Monday, December 24, 2012

This is Pretty Funny

From Skeptical Science:

Of course, if kids wouldn't burn the lump of coal they get in their stockings, it'd be a form of sequestration.... Anthracite coal is about 80% carbon by weight, and, according to a recent paper by Hansen et al there is over 10,000 gigatons of carbon in recoverable coal reserves, so if a lump of coal weighs 1/4th kg all we need are about 4 x 1016 bad kids and the coal problem is solved in a single year. (There'd still be enough oil and natural gas to frack up the climate, so maybe that could be given away to bad kids for Easter and Halloween.)


Bob K said...

I learned long ago to always scrutinize Hansen's figures. Both wikipedia and BP say proven reserves of coal of all grades amounts to about 861 gigatons. Looks to me like Hansen is exaggerating.

BP says:
"Proved reserves of coal are generally taken to be those quantities that geological and engineering information
indicates with reasonable certainty can be recovered in the future from known deposits under existing economic and operating conditions."

You talked carbon, but just in case you meant co2.
EIA says:
"Because the atomic weight of carbon is 12 and that of oxygen is 16, the atomic weight of carbon dioxide is 44. Based on that ratio, and assuming complete combustion, 1 pound of carbon combines with 2.667 pounds of oxygen to produce 3.667 pounds of carbon dioxide. For example, coal with a carbon content of 78 percent and a heating value of 14,000 Btu per pound emits about 204.3 pounds of carbon dioxide per million Btu when completely burned.(5) Complete combustion of 1 short ton (2,000 pounds) of this coal will generate about 5,720 pounds (2.86 short tons) of carbon dioxide."

Not even close to 10,000 gigatons.

Dave X said...

Hansen isn't calling the 10kGT proven reserves as Bob K is conflating. In figure P1. Hansen shows two estimates of reserves around 800GT, and a estimate of "potentially recoverable reserves" of < 10,000G tied to a Coal "Resources" of 440,000 EJoule vs "Reserves" of 12,000 Ej in Hansen's "GAC" cite: German Advisory Council on Global Change (GAC), 2011: World in Transition - A Social Contract for Sustainability.: accessed Oct 2011.

Looks to me like Bob K. is confusing "proven reserves" with "potentially recoverable resources", even though Hansen draws a clear distinction in the figure Bob was "scrutinizing". Rather than Hansen exaggerating, I think that Appell's use of "recoverable coal reserves" has confused Bob.