A transit blog gone off the rails

A digression/humblebrag/mea cupla on carbon offsets for air travel

This post is intended as an addendum to this one. If you got here from somewhere else, well, spooky.

While aviation only accounts for about 2% of global emissions, it’s a heavy hitter in many Americans’ carbon footprints – mine included. A certain amount of my self-identity is built around being a big trains guy and not eating meat, I’m fully aware that due to the amount of flights I take, my carbon footprint is probably larger than a lot of Americans who drive everywhere but have the decency of mostly staying put on a continental scale.

Recently I’ve made a foray into trying to change that by buying carbon offsets based on the number of miles I fly. A round-trip SF to NY flight puts about two tons of CO2 into the atmosphere for each economy-class seat, and there are a menagerie of businesses and nonprofits happy to take your cash (at about $10-20/ton CO2) and put it towards projects that are carbon-negative, essentially cleaning up your carbon mess behind you. The idea is sound, but using this technique to balance the books on your personal carbon output is a messy business.

The sources and quality of carbon offsets vary greatly, but the key feature of effective ones is additionality – it should be readily apparent how your contribution pays for an additional, incremental reduction in emissions. So paying a farmer to divert their methane emissions at a certain cost per pound has a stronger sense of additionality than, say, throwing money towards a wind farm project that would have been funded by government subsidy anyway. Ideally the offset should happen during an identifiable and short window of time, which makes planting trees a particularly risky choice; they can die, burn down, or get outbid on by loggers well before they capture a lifetime’s worth of CO2. At any rate, in the absence of any government-enforced certification for offsets, you can really only take the provider at their word.

The other problem is that while offsets seem surprisingly affordable, at least to the jet set, this is largely so because the projects doing the offsetting represent extremely low-hanging fruit in the carbon capture space; if everyone in the US decided that they wanted their air travel to be carbon-neutral tomorrow, there wouldn’t be enough emissions-capturing infrastructure to go around, and the price would rocket upwards. In this sense, it’s little more than a mechanism for the wealthy to pay the less affluent to burn less carbon so they don’t have to.

So it’s safe to say that carbon offsets aren’t going to save the world, but they’re not doing nothing, either, so in the end I double-offset my flights for this year at a total cost of about $50/month, hedging my bets with both Native Energy and Terrapass. Obviously not everyone can afford this, but most people who fly frequently can, and since my employer is going to pay for the bulk of my air travel this year, I figure it’s the least I can do. Is it effective? Maybe. Do I feel less guilty? Eh, kinda. The chain of cause and effect between me tossing some money into a Stripe form and the world becoming somehow less bad is too abstract for me to really wrap my head around. In the end, reducing aviation emissions is going to take a combination of new technologies, personal sacrifice, and – one would hope – the return of the mighty zeppelin as our primary mode of air travel.