The problem is that any environmental strategy based on halting human progress is doomed to fail. The simple fact is that we aren't going to go back to some earlier form of mass transit on routes that are currently served by jets - unless a better technology is developed.

"Better technology" can include a variety of things: better high-speed rail in some parts of the world, better new aviation technologies, better processes/ATC that enable today's jets to burn less fuel, etc.

These will be some of the biggest new product opportunities of the next couple of decades - environmental innovations that drive progress forward, not backwards.

...But I do agree with you on the offset thing. If it drives charitable donations, great, but the underlying premise of removing guilt is somewhat hokey.