to me that there are (at least) two arguments for shifting from fossil fuels to recyclables, that they tend, in my experience, to be supported by the same people, and that they cut in opposite directions—the stronger one is, the weaker the other.
One argument is that fossil fuels are a depletable resource that we will eventually run out of and that we should therefor be switching to non-depletable resources such as solar, wind and water. The peak oil version of this argument has been popular for quite a long time, and the same argument applies, in principle, to gas and coal.
The other argument is CAGW—Catastrophic Anthropogenic Global Warming. Burning fossil fuels puts CO2 into the atmosphere which raises global temperatures and, it is argued, the increase in temperature and associated climate effects will have very bad consequences.
As best I can tell, the two arguments tend to be supported by the same people. This makes sense from the point of view of someone who has a conclusion and wants arguments to support it, since both arguments support the same conclusion. It also makes sense if one sees views on such issues as largely determined by ideological allegiance, with liberals and environmentalists tending to believe in problems that require government action to solve, conservatives and libertarians tending to be skeptical.
On the other hand ... . The more limited our supplies of fossil fuels are, the lower the climate effects of burning them all up. If we are going to run out of all of them by, say, 2050, then any global warming projection that depends on our continuing to burn them thereafter is impossible. To put the point differently, the closer to exhaustion we are, the higher the price of fossil fuels will be, ceteris paribus, since anyone who owns a coal mine and expects the price of coal to go up sharply as supplies are depleted has an obvious incentive to postpone production until they do. The logic of that situation was worked out in a classic article by Harold Hotelling more than seventy years ago.
The higher the prices of fossil fuels, the greater the incentive to switch to renewables. If exhaustion is a serious problem, if likely rates of consumption will make fossil fuels much more expensive by, say, mid-century, the CAGW problem will take care of itself without any government action needed.