Fossil Fuels, Strange Arithmetic

I'm a member of the American Association for the Advancement of Science (AAAS).  I've been disappointed by AAAS's silence on the issues of hydrocarbon decline.  In one of the email bulletins they send out, they had a link to a panel discussion on energy.  Here are the opening two paragraphs--

Fossil fuels provide about 80% of the world’s energy and, despite dire predictions since the early 20th century, supplies will not run out any time soon, according to speakers at a AAAS discussion on meeting global energy demand.
“Oil is good for 50 years at current consumption rates, [and] could be extended longer as you go to more difficult resources,” said Steven E. Koonin, under secretary for science at the U.S. Department of Energy. “Coal—there are hundreds of years.”

This is an extraordinarily ill-thought out set of statements.


The claim by Steven Koonin that we have 50 years of oil at current consumption rates flies in the face of the DOE's own reports, the physics of oil recovery, and simple arithmetic.  Widely known estimates of proven petroleum reserves range up to 1.34 trillion barrels.  Morgan Downey's Oil 101 is a great readable reference with a chapter on the subject, but DOE's EIA has similar numbers--http://www.eia.doe.gov/emeu/international/reserves.html.  Taking the top-end estimate from EIA's own table and using a daily worldwide oil consumption of 85 million barrels per day, which is a couple of million bpd off current consumption estimates, yields 43 years, not 50.  It's well known that the best recovery methods (such as the Norwegian techniques) only allow for 70% extraction.  So that drops the upper limit to 30 years.  It's also well known that as oil fields age, production starts to decline, despite the best enhancement techniques.  Many people think that several of the big oil fields, like Saudi Arabia's Gwahar, may be nearing the decline phase of the fields' lives.  So the misstatement is twofold.  We don't have anything close to 50 years of oil at current consumption rates and the physics of oil production may not support current consumption rates as mature fields reach their decline phases (as has been happening in the United States since 1970).  And lest one be mislead by the claims of new "supergiant" discoveries, apply the arithmetic of daily consumption.  At 85 million bpd, we consume 31 billion barrels per year.  The discoveries I've heard of in the past year or two are well under one year's worth of new oil.

Relative coal, I think the situation is murkier, but we certainly don't have "hundreds of years".  Using DOE's own EIA information again (http://www.eia.doe.gov/energyexplained/index.cfm?page=coal_reserves ) they project 146 years.  And that's probably optimistic.  While we have vast amounts, the pattern with coal extraction is that it's far more likely than with oil for recoverable amounts to be less than estimated deposit size.  Coal also varies enormously in quality and energy density.  There's evidence that in terms of energy equivalency, U.S. coal production peaked in the late 1990s.  We're extracting more tonnage of lower energy density coal today.  Presumably our consumption will continue to increase, driven by increased demand and decreased energy density.  So we might have under a 100 years of coal.

If this is "candid conversation" (http://cstsp.aaas.org/content.html?contentid=2376) I'd hate to see guarded conversation.