Estimated Carbon
Effectiveness Of Carbon Offsetting Projects
How Do Carbon Estimates Perform In The Real-World?
The early data isn't reassuring. As reported by S&P Global: "Only about 3% of offsets today represent actual removals of emissions from the atmosphere, according to Carbon Direct".
This research showed that "at least 52%" of carbon offsets in India (specifically wind turbines) were bogus. Usually, it because these projects would have been built anyway, regardless of offsets being sold1. In fact, the study even claimed that these types of carbon offsets actually raise the carbon dioxide levels.
This unpopular fact was quoted by John Oliver in his segment on greenhouse gases: "study after study has indicated that most offsets available on the market don't reliably reduce emission"1.
Why Forest Management Makes No Sense
Most credits sold are forest credits (at least in California, the largest cap and trade jurisdiction in the world today)2. And most of those forest credits are Improved Forest Management (IFM) credits, though they should be called 'wishful thinking' credits. IFM sellers often make dubious claims about the accuracy of their carbon estimates.
In projecting the future (or alternate scenarios), some natural error is to be expected. But it may not surprise you to know that carbon estimates seem to be biased in one direction: towards being overly optimistic (i.e. counting more credits than they are eventually realized in actuality)2. In this case, the lot-specific assumptions in California may inflate credits by up to 30%).
Sometimes for instance, naturally occurring forest fires can disrupt forest "conservation", even though their frequent occurrence should be easy to build into a model (insurance companies write policies that cover forest fires, so it must be possible to reliably derive their likelihood for a given area). Omitting such known variables in calculating carbon offsets seems like a deliberate choice, one to avoid diluting their project's perceived benefits.
In All Fairness, Not All Projects Are Forest Management Schemes
Beyond forest management credits, there are some projects that have testable effects on the environment. Cooking stoves are a good example (as Wendover Productions explained). Consider that many parts of the world still rely on a wood-burning fire to cook meals (areas encompassing about 3 billion people). The rudimentary setup usually involves an inexpensive pot balanced over a three rock fire. The system is popular in areas where electricity isn't available (or reliable). Unfortunately, that ancient method of cooking is grossly inefficient. A majority of the heat created is carried into the air rather than transferred to the pot. Compare its 10% efficiency to a standard electricity stove operating at 70% or 80% efficiency.
Fortunately, there is a easy solution: replacing these old setups with a new cooking stove that sports an improved design, which better preserves the heat generated by the burning of biofuels. These cookstoves can be made for about $20 and in theory should reduce carbon emissions by about two thirds (based on their efficiency rating of over 20%). Selling credits today allows NGOs to give out the new cookstoves wherever they are needed. All that needs to happen, again in theory, is for the new kitchen accessories to be used as directed over their predicted lifespan, say 20 or 30 years. Easy peasy right?
Well no! Turns out that the initial carbon estimates have been proven to be way off. In a real world experiment, families with the new cookstove barely reduced their carbon emissions (less than 15%). While the stoves themselves did allow less heat to escape as designed, families started using them more often than their old-fashioned 3-stone stoves. Precisely because they consumed less wood (or less coal), it was possible for their owners to increase their usage substantially. The well-intentioned modelers had not forecast the unmet demand from villagers to cook a greater share of their food. In fact, it led to situations of "oven stacking", where families either kept their old stove or acquired new ones, in the goal of having several pots all going at once. In other words, the technological improvement had spurred suppressed demand amongst the locals, an unintended consequence. Leakage had entered the system!
As a result, wood consumption from this cookstove replacement replacement program went from 9.3 lbs to only 7.9 lbs a day on average, a barely statistical significant decrease. But by then it was too late, the credits for a two thirds reduction had already been "baked in" (no pun intended) into the carbon estimates2.
