I skimmed this article pretty quickly, but ol' Pablo seems to think there'll be only three people on the airplane, as there are in the Toyota Corolla. Most jets carry from about seventy to several hundred people (have to Ask the Pilot about that), so would replace dozens of cars. Wouldn't this affect the calculations substantially? His idea of a "medium-size" engine (1.4-2.1 liters) also seems awfully small, though maybe not for a Corolla.

On the other hand, you don't have to go through TSA if you travel by car -- yet.

First, a technical one: I seem to recall reading that high-altitude contrails (water vapor exhaust from the engines) actually has an overall cooling effect on ground below -- for example, in the days after Sept. 11, 2001, temperatures were higher than before. According to this article from the Chicago Tribune, "During the three-day grounding, the diurnal temperature increased by 3 to 5 degrees, the only time it has made such a significant change in the last 30 years..." So there might be more emissions from flying, but an overall cooling effect.

Secondly, one might take a different approach to calculating your effect of your choices. If you choose to fly, that makes essentially no difference to the airline; they're not going to schedule or cancel flights based on what you do. Your personal choice to fly might affect prices for other people by a few dollars (by slightly changing the balance of supply and demand), but it won't much affect how much fuel is burned. There will be a slight increase in fuel use due to increased weight, but I don't think Pablo calculated it this way (not that I'm knowledgeable enough to do this).

If you choose to drive instead of fly, that will definitely create 2 tons of CO2 emissions that wouldn't be created if you flew. So maybe flying isn't so bad.

Now, I do realize that if lots of people choose to drive instead of fly, that airlines would cut flights and emissions would drop. This is a case of the tragedy of the commons, and it's always a hard issue to deal with.

I think your calculations on gasoline for the Toyota must be for a round trip. 3100 miles divided by 30 mpg is not 207 gallons,

He explicitly says per passenger for the airline figures.

What really ticks me off is environmental people saying we just have to make a few simple changes. First of all, if you expect me to give up a few hours of flying for several days of driving, it is not a little thing. Staying in campgrounds? This would require hauling a trailer. You can't seriously think people are going to sleep all that time in tents. More likely, for most people, it would involve staying in a motel, which is much more expensive than plane fare. And as far as just taking time off and staying home, I've done that and unless you have something really interesting going on, it doesn't feel like much of a vacation. You don't end up feeling refreshed, more likely depressed.

Ok, I know this stuff is important, but just don't say it will be some simple changes. It's going to take a lot of sacrifice to stop global warming.

Don't know the answer myself, but it is my understanding that trains are highly efficient at getting stuff from one place to another (low rolling resistance from metal wheels, excellent aerodynamics from a long, slim profile, and hybrid Deisel/Electric propulsion).

So now I'm supposed to believe a 30Mpg Camry is more efficient?

I'm seriously doubtful. I've always been of the opinion that it would make good sense for Amtrak to offer trips between the Coasts and other points of interest that included hauling the passengers' autos along, because of the efficiency of rail transport.

Have I been so wrong? I'm going to take some convincing.

How about some intangibles, here?

A prior respondent complained about the extra time to drive. Fair enough, but why not make the trip itself part of the experience?

Take a road trip- take your time. Plan to see some things along the way, but also take time for discovery by setting aside some drive-time on old US routes and local roads, instead of the Interstates.

Find a little town somwhere and meet some amazing people while you're having lunch. These will be people who, by and large, have to work for a living and love their children at least as much as you do. You might be surprised to learn just how many folks are way more on top of things than you might have given them credit for.

Go in with an open mind, and no 'tude. Look people in the eye, and treat them as equals when you talk to them. You might learn something, and have fun doing it. What say?

Happy Motoring!

it's pretty out there

but yeah, there's a pretty big difference between several days of driving and a 6 hr flight...

@Felix -- yes, exactly. But are those "per passenger" numbers really calculated based on the addition of a single person to the plane, or are they assuming a certain percentage of a full flight and counting the entire flight's cost? Without knowing what the number is based on or the actual per-flight number, it's impossible to make a meaningful comparision.

Also, I just want to add that it's pathetic that as a country we've let our rail situation come to the shambles it is, because without even having any numbers I'm quite certain that'd be the winner in an idealized world.

Making the journey "part of the vacation" sort of assumes a number of things. Most importantly that you are not traveling to see family and that you have a large amount of time to take off.

If you wanted to take a week off and drive cross country to take the kids see Grandma and Grandpa, you have about seven days to work with (assuming you don't want to pull in sunday at midnight and then go to work the next morning.) Even without "making the journey part of the trip," a trip from where I live in LA to where my parents live in Texas takes two days (22 hours driving time - and I'm sure it's a very different trip with children than when I used to do it in school, blowing through west texas at 100mph) each way. So if I took a week off of work to take my (not yet existent but who knows what will be in a few years) family to see my parents I have the following choices.

Spend two days driving each way and spend three days in Texas with my parents.

Spend three days each way stopping a bit making it a fun drive trip; then spend a total of one day with my parents.

Fly, and spend every day with my parents.

Even if I were not traveling for family reasons, I hardly see the point of going anywhere if I am not going to spend more time there than I would spend traveling no matter how enjoyable that travel is. As long as most people's vacations have to take place within the context of a week off from work, it makes cross country travel via car pretty much a no go.

Regional travel of course is a different story. A trip to Vegas or San Francisco or maybe even Portland could make sense as a drive trip.

I think someone needs to figure out what percentage of recreation travel actually is to a recreational destination, and what percentage is for visiting family.