Recently, we reported on a study by researchers from the University of California Berkeley, which claimed that carbon credits generated from cookstoves largely overestimate the amount of CO2 emissions they avoid.
The claim is significant due to the vast share that cookstove carbon credits have in the global voluntary carbon market (VCM), which is roughly around 20%.
However, once the study was made public, a number of entities voiced their concerns with it, including Verra’s concerns with its fairness and Gold Standard’s comment on the lack of reflection of the VCM at large.
With the evident chasm between carbon credit opponents and proponents, we believed it best to also include the opinions of scientists, who believe cookstoves provide a number of benefits, including social, economic and environmental.
We interviewed Susanna Berkouwer, Assistant Professor of Business Economics & Public Policy at the Wharton School of the University of Pennsylvania, to learn what their cookstove research in Kenya has revealed.
Based on your research, what impact would you say the use of cookstoves has on climate?
We conducted a randomized controlled trial with 1,000 households in Nairobi to study the Jikokoa/ECOAchar cookstove (from manufacturer Burn). We collected five independent sources of data: Purple Air devices, charcoal ash weighing, high-frequency SMSes, in-person surveys, and phone surveys.
All confirm that buying a Jikokoa causes the buyer to use 40% less charcoal. Note that we are ambivalent about whether there is stacking: it is possible that some of the charcoal people purchase is used for their old stove. Any stacking would not affect our calculations in any way. What we care about is the total amount of charcoal used by a household, and that number goes down by 40%.
For the average user, a 40% reduction amounts to a reduction of 330 kg per year. Our calculations suggest that this causes a reduction of 3.5 tons of CO2 per year, in part because there has been significant deforestation in East Africa. If you want to be very conservative (optimistic) and assume that there is significant reforestation, then a more conservative calculation would suggest it causes a reduction of 1.75 tons of CO2 per year.
Because our study is a randomized controlled trial, we can calculate additionality very carefully. We know exactly how many people bought the stove without the subsidy (and therefore, among the people who did get a subsidy, how many people would have bought it anyway, even without a subsidy). We factor in these additionality rates when we do our calculations on the cost-effectiveness of cookstove subsidies.
In all, we find that subsidizing Burn’s charcoal cookstoves reduces emissions at a cost of between $4.90 – $9.80 (depending on the assumptions) per tCO2. This is *significantly* cheaper than almost any other technology available today (compare it with for example solar or EV subsidies, which are often hundreds of dollars or more).
Another way to put this is: for every $1 that the world spends reducing emissions, many more tons of CO2 will be reduced if we spend it on improved cookstoves than, say, on solar or EV subsidies.
What do you believe are the social and economic implications of cookstoves?
Charcoal is expensive. The 40% reduction in charcoal usage that we find in the randomized trial also allows people to save huge amounts of money that they normally spend buying charcoal. We find that the 40% reduction corresponds to on average $120 in fuel savings per year.
This is around one month of income for the average study participant. It’s truly a huge anti-poverty benefit. Most adopting households are very low-income families, who report that they use the additional cash savings for things like food, household products, or paying school fees.
Cookstoves already have a major share in the voluntary carbon market (VCM). Do you believe this space still has room to grow and why?
Yes. Billions of people across the world still use traditional cookstoves. I would look at the World Bank’s ‘The State of Access to Modern Energy Cooking Services’ report. As long as this continues to be the case, the scope for more people to adopt improved cookstoves will continue to be huge.
The recent University of California Berkeley study, which suggested cookstove carbon credits are largely flawed, caused a bit of a stir. Could you please comment on the findings of the study?
There are certainly many cookstoves that do not perform to the level that their carbon credits suggest. However, the UCB study omits several very rigorous academic studies, which indicate that there are stoves that do have major positive impacts, on par with the credits they receive.
Their article would have been much more accurate if they had said: “Many cookstoves are over-credited, but there are some that are high-quality and accurately credited. Conducting rigorous evaluations is important to help funnel funding towards the highest impact stoves.”
From your perspective, what can be done to improve MRVs for cookstove carbon credits?
Fund more rigorous independent evaluations! (Rather than relying on cookstove companies’ self-reported data).