Chuck - true. (But my argument on what is essential is based on he cost of it - not the environmental impact)
However if oil gets to $150/barrel it will be more than a billion out of work. The sharemarket will have started to disintegrate.... in fact its such a doomsday scenario I dont really want to think about it. (I am not alone - none of the Western governments want to talk about it either)
As far as the environmental impact of air travel is concerned, any reduction in emissions would be voluntary along the lines of a Kyoto type protocol. Now with China due to receive 1600+ new airliners, I wonder if they will be signing up? And if they don't I wonder how voluntary the other signatory nations would be?
The question is rhetorical of course.
A lot of Asia stopped caring about air quality a long time ago anyway.
Whilst I lean towards the David Suzuki view on the worlds environment - I am not convinced that Global Warming is a fact - (I noted the not very recent public announcement that 2005 was no longer the hottest year - it has been renounced and 1998 is still in front). The data simply is not good enough (the error of margin is in excess of the trend). Nonetheless - anyone can see that continuously pumping all that crap into the atmosphere can't be sustainable.