David Rutledge Sees Far Less Coal Remaining

Projections of future coal burning maybe excessively optimistic or pessimistic (depending on your point of view) because the amount recoverable from the ground might be far less than governments project.

David Rutledge, a professor of engineering at Caltech, estimates economically recoverable coal reserves at 400 billion tons worldwide. By comparison, governments claim 850 billion to 998 billion tons of recoverable coal.

Rutledge presented this analysis at the annual meeting of the American Geological Union . He has also made this argument previously. Sounds like he's done more number crunching since the previous report.

If Rutledge is right then people fighting global warming are fighting the wrong battle. CO2 emissions are going to peak because of geological limitations.

The figure is substantially lower than the ones used in assessments by the Intergovernmental Panel on Climate Change (IPCC) to gauge possible future emissions scenarios. "This is a radically different number from what is conventionally assumed," said Professor David Rutledge from the California Institute of Technology, who led the analysis. "The IPCC assumes that about five times as much coal is available for burning."

I am more certain about the coming of Peak Oil than I am about Peak Coal. Oil fields appear to have attracted a lot more study.

Rutledge says governments over-predict coal reserves.

"The record of geological estimates made by governments for their fossil fuel estimates is really horrible," Rutledge said during a press conference at the American Geological Union annual meeting. "And the estimates tend to be quite high. They over-predict future coal production." More specifically, Rutledge says that big surveys of natural resources underestimate the difficulty and expense of getting to the coal reserves of the world. And that's assuming that the countries have at least tried to offer a real estimate to the international community. China, for example, has only submitted two estimates of its coal reserves to the World Energy Council  and they were wildly different.

We need lots more nuclear reactors and wind turbines. We also need better batteries for electric cars and genetic engineering of microorganisms for practical biomass energy.