The way I see it, being mindful of your carbon footprint is just another aspect of "Leave No Trace" expanded on a more world-view level. I originally got into motorcycling because I wasn't able to continue riding bicycles. Part of that equation is fuel consumption: the car that fits my cargo-hauling needs gets 17-24 mpg. My bikes over the years get 47-75 mpg. Several years ago, I learned about the emissions downside and, while it's getting better with Euro-3 and 4 and upcoming 5...it's still something I want to address in my planning. Giving up transportation and riding isn't a reasonable, realistic alternative. I can look for things I can do to balance the scales and minimize my impact. I can't do much, but I do what I can. If nothing else, this thread got my gears turning about the topic and things to incorporate into my trip planning to bring my own values better in line with the things I do (motorcycling and sating my wanderlust) to enjoy the fact that I'm still breathing instead of resenting it.