True or False: SUVs are Greener Than Scooters

Scooters waiting to be rented (Digital Photography).

SUVs are bad, etc. etc.: this much we know. But could downgrading to a sleek scooter be worse for the environment than an SUV? This was a question posed to the Chicago Reader's Straight Dope column, on the basis that a two-stroke engine pollutes more in an hour than a car does all week. So should the smug Vespa-riding friend of the author give up and get a 4Runner? Not so fast.

Scooters do pollute more than cars - If they have a two-stroke engine. Straight Dope's Cecil Adams says they can legally emit "5.7 times more CO than cars, nearly 24 times more unburned hydrocarbons, and infinitely more NOx [Nitrogen oxides]—and real-world testing suggests they do run pretty dirty."

That's not the whole story, though. Two-stroke engines are not prevalent in America anymore, but are still used in other parts of the world. American scooters have four-stroke engines, which run much cleaner. While a two-stroke scooter may pollute more than an SUV, that still doesn't mean SUV drivers are greener, and here's why:

• The production of SUVs consumes more resources
• An SUV contributes twice as much to global warming as a scooter
• It takes less energy to operate a scooter
• They are less burdensome on our roads

Even better for the planet: an electric scooter.

While a two-stroke scooter may pollute more, it's a trade-off, says Adams:

So what’s the takeaway here? Scooters emit more pollution, but they help the planet overall by adding less to greenhouse gas buildup. Or, to put the matter in more downbeat terms, your choice is between choking in the city or dying from mass climate change.

Upbeat. And now, the score between smug scooter drivers and wanton SUV drivers is settled.

Clarification 4/13/09: The Chicago Reader article cited in this blog overstated the prevalence of two-stroke engines in scooters. Four-stroke engines, which are more prevalent, run cleaner.