In Gore We Trust?

Derb notes a comment from noted super-earth-climate scientist Al Gore:

"People think about geothermal energy — when they think about it at all — in terms of the hot water bubbling up in some places, but two kilometers or so down in most places there are these incredibly hot rocks, 'cause the interior of the earth is extremely hot, several million degrees, and the crust of the earth is hot …"

[Derb] The geothermal gradient is usually quoted as 25–50 degrees Celsius per mile of depth in normal terrain (not, e.g., in the crater of Kilauea). Two kilometers down, therefore, (that's a mile and a quarter if you're not as science-y as Al) you'll have an average gain of 30–60 degrees — exploitable for things like home heating, though not hot enough to make a nice pot of tea. The temperature at the earth's core, 4,000 miles down, is usually quoted as 5,000 degrees Celsius, though these guys claim it's much less, while some contrarian geophysicists have posted claims up to 9,000 degrees. The temperature at the surface of the Sun is around 6,000 degrees Celsius, while at the center, where nuclear fusion is going on bigtime, things get up over 10 million degrees.

If the temperature anywhere inside the earth was "several million degrees," we'd be a star.

Steyn follows up:

[Al Gores's] entire, highly lucrative shtick rests on the proposition that a one-degree increase in surface temperature in the course of a century imperils not merely the poor old polar bear, not merely the planet itself, but is "altering the balance of energy between our planet and the rest of the universe". But he's so insouciant about "several million degrees" boiling away a couple of miles under his loafers that he can't even be bothered getting it right to within three figures.

It makes you wonder whether even he believes any of this stuff.

The question that I have, not having seen the video, is whether he tossed off that number as a joke that no one got, or whether he really doesn't know or care. I do know this - he's fond of quoting Upton Sinclair's line that "it's difficult to get a man to understand something when his salary depends on his not understanding it." Well, what understandings and not understandings does Al Gore's enormous income depend on? If every scientist in the world decided today that CO₂ was not a problem, would Al Gore understand it?