In late medieval times, the Catholic church raised money by selling indulgences, certificates that offered believers absolution for their sins. Not a bad deal, when you think about it. Good works take time and effort. Giving alms is so much easier.
Many folks are convinced a similar scam is going on today. If emitting greenhouse gases is the new sin--and so it would seem, given the moralism that surrounds climate change--then carbon offsets are the new indulgences, the way to absolve sin without sacrifice. This analogy has occurred to several commentators independently, from right-wing loudmouth Rush Limbaugh to dark-green climate crusader George Monbiot. There must be something to it, right?
Perhaps. But not much. Offsets and indulgences differ in important respects. The tendency to conflate them reflects our peculiar thinking about the fight against global warming.
Voluntary carbon offsets (not to be confused with government-run carbon-trading markets) went from obscurity to ubiquity almost overnight. According to a recent report, the market grew by 200% between 2005 and 2006, to more than $90 million. The backlash arrived just as quickly, driven in part by legitimate technical questions, but primarily by a gut reaction: that paying other people to reduce their emissions rather than reducing your own is a cop-out.
But think for a moment about the signal characteristic of sin: It is personal. Your sins are uniquely yours to answer for; it's your eternal soul in the balance. Your greenhouse-gas emissions aren't like that at all. The amount of emissions for which you are personally responsible is irrelevant--we're all in this together. What matters is the aggregate amount of emissions. The atmosphere doesn't give a fig where a molecule of carbon dioxide originated, nor does it care where a molecule of CO2 emission is prevented. If it's quicker, easier, and cheaper to prevent a ton of emissions by purchasing an offset than by altering your lifestyle, why not buy the offset?
This incentive--to do what's quickest and easiest first--is not a bug, but a feature of virtually all policies intended to mitigate climate change. Carbon taxes, government-mandated carbon-trading markets (such as the EU market, or the regional initiative in the northeast United States), and voluntary offsets are designed to channel money toward the low-hanging fruit. As the cheap reductions are achieved, the price of carbon, and carbon offsets, will go up. That's the point of a market-based system.
There are, of course, legitimate questions about whether specific offsets do what providers claim: reduce a precise amount of emissions. The market is not governed by federal regulations, although prominent members of Congress have requested that the EPA begin developing standards. The widely respected Center for Resource Solutions is developing a certification program for offset providers, but none are currently certified. (CRS does verify footprint balancer TerraPass under a separate program.) Many top-tier providers use other kinds of third-party certification.
For now, you should pick a provider with care and pay close attention to where it puts your money. Avoid projects in which the promise of reduction is in the distant future. The most popular offset is also the most suspect: tree planting. The reliable reductions come from renewable energy, methane capture at landfills and sewage treatment plants, and cogeneration (recycling waste heat from power plants and factories).
Ditch the guilt. You aren't a sinner for buying offsets, regardless of what you do about your own emissions. CO2 is fungible, like money, not personal, like sin.