Oy. I used to think the introduction of hybrid SUVs was generally a good thing — with perhaps even greater potential for saving fuel than hybrid cars. But this New York Times article brings up a point I simply hadn’t considered: Buying a fuel-efficient SUV makes it possible for car companies to sell big gas guzzlers without incurring any penalties under federal CAFE (corporate average fuel economy) standards. From the article:

[E]very Toyota Highlander hybrid S.U.V. begets a hulking Lexus S.U.V., and every Ford Escape — the hybrid S.U.V. that Kermit the Frog hawked during the Super Bowl — makes room for a Lincoln Navigator, which gets all of 12 miles a gallon. Instead of simply saving gas when you buy a hybrid, you’re giving somebody else the right to use it.

This is vexing, to say the least.But it also underscores a point that’s hard to overstress: When it comes to saving energy, a broken system can trump individual virtue. That is, any time a conscientious and enlightened consumer decides to do something selfless, our energy system pushes back a bit. Use a little less gas, and the oil market responds by letting someone else tank up a little more cheaply. Buy an efficient vehicle, and you make room under CAFE standards for someone else to buy a wheeled behemoth. And so it goes.

Of course, I don’t mean to suggest that it’s completely futile to make efficient buys — not by a long shot. But particularly when it comes to energy, the collective good wrought by environmentally conscious consumers is typically less than one might hope. To me, this underscores a simple point: Changing your own behavior is a good idea, but changing the system is far, far more important.