John Tierney, no friend of the global warming camp, discusses “carbon footprints” this morning in his “Times Select” column (sorry, no free access). Al Gore he says:

He advises you to change your light bulbs, insulate your home, and cut back on driving and air travel. If you must make a trip, he notes helpfully, “buses provide the cheapest and most energy-efficient transportation for long distances.”

And yet,

Fine advice, and it would be even better if he journeyed to his lectures exclusively on Greyhound. But he seems to prefer cars and planes. When you tally up his international travel to inspect melting glaciers and the domestic trips between his homes — one in Washington and another in Nashville, not to mention the family farm in rural Tennessee featured in the movie — you’re looking at a Godzilla-sized carbon footprint.

Tierney doesn’t draw the fallacious conclusion–that Al Gore’s position (we should reduce our carbon footprints) is false. Instead he seems to be suggesting the conclusion, which is not necessarily fallacious, that “Al Gore is a hypocrite.”

We should note that although this is not necessarily fallacious, it isn’t obvious that the evidence above provides good reason to believe that Al Gore is in fact a hypocrite. In fact, Al Gore–much to the chagrin of many environmentalists–has always favored various market solutions to carbon emissions:

Gore and David say they offset their energy usage by sponsoring reductions in greenhouse gases through alternative forms of power and energy conservation (like building wind farms and paying farmers to turn methane into electricity).

But, how does Tierney argue that this isn’t sufficient? By invoking the judgment of a more radical environmentalist position:

Quoting Gandhi — “Be the change you want to see in the world” — Komanoff says his fellow environmentalists should stop offering “get out of purgatory free” cards [carbon offsets] to the rich and instead insist that everyone personally reduce energy use.

So apparently, Gore’s position is not internally hypocritical, though Komanoff disagrees with it. Nonetheless, Tierney thinks that if you want to work to reduce carbon emissions you must accept Komanoff’s positions:

I’m not such a purist myself — I’d let the average person salve his conscience with a carbon indulgence. But I’d hold environmentalist preachers like Gore to higher standards, especially when they’re engaging in unnecessary energy use.

The tu quoque fallacy is an interesting one. If one is too explicit with the fallacy, it isn’t very effective. But subtle forms of it–like Tierney’s here–which assert hypocrisy and therefore suggest that the messenger and the message are somehow compromised are very effective. Most readers of Tierney’s column will probably conclude that because Al Gore is a hypocrite his arguments and prescriptions do not need to be taken seriously.