Thanks for linking the article. I came away with a few questions. In the first paragraph the author talks about driving (carpooling), flying and then a boat ride to get to her destination. The flying is deemed environmentally the worst - what was next worse, the driving or the boat ride? Where would a train ride fit in this hierarchy? How much worse is one vs. the other?
Unless you use the sailboat, bicycle or walk it seems to me that cutting back on travel altogether is environmentally sound thing to do, especially if the driving or boat travel are only incrementally better than air travel.
My final thought is that, environmental concerns aside, the TSA and the tiny, cramped coach class airline seats have done a lot to lessen my enthusiasm for air travel.