In a Mother Jones magazine essay, Over a Barrel, energy expert Paul Roberts, considering the near-impossibility of creating a sustainable-energy world in any reasonable span of time based only on market forces, speaks of an American "wall of energy denial" and of American consumers who "still share the [Bush] administration's energy obliviousness." He adds that "U.S. gasoline consumption continues to rise, despite high oil prices." Well, exactly. And we're talking about something closer to the Great Wall of China than a picket fence. Those fortifications of denial start with oil and wend their way across a rather impressive terrain of future troubles, well patrolled by an army of Hummers and SUVs. But even those Americans who don't care to -- and still don't have to -- peer over the wall already essentially know what's on the other side. That's the nature of denial. After all, you can't deny what you don't, at heart, know to be so.