Which is best for the environment: driving or flying?

October 12, 2007 10:56 AM

Is it better for the environment to drive or fly a long distance?

I'm currently in Baton Rouge, LA and plan on returning to Ottawa, Ontario, Canada for a couple of weeks over Christmas and I'm wondering if driving or flying would be better in terms of global warming and other environmental impacts. If I fly I would use a commercial carrier and it would involve at least two hops as there are no direct flights. If I drive I would use our 2001 automatic transmission Toyota Corolla and spend a night or two in a motel. I would be the only person in the car.

I was under the impression that driving was something like 30x better in part because flying deposits pollutants directly into the atmosphere but I just heard something on the NPR Environment podcast cites thegreenguide.com as saying driving is 2x worse than flying. I couldn't find anything on their site to that effect however.

So which is best? Flying or driving? I realize that the train is probably best and I may end up doing that.

posted by JPDD to travel & transportation (16 answers total)

Well, if you're thinking of a single, one-off trip, the planes you'd be taking would be flying anyway, and the seat you'll occupy would otherwise probably have been empty. The weight you add to the plane is pretty much nothing, so your personal pollution will be next to zero.

Obviously, if you apply this to a larger group of people, it gets much more complex (extra flights etc.), but the way you've got it here sounds like the flight is better by far.
posted by pocams at 11:05 AM on October 12, 2007

The planes will be polluting whether or not you are on them. The car, on the other hand, will only be polluting if you are driving it.

To fully assuage any guilt you might have over visiting family and friends over the holidays... you could always purchase carbon credits.
posted by wg at 11:08 AM on October 12, 2007

From here: "On a New York-to-Denver flight, a commercial jet would generate 840 to 1,660 pounds of carbon dioxide per passenger. That's about what an SUV generates in a month."
posted by smackfu at 11:11 AM on October 12, 2007

Foolish me... that link seems to be Australian. Here is a US based site, if you're really interested.
posted by wg at 11:14 AM on October 12, 2007

Re New York to Denver; it seems gasoline produces 8.8 kg / 19.4 lb of CO2 per gallon burned. If New York to Denver is 1778 miles (Google Maps), and your 2001 Corolla is getting an ideal 36 MPG (highway), you'll burn about 50 gallons of gas, generating 970 pounds of CO2. You're still better off on a fully-loaded plane, especially in a car less efficient than yours.

It sounds like the plane-car tradeoff really depends on how many people you can pack into the plane, so I'd say it's a further reason to fly - you're offsetting the fuel consumption of all the other passengers, too.
posted by pocams at 11:21 AM on October 12, 2007

er, especially versus a car less efficient than yours. Taking a plane in your car is going to incur a major fuel efficiency hit.
posted by pocams at 11:22 AM on October 12, 2007

The plane you would be taking would not necessarily be flying anyway; airlines cancel flights all the time (or merge them) because they can't fill enough seats IIRC.

On top of that, by flying, you are ensuring that the flight in question remains profitable & therefore the airline will continue to schedule it; sure, not flying yourself probably won't make much difference, but if lots of people decide not to fly then it will make a difference. This is much the same as the voting paradox so beloved of economists...
posted by pharm at 11:23 AM on October 12, 2007 [1 favorite]

Re: smackfu, on an individual level, the plane is still going to take off, regardless of whether the OP is on it. The question seems to hinge largely on what sort of a group you're looking at. It's paradoxical that way; on an individual level it produces less carbon to fly, perhaps on a humanity-wide level, it produces less carbon to drive, or to take a train, for that matter.
posted by craven_morhead at 11:25 AM on October 12, 2007

Here's some more detailed info on the effects of flying vs. driving.
posted by bassjump at 11:30 AM on October 12, 2007

The per-person per-mile carbon emissions of driving and flying are roughly comparable, as bassjump's link says.

However, there is a big difference in where the carbon is emitted. Carbon dioxide emitted at ground level takes about 100 years to get to the upper atmosphere where it is most effective as a greenhouse gas, but carbon dioxide emitted from planes can start warming up the planet right away. [Source: recent New Yorker article on Virgin Atlantic.]
posted by medusa at 1:31 PM on October 12, 2007

It sounds like the plane-car tradeoff really depends on how many people you can pack into the plane, so I'd say it's a further reason to fly - you're offsetting the fuel consumption of all the other passengers, too.

I just wanted to chime in that this logic doesn't pan out. Lowering the average does not necessarily lower the sum and the atmosphere doesn't know how many people are polluting, just the sum total of the pollution.
posted by Skwirl at 1:45 PM on October 12, 2007

I have seen a lot of these calculations done, and to tell you the truth it is always the train that comes out ahead of the game. if you can find a way to take the train home you will be doing your best.
posted by stilgar at 1:45 PM on October 12, 2007

this is a bit like the "my vote doesn't matter" conundrum. of course it doesn't, but if everyone thought that way, there'd be no votes. somebody's vote matters.

by flying, you contribute to the demand which increases the supply. that means more flights. true, your one-off flight won't make a difference, but that logic doesn't hold on the larger scale.
posted by klanawa at 8:56 PM on October 12, 2007

Occupying a seat on a flight does makes an immediate difference in the pollution caused by that flight, even if it is seat that would otherwise have gone empty. Each pound of payload requires additional fuel to move it across the country.
posted by Good Brain at 11:03 PM on October 12, 2007

Thanks for the answers (although I'm still a bit confused) - I just found the NPR story I originally referenced.
posted by JPDD at 1:04 PM on October 15, 2007

Oh and there's a new Ask Umbra Article about this.
posted by JPDD at 11:08 AM on October 19, 2007