Counting Calories and Counting Carbon: The Role of Offsets in our Climate Diet
Posted Mar 18 2009 3:19pm
“To illustrate the difference [between carbon offsets and allowances], consider two people trying to lose weight. One person decides to meticulously count the calories of the foods he eats, with the goal of reducing his intake each day. The second person, however, counts the calories of the foods he thinks he would have eaten that day but did not because he was on a diet. You can imagine which of the two will be more likely to actually shed a few pounds.”
Emily Figdor Global Warming Program Director of Environment America
By Aimee Barnes and Marc Stuart
The quotation above was spoken during the U.S. Congressional hearing on the “potential role of offsets as a cost-containment mechanism in a U.S. cap-and-trade program.” two weeks ago. Host to this meeting was the House Subcommittee on Energy and Environment, chaired by Rep. Ed Markey, and widely anticipated as playing a vital role in the future shaping of U.S. climate legislation. Like most good analogies, it’s catchy, is framed within an everyday issue that most people understand and seems easy to comprehend. Unlike most good analogies, it’s also dead wrong.
In the analogy quoted above, the first person described who attempts to lose weight by counting calories is parallel to a regulated source, where in theory it should be easy to take stock of the total emissions and simply reduce what is necessary to reach target levels. The second person described, who attempts to lose weight by establishing a counterfactual of what he would have eaten but did not because he was on a diet, is at least in theory, parallel to a carbon offset project. Obviously the ridiculousness of the setup is intended to persuade the listener that offsets are equally ridiculous and should be rejected from any cap-and-trade program. After all, they are based on a scenario that never actually happens! (The irony that climate change itself is a counterfactual is not lost on us... but that’s for another blog.)
Let’s take the analogy and rework it a bit. Consider two people trying to lose weight. Both weigh 150 pounds and each wants to weigh 140. The first decides to meticulously count the calories he eats. But how can we be sure this person knows exactly how many calories they must eat to reach their goal weight? Likewise, many emitters may not have as precise an understanding of how to achieve greenhouse gas reductions as we would like to think. Setting this uncertainty aside, let’s assume the person knows how many calories to eat to reach his goal weight. Aided by precision, this first person will lose exactly 10 pounds to reach their goal weight of 140. In a precise world, emitters could do the same to achieve exact reductions to meet their goals.
Now let’s look at the second person. Applying the metaphor of the offset project, when this second person establishes her counterfactual of how many calories she would have eaten in the absence of the diet, the real parallel here is the “baseline” of the offset project—in other words, what would have happened without the project (or the diet). In the weight loss scenario, the second person reasons how best to lose 10 pounds taking into account their calorie “baseline” and the absence of true precision. So the second person might say to herself:
“If I did not go on a diet, I would usually eat around 2,000 calories. However, since some days I am busy and only eat around 1,700 calories, I will use that conservative estimate as my “business-as-usual” scenario. I know I should eat around 1,500 calories daily to lose 10 pounds, but I can’t always measure the precise caloric value of the foods I eat. To be safe, I’ll aim to consume 1,400 calories a day and use conservative estimates for the caloric values of the foods I do eat. That way I can avoid overshooting my limit and be sure to meet my goal.”
Giving equal consideration to both approaches, the weight loss winner is not as clear as the original metaphor suggests. The first person may be more precise in their weight loss, while the second person may be more conservative to compensate for a lack of precision and thereby potentially lose even more than the first person. If all we focus on is the target of 140 pounds, then that second person might even not receive “credit” for losing additional pounds and surpassing the goal. True, the second approach is less precise, but conservativeness proves an equally effective strategy to reach the same goal. Contrary to what the original quotation implies, one cannot go around claiming that one’s forthcoming diet will consist solely of whipped cream pies. Similarly, great efforts are made to ensure that the baseline of future emissions behavior is appropriate and realistic to the situation for offsets projects.
Now let’s take the metaphor a step further. Assume that the two people are trying to lose weight because they must get into an elevator that can only hold 280 pounds. The weight limit in the elevator is similar to our planet’s capacity for safely absorbing greenhouse gas emissions. Assume one person weighs 150 pounds and cannot lose any weight. The only way she could do so is by cutting off her arm, which weighs 10 pounds. For obvious reasons, this would be very inconvenient and messy. The second person weighs 140 pounds, and could easily lose 10. This person is also holding a 10 pound briefcase, so effectively weighs 160 pounds total. The easiest solution would be for this person to lose 10 pounds and then simply toss the briefcase out of the elevator to reach the weight limit. However, by suggesting that offsets be excluded from a cap-and-trade program we are essentially asking the first person to cut off their arm rather than simply asking the second person to get rid of their briefcase.
Figdor’s diet metaphor isn’t entirely flawed though: counting calories and counting carbon are in some ways surprisingly similar. For example, we might assume that a 100 calorie Snack Pack contains 100 calories exactly. In reality, however, food science is not that precise. Acknowledging this, the FDA requires food companies to regularly test their product to make sure the calorie content is within an acceptable margin of error of what is claimed on the label. So while on average, Snack Packs have 100 calories, your particular Snack Pack could have 95 calories, but it might also be packing 110! Since we don’t quite know in each individual case, the basic scientific concept of conservativeness is applied, and Kraft errs on the side of more snack packs having 95 calories so those on a diet don’t go over their limit. FDA oversight exists to prevent producers from cutting corners and make sure that the calories in the packs are what the company says they are.
The same theory applies to calculating how many credits an offset project should receive. In most cases we have advanced technologies such as continuous flow meters on site - the calibration certifications alone for meter efficacy in our projects have driven some of our team to drink!! - that must be installed at a project to monitor and record the key data points that create emission reductions. In many cases, emission reductions at a project site are probably recorded with more rigor than the calories in your snack pack, and in cases where there is some uncertainty, project developers are generally required to pick the most conservative number, to which a haircut is then applied. To make sure that corners aren’t being cut, third party verifiers (essentially like tax auditors) review all the details of the project to make sure no one is bluffing. Moral of the story? If your 100 calorie Snack Packs were monitored as strictly as your offsets, you might shed a few pounds and reduce your carbon footprint.
Aimee Barnes is senior manager of U.S. regulatory affairs at EcoSecurities, a company working to mitigate climate change through projects that reduce greenhouse gas emissions globally. Marc Stuart is the Co-Founder and Director of New Business Development for EcoSecurities. The views expressed are their own and do not necessarily represent the view of EcoSecurities.
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