[asmosoinio]

That's per passager mile, right?

For the comparison parent post is making - leisure travel - I think there's a big difference in that flying enables much larger distances, thus much more emissions.

You can easily fly 1000 miles each way for a weekend trip. Not as easily with a car, the travel tends to be much shorter.

[iancmceachern]

And also doesn't take into account economy of scale, a family of 4 has 4x the emissions in the plane example, same as 1 person in the car example. So if you do the math as a family of 4 it really changes things.