I hadn't realized this, but apparently the Democratic National Convention's planners are making all kinds of moves to make it the "most sustainable" convention ever, including a search for the elusive carbon neutrality. I think individuals who aim for that kind of objective in their personal lives are acting out of laudable motives, but to me it's actually counterproductive for a political organization to be doing this.
The public policy argument made by liberals is that the United States ought to reduce its carbon emissions, and that this can be accomplished either by a cap/permit scheme or a carbon tax scheme. Either would have the impact of raising the price of carbon emissions, with that added cost transmitted up and down the economic conveyor belt, leaving each consumer free to make each individual choice and tradeoff based on considerations of price and quality. In the end, carbon emissions will fall and climate change will be mitigated. Engaging in the laborious (indeed, impossible) task of calculating the aggregate carbon footprint of each and every individual activity you engage in isn't part of the agenda on any level.
The individual carbon footprint of any particular activity under the current policy regime just isn't relevant -- the point is that the current policy regime is bad and needs to be changed. When you see the Democratic Party aiming for a carbon neutral convention, it does much less to improve the environment than it does to define environmentalism in terms of an unrealistic standard of behavior that few individuals will reach, while rending huge swathes of the progressive community vulnerable to spurious charges of hypocrisy from the right.
Photo by Flickr user Clownfish used under a Creative Commons license