Okay, yes, I'm exaggerating a bit. And there were some very sensible things said by drplokta, such as the carbon impact of a LA-London flight being about GB£19 (about US$37), so why not add that (in things that offset carbon usage) to the cost of such trips. That's not a lot of money, I think.
I'm not about to stop traveling anytime soon. Now I'd be happy to travel more by train (probably a less carbon-consuming way that air or automobile) if it were possible for me to do so, but I'm not going to stay home whinging about how Evil it is to travel.