Airline food for thought

There was a thought-provoking article in last weekend's Observer about just how guilty we should feel about our air travel in these days of global warming hysteria.
While claims from the pilots' union Balpa that planes are greener than trains and Airbus' promise "to save the world, one A380 at a time" should be treated with the scepticiem they deserve, it's by no means clear just how damaging air travel actually is. As with all global warming discussions, it very much depends on the assumptions you make and the position you start from.
For one thing, according to the influential Stern Report, air travel only accounts for around 1.7% of global greenhouse gas emissions (compared to 24% from power generation, 18% from deforestation and 12% from shipping, rail and road transportation).
The article further argues that the positive benefits of eco-tourism to employment and economies in third world countries (over and above the other negatives which eco-tourism admittedly brings), more than justifies the additional carbon footprint. This is comparing apples with oranges, but food for thought nevertheless.
What the article does best, though, is to show how statistics can be bent to prove opposite hypotheses, how drastically different assumptions can skew the resulting conclusions, and how dangerous quoting out of context can be.
The article concludes, sensibly enough, that in the absence of other categorical imperatives, we should:

"choose airlines with greener, newer fleets, and thus encourage plane makers to prioritise environmental performance; to travel to destinations that help local communities rather than destroy them; to take the train where possible; to reduce carbon emissions at home; and, above all, lobby politicians to tackle deforestation and to switch to green forms of energy."