Articles by Clark Williams-Derry

Increasing numbers are changing the cars they buy based on fuel economy.

From the Christian Science Monitor, evidence that consumers are beginning to think about gas prices as they make new vehicle purchases:

Last month, 49 percent of new-car buyers, the highest level ever, had changed their mind or were thinking strongly about buying a vehicle they would not have considered because of gas prices, according to a survey by Harris Interactive and Kelley Blue Book.

Over the short term, rising gas prices only affect consumption a little bit, because people have only so much flexibility to change their driving habits. Over the long term, though, people start making more fundamental changes -- where they live, what they drive -- can lead to more significant reductions in how much gas they use.

There's still plenty of room for skepticism. Sales of hybrids are surging now, but some industry analysts are predicting that demand will top out, with hybrids commanding a small share of the market. (Some of those skeptics, of course, are from car companies that don't produce hybrids -- so take those predictions for what they're worth.) But then there's this:

Even McManus -- the hybrid cynic-turned-believer -- has serious doubts about how big an impact even a massive surge in hybrid sales will have on reducing America's oil dependence. His analysis, for instance, shows a "rebound effect. For every 1 percent decline in the cost of fuel, Americans drive 1.85 percent more.

That number seems way too high to me, and this lit. review by Todd Litman of the Victoria Transport Policy Institute seems to agree. Still, all else being equal, increased vehicle fuel efficiency does tend to reduce the cost of driving a mile, which in turn increases the number of miles people drive. Which leads to this seeming paradox: in a world of hybrids, we might drive more, but still use less gas.

In other hope-inspiring vehicle news, cleaner diesel vehicles may be on their way.

A new study on diapers finds no difference between cloth and paper

Ok, that's a dumb headline. But the problem itself -- whether to diaper my babies with cloth or disposables -- was one I spent a bit of time agonizing over.

But perhaps I shouldn't have. A new study commissioned by the British Environment Agency (reported on here and here) suggests there's almost no difference between the two, at least in terms of environmental impacts. Which is roughly the same answer that this 1992 study, at the website of our friends at the Institute for Lifecycle Energy Analysis, came to.

The British study made some suggestions for ways that both disposables and cloth diapers could be improved, to reduce their impacts: for people who wash theyir own diapers, that means reducing washing temperature, using efficient washers, and line drying for home-washed cloth diapers. (Which, of course, is good advice for all your washing, not just diapers.)

Buying a Prius has benefits, but don’t forget the costs.

A reader of the Cascadia Scorecard Weblog had this question: What do we think about this piece of advice from the May-June Sierra Club magazine's "Hey Mr. Green" column?

Hey Mr. Green,

What's best for the environment, continuing to drive my perfectly fine 1990 Honda Accord, or trading it in for a new gas-sipping Prius? -- Heath in Los Angeles

Well, Mr. Green hates to say this because you might be bonded to your trusty old Accord, but she burns twice the petrol and wheezes out twice the global-warming gas of a Prius or similar hybrid model. Being a conscientious environmentalist, though, you're also worried about the energy and pollution involved in building a new car -- the equivalent of 1,000 gallons of gas. But by the time the Prius hits 50,000 miles, its energy savings will have made up for its own construction. So unless you drive very little, a new hybrid is the way to go.

That's not necessarily the advice I'd give.

Raising CAFE standards may actually backfire.

It's a rare treat to read a dry, technical report and--almost by accident--learn something surprising, counterintuitive, useful, and (at least to me) genuinely new.

Which is exactly what happened when I read this paper (beware, PDF) by Todd Litman at the Victoria Transportation Policy Institute. The upshot: Raising vehicle fuel-economy standards, which always seemed to me like a good idea, may actually be counterproductive, even if they're truly successful at reducing the amount of gasoline the average vehicle consumes per mile.