What about the nights you spend in hotels while driving across the country? Remember they've got to clean all your linen after you leave. You've got to factor that environmental cost in. Instead of one hotel for a week (at your destination) -- you're staying in 3 or 4 hotels there and back over the same period (or, indeed, slightly longer so you still get to have a vacation when you get there!) with all those extra environmental hits added in.

Then, of course, there's the parking fees at the hotel at your destination (either explicit, or "hidden" in the room cost). That's $20+ a night. Staying for a week is gonna bump those "drive" figures some. Plus, of course, having your car available is gonna mean you plan your holiday around it, rather than more sensibly enjoying public transport in your holiday city.

And then, of course, there's the drive home. Nothing kills the relaxation of a holiday more than battling traffic for a couple of days at the end of your trip. Not to mention the fact that by exposing yourself to tens of hours "in car" you are increasing the already high chance of being in an auto accident.

As everyone knows, the most dangerous part of any commercial airline flight is the drive to and from the airport, so, to be fair, we need to factor in the environmental cost of "A Holidaying Family Was Killed Earlier Today In A Tragic Highway Accident".

Or do we put that down as a "net environmental gain"?! I'm only being very slightly facetious.

Actually, the solution for the original question is extraordinarily obvious (though, admittedly, requires extraordinary political will):

Simply legislate to factor in the environmental externalities of flying in terms of a "green tax". And of course, do the same to cars. And trains.

Then you sit back and do the simple thing of letting people decide on the time/cost/safety/enjoyment axis all on their own, rather than the "solution" this article chooses, which is making highly dubious and risible "back of the envelope" calculations which confuse rather than elucidate.

Looking into Putin's eyes and seeing "K, G, B". That's actually pretty funny!

Looking into George H W Bush's eyes, of course, one sees "C, I, A".

Let's play some more! Looking into Dubya's eyes? "A, W, O, L," naturally.

And McSame? "M, I, A" is probably a bit cruel. I personally see "A, F, K". It's one of those "internet chat" abbreviations that means "Away From Keyboard".

The lights are on, in other words, but no-one's home.

1,000 kgs = 1 tonne.

Or one "metric ton" to use the US neologism.

Of course, 1 tonne is 2,204 lbs, which is close enough to 1 ton (either short or long, US or UK) for government work.

It would be nice, though, in a basically "facts a figures" article (not that I agree with all its conclusions, see previous letter) to get these simple things right.

*whistles* Hey editors!

Check carefully when he means one way and round trip...

And the reason that "checking carefully" is needed? Because this article desperately needs editing for clarity -- a point several people are making above.

But I think his main point about car versus plane is correct, for the conditions he assumed.

But the conditions he assumes are idiotically simplistic. As is multiplying the plane figures by three because there are three people. If you were chartering a plane to take three people -- and only three -- across the country, and comparing that to driving your own car with three for the same journey, that sort of "passenger mile" comparison would make sense. Again, as pointed out above.

Most of the comments here are pathetic. Read, research, think!

Actually, most of the comments here reflect real problems with the article. Some of them aren't much more articulate than the article, but then the authors are not Salon columnists (ahem!).

And here's 5 cents worth of free advice: beware of the old "everyone's an idiot but meeeee!" post, it rather communicates the opposite message, don't you think?

[the article] is correct in its main point.

No, it is not.

Do a Google search on "fly or drive environment". Or pick relevant words of your choice.

I mean, come on. This stuff is just basic.

There are articles on how such a choice is apples/oranges. There are articles saying "car". There are articles saying "plane". There are articles saying "stay home".

But compared to almost all of them, the assumptions made by this particular article are facile and idiotic. Not to mention badly written, presented, and edited.

Did you know that in the year after 9/11, lots of people chose "drive" over "fly"? Because they were scared. The maths is now in. 1,595 extra people died on the roads because of that decision. Look it up. The relevant paper was written by Gerd Gigerenzer. They weren't killed by terrorists, or global warming, or bad driving. They were killed by incorrectly identifying risks, and making fear-based decisions on that basis.

All of which is to say that an article purporting to talk about the "ecology" of "fly or drive" which doesn't mention safety -- to simply limit myself to one of the many "problems" with this article -- is an article that's facile and idiotic on its face.

Oh, and I was wrong about one thing: "everyone's crazy but meee!" is apparently _exactly_ what's required to get an editor star around here...