There has been a spate of questions on the Green School listserv (GRNSCH-L@listserv.brown.edu) about offsetting greenhouse gas emissions locally and actively, as opposed to remotely by writing a check. The nutshell conclusion is that local action is always the best ("Think globally, ..."), and offsetting GHG emissions presents a clear case why.

To put things into context, remember that any offset is the least preferred option when it comes to ecological sustainability. Reducing your environmental impact by decreasing energy (or materials) use is generally the simplest, most direct (hence, most efficient) way to go. Substituting renewable resources (including energy) for what you can’t eliminate through reduction is a good second step. But what if you absolutely need to consume resources (like electricity or gasoline or paper), and you just can’t find a renewable (clean) substitute? That’s when offsets come into play.

If you offset your greenhouse gas emissions, for example, you continue to emit. But you try to make up for your sins by paying someone else to (or make it possible for them to) reduce their emissions. Net/net, worldwide emissions go down and you caused it to happen. What’s not to like?

Well, for starts, what’s not to like is that you’re still emitting. You’re still sinning. A couple of jokers (as I recall, it was in the UK — anybody remember the specifics?) established a system of marital fidelity offsets to spoof the logic of offsetting GHG emissions. As the name implies, under their system a spouse could commit infidelity, but make it all OK by paying someone else to be true to their wife or husband, so that the total level of infidelity in the world wouldn’t be affected! It was all in fun (I hope!), but there’s an element of truth to the punch line.

Two things make real-world emissions offsetting more than a bad joke, though. Most obviously, there’s no individual, enraged spouse in the picture, so you’re less likely to start finding antifreeze in your lemonade. And, on the flip side, global CO2 levels are, of course, a global problem. If there’s a way to achieve a true net global reduction, it really doesn’t matter to the climate just who’s putting out the remaining greenhouse gases.

The fly in the offsetting ointment is that bit about achieving a true net global reduction in emissions. Most offsets are purchased in arms-length transactions, so the purchaser really has no control over whether someone else’s emissions actually go down (or, equivalently, avoid going up). For offsets to be valid, the minimum conditions include:

1. They have to be real. The activity generating the offset has to be in the form of a physical, tangible project with a demonstrable outcome. The infrastructure involved can be already in place or imminent, but it has to exist.
2. They have to be measurable. Anybody can estimate anything, but not all estimates are equally meaningful. When an activity reduces (or avoids) greenhouse gas emissions, you can’t directly measure the CO2-equivalent that wasn’t generated — you have to estimate (calculate) it. To be taken seriously, the estimating algorithm has to be robust, transparent and readily explicable. In the best case, the algorithm will be reviewed and approved by a credible third party (think accrediting agency).
3. They have to be permanent. It doesn’t count if someone defers emissions which would normally occur this year, if they simply pop out in some future timeframe.
4. They have to be additional. Here’s the rub. If you want to expiate your sins by paying someone else to be virtuous, the person you pay can’t already be a living saint. In this case, you can’t offset your emissions by paying to avoid emissions which really weren’t going to happen anyway, or to implement emission reduction projects which were.

If you buy your GHG offsets in arms-length transactions, the first three points are hard enough to achieve. The fourth one is almost impossible, without help. Help is available. A recently updated report from Business for Social Responsibility lists currently available standards for GHG offsets, and organizations which are set up to enforce them. It’s well worth a read.

For colleges and universities, however, there’s no place like home to do your offsetting. Don’t make your offsets at arm’s length, clutch them to your bosom. Implement efforts to reduce off-campus emissions as co-curricular activities. The University of Colorado recently switched all its offset purchases to the Colorado Carbon Fund, which will invest in local projects to reduce energy utilization by Colorado households. Oberlin College is making plans for a major CFL exchange program. Brown will make grants to student organizations to curtail carbon use in the local community. I’m sure the list goes on.

The advantages of local offsets are clear. It’s easy to see that the reduction is real and permanent, if you help make that reduction yourself. You get to do the reduction estimation, and you can make the algorithm as rigorous as you please. And you can know it’s additional reduction, especially if you target your efforts to communities which — often for financial reasons — wouldn’t be able to make reductions on their own. As gravy, a local offset program can improve town/gown relations.

GHG offsets can never be the whole solution. All of us are going to have to both reduce and substitute, or global warming will be, at most, only slowed. So the approach of the College of the Atlantic, which declared climate neutrality after offsetting 100% of its emissions, can only work in the short term. But, in the short term, offsets should be a part of every institution’s climate strategy. And, if we achieve them locally, as a part of the co-curriculum or however we think best, they can make sustainability awareness and climate action a palpable part of each student’s educational experience.