wrote:

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.

Wake up! Pablo multiplies the numbers for passenger mile for the plane by three to get the total amount of carbon dioxide for three passengers so he can compare this with the total from the car (which also is carrying three people).

I do not think this article is hard to understand; it is correct in its main point. It is perfectly justified to point out that commenters should think before writing. And you are one who should think extra hard!

Most people do not think quantitatively with much skill, but this set of comments is far worse than I would have expected.

wrote: Yes. That's exactly the problem (or one of them, anyway). As I and others have repeatedly pointed out, evaluation of actual carbon-emission scenarios does not work this way.

A jet flies from A to B, some number of miles. It produces a certain amount of carbon dioxide. Divide by the number of miles and the number of passengers. You get carbon dioxide per passenger mile. A more complicated process can give an industry average, and you can get different numbers for short and long flights, etc. But the concept is pretty simple.

You can use this rate to compute the carbon dixide emissions attributable to three persons flying from A to B. You can also compute the amount of carbon dioxide produced by three people in a Toyota driving from A to B. This is pretty much what Pablo did. It is not perfectly accurate, but it is pretty good.

In your original rant from yesterday you listed many factors; these are taken into account, at least to some reasonable level of accuracy, in the process I described in the two previous paragraphs. If that rant was indeed a serious letter, I am sorry to have misinterpreted it. But when you write things like this:

In point of fact, a large airliner spends most of its energy getting itself aloft. The passengers are a relatively small part of the effort involved, simply due to the sheer size of the aircraft to begin with.

you have to realize that the irrelevance of this statement the concept of CO2 per passenger mile certainly looks like humor.

wrote:

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...

The article was about comparing carbon emissions, not safety. This was Pablo's interpretation of the question he was asked. Seems like a reasonable interpretation.

I did not say anything about the state of mind of the commenters, just the quality of the comments. Projecting a little?

wrote:

Trying to apply passenger-mile emissions figures to a microanalysis of a single airline passenger's actual contribution to carbon emissions is simply unsupportable.

But that is not what Pablo has done. The family under discussion is a typical case, not Raul Alonso, his wife Eva Martinez, and child Roberto traveling from Miami to Chicago on June 7, 2008. The whole purpose of such statistical rates is so that you can make comparisons like Pablo has done.

And wrote this:

What you (and Paster) are doing is the logical cousin of saying that if the chance of a coin coming up heads is 50%, and the last 3 flips have come up tails, then it's certain to be heads this time.

Baloney! Pablo's article deals with averages in a correct, if simplified, manner. It does not try to draw incorrect specific conclusions from previous specific information and associated statistics. If you really think it does, then you need to re-learn probability theory and statistics. I am still having trouble believing that you are serious, but if so, you are making a mistake.

and fun to read. It brings up the old question again: why are they seeking pardon if they did not break the law? Just a precaution, right? A kind of "get out of jail free" card to protect themselves from those nasty libruls. You never know when someone will accuse you, right out the blue, of having given their private information to the government. And it is so easy for it to happen by mistake. But those commies will show no mercy.

wrote:

The math says she, on the micro level, can reduce her carbon the most by not driving. Unless she's planning to start a campaign to reduce emissions, the macro level is irrelevant.

If one person makes a decision not to drive, then many do, and the demand for the mass transit is reduced. The "micro level" is an illusion.

Talk about unjustified optimism.