Can you undo your emissions?

Many of us have some carbon-intensive element of our lifestyle that is structurally hard to change, or that we aren’t willing to give up. For me, one of those elements is flying. As I mentioned in my first post, nearly half of my carbon footprint comes from flying. Even if I only flew for trips I need to take for work and to visit my family twice a year, I would still be creating 5.4 tons of carbon emissions per year just from those flights. That’s between a third and an eighth of my total carbon footprint, generated in just a few hours per year. Add in any vacations at all, and the numbers get even worse. Are there any options for decreasing the environmental impact of these flights?

One option that is frequently discussed in this context is buying carbon offsets. The idea behind carbon offsets is simple: you figure out the carbon cost of a particular activity, like flying, then fund some kind of project that removes an equal amount of carbon dioxide from the atmosphere. While this is a simple concept, the reality of buying carbon offsets is quite complex, and controversial.

Buying carbon offsets has been compared by George Monbiot, a writer for the Guardian, to buying indulgences; that is, they are a way of clearing the conscience without actually demanding any action, allowing a continuation of our sinful, polluting ways. The counter-argument proposed by others like David Roberts is that the analogy to indulgences is broken. In the case of carbon dioxide emissions, we care that the total amount of CO2 stays fixed or, even better, goes down. This creates a concrete, quantitative way in which emissions and offsets relate to each other; if I emit 100 kilograms of carbon, and an offset project removes 80 kilograms, then the total amount of CO2 remaining in the atmosphere from these activities is 20 kilograms. Based on current available evidence, sin doesn’t work by the same mechanism: buying an indulgence for one bad deed doesn’t make that bad deed any less bad. However, reporters and scientists on both sides of the offsets issue generally agree that buying carbon offsets should be considered part of a holistic approach to reducing personal carbon emissions, rather than thought of as an excuse to indiscriminately emit CO2.

The most critical question for a consumer of carbon offsets, though, is ultimately whether they are effective or not in removing CO2 from the atmosphere. There are a set of international standards for assessing the effectiveness of carbon offsetting projects. These standards include additionality (would the project have happened anyway, even without offset funds?), permanence (how long will the carbon remain sequestered?), absence of leakage (are there unintentional effects outside of the boundaries of the project?), and verification (can a third party verify that the project being funded is operating as advertised?). Establishing additionality is both the most important factor in a carbon offset program, and the most difficult to verify. Duncan Clark, writing for The Guardian, highlights a hypothetical example in which an offsetting program distributes energy efficient light bulbs; however, if the local government would have started giving out the same  light bulbs to reduce pressures on the electricity grid, then this project would no longer be considered “additional.”

These kinds of issues recently led an EU commission to conclude that carbon offsets are not an effective means of mitigating CO2 emissions. The report suggests that over three quarters of the projects surveyed in the study do not meet the standard of being “additional” and less than 7% of the projects correctly estimated (and did not overestimate) their CO2 reductions.

Given all that, you’re much, much better off trying to reduce your consumption in the first place. But, since for most people it’s difficult or impossible to completely give up flying, driving or living in a house that uses power, buying carbon offsets for some set of your activities, in combination with efforts to reduce consumption, could help somewhat. There are several guides to the most effective kinds of carbon offsets; at a minimum, even if these projects aren’t really “offsetting” carbon emissions per se, the work they are doing is heading in the right direction. The Gold Standard is generally considered the highest standard for carbon offsetting projects; you can support their projects here.

As someone who occasionally travels for work in addition to other trips, I was also interested in work done by the organizers of a conference on programming languages, who have done a very detailed and interesting assessment of the climate impact of organizing and holding their conference. They cite research from Stockholm Environmental Institute that suggests that methane capture and landfill gas capture projects will be the most effective and non-harmful methods of offsetting carbon. They conclude that in the short term, in the absence of all the other climate preserving activities that should be pursued by governments, etc., that purchasing carbon offsets for their conference-related activities could help minimize the environmental impact of hosting the meeting.

For me, given all of this information, I plan to purchase carbon offsets for the flights I will take this year. I’ll keep you up to date on what choices I’ve decided to make and how much they ended up costing. Even though they’re not even close to a perfect solution, I think it’s better than doing nothing, and are a concrete way to support the work many of these carbon offsetting projects are undertaking. I also plan to try to fly less in general this year by combining work and personal trips whenever possible, and keeping my vacations more local this year. For example, I’ll be taking a work trip later this year to the east coast, and will extend that trip to see friends, to save making a separate trip later in the year.

What do you think about carbon offsets? Would you buy offsets for your flights, or the energy used by your home?