I’ve never understood opposition to carbon offsets on moral grounds — that “being green” is virtue that has to be earned and can’t be bought. The usual comparison is to papal indulgences, the practice of buying forgiveness for your sins whose rampant abuse in the Roman Catholic Church partly caused Martin Luther to leave it.
The difference is that God’s forgiveness wasn’t the Church’s to sell. If you can actually pay for a project that actually does remove carbon from the atmosphere, a carbon offset isn’t cheating. It might not be morally satisfying, in that it’s an option available to the rich that isn’t available to the poor, but, well, lots of things are available to the rich that aren’t available to the poor and we don’t as a rule say the rich can’t have them.
The point isn’t that being green is virtuous in itself, but that being grey-brown is harmful — and if you can structure your affairs so as to be carbon-neutral or carbon-negative, as far as I’m concerned you go right on ahead.
The trick, however, is that the people selling you your offsets have to have genuine offsets to sell. I’ve written here about a couple of schemes that strike me as unusually sketchy, but doubtless there are dozens or hundreds more. There’s no international verification standard, and usually a retail-level trafficker in offsets is promising to do something in a far-off land that you can’t go see yourself. Typically, he or she is promising to plant trees, on the theory that as they grow, they’ll “fix” carbon from the air in their physical structures.
This is fine as far as it goes, but Grist Mill has been doing some serious practicality checks on the subject and finds the actual practice of tree-planting to create carbon offsets seriously wanting:
The biggest one is timing. A carbon offset represents not just a specific amount of greenhouse gas reduction, but also a specific period in which the reduction takes place. One of the most basic principles of offset quality is that, other things being equal, you want to sponsor reductions that are taking place now, not at some far-off point in the future.
Unfortunately, trees grow rather slowly. And particularly when they’re small, they don’t sequester much carbon. The small print on tree-planting offsets typically indicate a 40-year maturity. If you buy a tree-based offset today, you’re sponsoring a reduction that won’t be complete until 2047, by which time we’ll either be living in hurricane-proof seaside bunkers in the Rockies or flying around in hydrogen-fueled jet cars.
Plus trees have a way of dying on you, of collapsing and rotting out or of burning, either of which puts that carbon right back in the atmosphere with the stuff you put out and were trying to offset.
We desperately need some standards for measuring and monitoring tree-based offsetting projects, and I wouldn’t take seriously anyone’s claim to have offset his or her own carbon emissions using such projects until we’ve got a licensing regime in place.