In addition to the possibility of distraction and moral license mentioned in another post, there is a problem mentioned in the parent post itself: being anythin

In addition to the possibility of distraction and moral license mentioned in another post, there is a problem mentioned in the parent post itself: being anything less than immaculate in your reasoning gives detractors more fodder. Imagine: we go all-in on villifying air travel. It works! Everyone is shamed into commuting by train. Huge sacrifice, people don't see their extended families anymore. We do it to save the planet! Uh-oh: the needle has barely moved. "Well, yeah, it was only 2%, but it wasn't mutually exclusive with other stuff! No harm no foul, right?" Now you've lost credibility when it matters. This hyperbole hopefully illustrates the more subtle reality: if you make even the slightest mistake there is a lot of Money ready to trip you up. Don't be caught of guard; stay on point, hit where it hurts: carbon tax. The rest will follow. (By all means reduce air travel, keep talking about it, don't get me wrong. But never make it out to be more than it is, is my point. 2% is just that, and maybe it's worth it to us as a species to keep doing this, while cutting back more in other areas. That's the beauty of a carbon tax: it will allow people to decide just how important that 2% is to people, personally. Nobody knows that in advance, that's the power of markets.)