See Coyne’s article at:

Dennis Coyne. March 11, 2016. Coal Shock Model. peakoilbarrel.com

[ The IPCC has not invited geologists to estimate fossil reserves, and sides with the “no limits to growth” economists.  The IPCC believes that too expensive or technologically unavailable energy resources will be exponentially available in the future out to 2100 because of magical thinking, not geology, because homo sapiens are so clever we can do anything, regardless of the laws of physics, and that if enough money is printed, anything is possible. 

But if peak oil, peak coal, peak natural gas, and peak electricity have already happened or will soon, then IPCC  projections are far too high, and we ought to be more concerned with reducing our use of fossil fuels, especially oil (the master resource), rather than greenhouse gas emissions.  After all, reducing the use of fuel reduces greenhouse gases. Oh well, we are about to use less fossil fuels regardless, especially once the master resource, oil, declines, since it makes all other resources available via transportation (and specialized mining, agricultural, construction, and other trucks).  Energy efficiency is not a solution, we need to actually reduce the amount of fossil fuels used every year to stay under the depletion curve.  It isn’t clear whether or not our economic system could handle that, since it is based on endless growth. 

Alice Friedemann   www.energyskeptic.com  author of “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer]