This has long bugged, me but Greg Mankiw's op-ed in today's NYT prompted me to complain about it again. I have no complaint about his actual thesis, which was the basic, obviously correct economics: A carbon tax is a much better way to discourage people from causing so much GHG emission (assuming we want to do that) than is the hodgepodge of often inefficient regulations and incentives -- especially if the tax is offset by tax cuts that are targeted at making the cost impact neutral for the average person. But what bugged me was his musing about what he might personally do to reduce his own emissions.
As is typical for people discussing this, he mentioned driving a more fuel efficient car, adjusting his thermostat, solar panels, and eating locally. To his credit, he avoided mentioning totally useless and counterproductive gestures like recycling. Also to his credit, he actually included one of the three biggest things someone can do, three things that are generally ignored by the typical bourgeois self-congratulatory worriers about climate change. Most important, of course, he was advocating an efficient alternative to hodgepodge and voluntary action that would make the benefits of avoiding particular consumption proportional to the costs of emissions impact of it, solving this problem: With a carbon tax, the costs would be internalized for everything, including those actions that are typically ignored. Thus this screed should be seen as directed at the chattering enviro types, not at Mankiw.
It is pretty clear that there are four changes that matter for reducing the carbon emissions you cause that you can do while still maintaining a basic modern lifestyle: don't fly on airplanes, live in an urban apartment, don't eat meat, and minimize gasoline use. Everything else is just a rounding error. Of course none of these are absolutes -- the closer you are to the minimum the less impact.
The funny thing is, the activists who push this topic -- typically upper class, though not 1%-ers -- tend to mention only the last of these, and then only in terms of what to drive, which is solidly down in fourth place. Why do they conveniently ignore the actions they could personally take that matter a lot more? The most obvious answer is because they want everyone else to make the sacrifices. Their only "sacrifice" is driving a Prius and maybe installing solar panels, which are really visible status symbols for them, points of pride that make them happier, rather than sacrifices. Those actions are kind of like giving up smoking for Lent because you want to quit smoking; a sacrifice is something that makes you worse off, not better. It much more appealing to offer gestures that actually make you happier and reserve the unhappiness for others. So, for example, wealthy climate change activists try to force everyone to pay a lot more for electricity, a cost that they personally can just shrug off or even consider a net gain because it makes them happy, but that is painful for the average American or Canadian suffering that wealth shock (to say nothing of the average Chinese).
Mankiw did not mention living in an urban apartment per se, but he did cite both of its advantages compared to living in a suburban house (as most people I know who chatter about this seem to): You are closer to where you want to be so you drive far less (which matters a lot more than what vehicle you drive, especially if you can avoid having a private car at all) and the space is smaller (though he only mentioned the reduced climate control costs and not the important costs of building the structure itself and cultivating a grass monoculture in space that could be growing naturally).
He did not, however, mention not eating meat or minimizing how much you eat. This action is something that most everyone can make without massively disrupting their lives, unlike the others (move to the city, minimizing transport), and is clearly the most effective GHG reduction step that fits that description. Yet it pretty much never gets mentioned by the enviros as part of their agenda. Perhaps this is because they do not want to be staring that choice in the face: There is something huge that any meat-eater can personally do tomorrow, just by deciding to do it. If they admit that, they have to admit that is true then they cannot keep pretending to themselves that they are willing to personally sacrifice for their cause.
Most notably, Mankiw did not mention what I am sure is his personal biggest contribution to GHG emissions, flying. How many miles do you have to fly in a year before the total contribution from that equals the sum of all your other consumption (not just driving and household utilities, but the energy impacts the material goods you consume too)? Don't quote me on this because I am working from memory, but I recall that it is in the order of 25,000. So for anyone who qualifies for even "silver" level frequent flyer status, that flying is more than half your GHG contribution for the year. I would be surprised if Mankiw flies less than double that.
Avoiding flying (or merely flying less), for the class of people who fly on airplanes, dwarfs anything else any of us can do to personally reduce emissions. This also means that a carbon emissions tax would fall most heavily on plane tickets, where it should. We could let this create the right financial incentive rather than relying on people who care about this issue to voluntarily avoid flying -- since observation suggests that they do not voluntarily avoid flying. For the class of people who do not hesitate to hop on a plane because they just want to be in another city for a couple of days, foregoing that option -- and thereby reducing their emissions more than everything else they can do, combined -- is a real sacrifice. So they decide it is better to just stick to buying those recycling bins, solar panels, and a cute cars (and put a wind turbine bumper sticker on them, of course). That way when someone drives by their 3500 square foot house while they are off visiting Paris, there will be no missing the message about just how wonderfully Green they are.