Gary Snyder, the great beat poet, writer/teacher and deep ecologist once mentioned that it would be a good thing for us to do the following for the natural world: stay home. Of course Gary travels widely! Of course it's not that simple. I don't really think the issue is so much one of details as it is of a general emphasis. Up until now, we seldom considered these things at all. I would just like to see people really thinking deeply about what they do. That would be a great start. I will still travel, but I hope what changes for me is a serious consideration of the options when I do travel, asking myself if there is a good reason to do so, and if there are alternatives. If there is a good reason to go somewhere, and the alternatives don't exist or are out of reach (like me buying a new hybrid: right now I just can't do it) then I may still go ahead. But sometimes I'll discern that there is no good reason to go, or that there IS an alternative. Right now, I'm studying "passenger-miles-per-gallon" (better with more people in any vehicle, not so good in an aircraft, best in modern railway types like Colorado Rail Car's recent designs) to determine the best way to take people on natural-history trips. So far, the most-efficient and still fairly practical option seems to be a 15-passenger van or small bus. After this year, I won't lead any "car caravan" type trips - I feel it is just too wasteful. And all along the way, I am realizing that I can't "tell other people what to do". We all can have a dialogue, we can discuss, we can debate...and in the end, only so many even pay attention. And then we ourselves just do the best we can. And then, I hope we'll go back again to that earlier consideration: deep thinking about what we're doing. That will be light years' ahead of what we've been doing so far.
For more on this topic and its intersection with birding and natural history, read Mike McDowell's recent excellent discussion here and Laura Erickson's post here.