One does not have to like monetary economics but cannot ignore it. For example, different sources of electricity produce a BTU at very different prices. Motor fuel is uniquely valuable because it is transportable, not because of how many BTUs is has. And electricity is a significant component of converting all sorts of non-conventional sources to motor fuel. But I feel this is exactly what the IPCC getting at by pointing out that the amount of fossil fuels overall is not likely to be limiting.
Simple observation counts for nothing in policy processes.
Decision makers expect to be swayed by powerful scientific arguments. And, short of an environmental revolution, conventional policy processes are the only way to changing anything.