Cookstoves

A comprehensive quality assessment of cookstoves carbon credits

Roughly 2.4 billion people cook with smoky biomass or kerosene, contributing to 2-3 million premature deaths annually and roughly 2% of global greenhouse gas (GHG) emissions. Efficient stoves can reduce emissions by using less fuel or switching to a less GHG-intensive fuel and achieving more complete combustion which emits less methane and other pollutants. They can also reduce time spent collecting fuelwood, which can be hours a day, or the cost of procuring fuel, which can be a substantial portion of household income. Unfortunately, only a small share of stoves—liquified petroleum gas (LPG), electric, ethanol, natural gas/biogas/compressed natural gas, and the Mimi Moto and SupaMoto biomass pellet gassifiers—reduce smoke enough to substantially avoid negative health impacts.

Cookstoves are the fastest-growing project type on the voluntary carbon market and many distributors of efficient stoves rely on offsets to subsidize the cost of their stoves. Accurately and conservatively quantifying the climate benefits of efficient cookstoves matters tremendously. These carbon credits are being used by companies to meet emissions reduction targets and sell carbon-neutral products. If the credits do not represent real emissions reductions they can take the place of true emissions reductions and justify ongoing emissions. They also can undermine trust in the market, and its ability to support these projects going forward.

In our journal article, Pervasive over-crediting from cookstove offset methodologies, published in Nature Sustainability, we comprehensively, quantitatively, and systematically assess how well the five cookstove offset methodologies that have generated almost all cookstoves offset credits to date quantify the climate benefits of improved cookstove projects.

This website translates our study into clear, accessible explanations of how the methodologies work, summary of our findings on credit quality, and guidance on how credit buyers and project developers can trade in quality credits from stoves that substantially improve user health. We also provide clear recommendations for how cookstoves offset methodologies can be revised so their credits can be trusted, and methods for performing quality assessments of any offset methodology.

Poor credit quality on today's market

Our sample of projects, which had generated 40% of credits from the cookstove methodologies we studied, generated 9.2 times more credits than our estimates of their true emissions benefits. Extrapolating to the whole market, we found that the pool of credits generated by these methodologies are over-crediting by over 10 times. This over-crediting is mostly from exaggerated estimates of stove adoption and use, underestimates of the continued use of the original stove, and high estimates of the impact of fuel collection on forest biomass.

⇒ How the Methodologies Work for background
⇒ Results & Quality Factors for more detail on our analysis and results
⇒ Guidance for Developers for a summary of our recommendations on how to estimate emissions reductions and amend the methodologies to accurate estimate project benefits

A small portion of stoves substantially improve health

Breathing in fine particulate matter increases the risk of a range of health impacts to the lungs and cardiovascular system, including chronic respiratory disease, pneumonia, lung cancer, stroke, and cardiovascular disease. While any stove that reduces the use of fuelwood can improve people's lives and well-being by reducing the time and money spent collecting or purchasing fuel, only some stoves reduce indoor air pollution enough to meaningfully improve health. This is because health impacts and exposure are not linearly related. Stoves must be very clean to have health benefits; and stoves that are have striking health benefits.

Gill-Wiehl & Kammen propose a “pro-health” fuels and stoves agenda based on the World Health Organization (WHO) standards, stating that, “energy, social, and ecological justice demand that we prioritize the health needs of those cooking daily over an open fire, rather than those wanting to buy cheap carbon credits to justify continued GHG emissions.”

Today, the stoves that meet WHO health standards use liquified petrolium gas (LPG), ethanol, bio-ethanol, natural gas, electric, and two biomass pelet gassification (Mimi Moto and the SupaMoto).

⇒ More on Health Benefits

Guidance for credit buyers and project developers

We offer clear guidance for credit buyers to help credit buyers identify quality credits on today's market, and guidance for project developers to help cookstoves project developers choose stoves that meet WHO health standards and generate quality credits.

In short, we recommend projects that distribute stoves that meet WHO health standards and use Gold Standard’s Metered and Measured methodology. This methodology, which directly monitors fuel use, are most aligned with our estimates (1.5 times over-credited). It is also best suited for fuel switching projects, which provide both the most abatement potential and also the most health benefit.

As a rule of thumb, buyers and developers can use this "matrix of quality" to identify quality cookstove offset projects.

⇒ Guidance for Credit Buyers
⇒ Guidance for Project Developers

Methods for assessing offset quality

The high levels of over-crediting we found are not unique to cookstove projects, but an example of a much bigger crisis of quality in the offset market. Other studies have found similarly high levels of over-crediting by the UN’s Clean Development Mechanism (e.g., Cames et al., 2016; Haya et al., 2010), improved forest management methodologies, and reduced emissions from deforestation and forest degradation (REDD+) offset methodologies, among others (see our Repository of Article on Offset Quality).

Our journal article developed and demonstrated how an over/under crediting analysis can be used to systematically assess offset quality under different methodologies across all estimation factors for any project type.

⇒ our journal article Pervasive over-crediting from cookstove offset methodologies
⇒ guidance on how to perform a comprehensive over/under crediting analysis of offset projects

We release these guidances to show how cookstoves can be a rare quality offset project type that credit buyers can trust.

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