UPDATED 03 July 2024


Gold Standard’s response to allegations of over-crediting in Clean Cooking methodologies


  • Gold Standard team,

On 23 January 2024 “Nature Sustainability” published a paper from the University of California, Berkley, titled “Pervasive over-crediting from cookstove offset methodologies”. This paper suggested that clean cooking credits are likely overestimated. This research is flawed and draws conclusions inconsistent with broader academic literature and expert views on clean cooking

Woman using an improved cookstove

Gold Standard values academic scrutiny and has provided feedback to the study’s authors over the past months. It is critical to note that the study did not find actual over-estimation. Further, its conclusions are not aligned with broader academic consensus, are not supported by the evidence provided, and are inconsistent with real data.

The paper compares carbon market data with research data, noting differences but overlooking the possibility of improved results in the carbon market due to factors like user training and stove maintenance incentivised by crediting mechanisms.

Gold Standard clean cooking solutions projects show CO2e average reductions of 2.4 to 3.2 tonnes per stove per year, in alignment with academic literature. We had already proactively updated our clean cooking methodologies in October 2021 to introduce more conservative default factors, improved monitoring requirements with safeguards and caps including maximum permissible levels for key inputs like baseline fuel and usage rate.

The pre-dominant source of overestimation according to the paper is associated with the fraction of non-renewable biomass factor (fNRB). This topic has not reached expert consensus, as evidenced by the continued discourse surrounding the recent publications by the UN’s Clean Development Mechanism (CDM). To understand more about clean cooking and fNRB, you can view our blog on the subject from November 2023.

About 2.3 billion people cook over open fires, impacting health and contributing about 2% of global climate emissions. Clean cooking projects are 'additional' because domestic cooking falls outside the productive economy, making it hard to subsidise or regulate. Clean cooking simply will not be rolled out at the speed and scale we need without carbon finance.

To play our role in catalysing finance to address this sustainable development injustice, we will continue to work with experts in the field of clean cooking such as the Clean Cooking Alliance to raise awareness of the issue among those who can invest in a clean cooking transition, optimise our processes and methodologies to ensure the best and most efficient impact measurement, and invest in capacity development to increase market access in frontline communities.

Research and expert views

Gold Standard cookstove projects typically achieve between 2.4 and 3.2 tonnes of CO2e reduction per stove per year, varying by region. Literature shows that a well performing cookstove project should achieve emission reductions aligned with this issuance. For example:

  • Berkouwer and Dean (2022) in their study "Credit, Attention, and Externalities in the Adoption of Energy Efficient Technologies by Low-Income Households" stated, “The reduction in charcoal consumption also reduces annual emissions by 3.5 tons of carbon dioxide equivalent (CO2e) per household.


  • D.L. Wilson, D.R. Talancon, R.L. Winslow, X. Linares, and A.J. Gadgil (2016) in "Avoided emissions of a fuel-efficient biomass cookstove dwarf embodied emissions" stated, “We estimate the embodied CO2-equivalent in the cookstove associated with materials, manufacturing, transportation, and end-of-life is 17 kg of CO2-equivalent. Assuming a mix of 55% non-renewable biomass and 45% renewable biomass, five years of service, and a conservative 35% reduction in fuel use relative to a three-stone fire, the cookstove will offset 7.5 tonnes of CO2-equivalent.


  • Carrie Lee, Chelsea Chandler, Michael Lazarus, Francis X. Johnson (2013) in “Assessing the Climate Impacts of Cookstove Projects: Issues in Emissions Accounting”, stated “The global technical potential for GHG emission reductions from improved cookstove projects has been estimated at 1 gigatonne of carbon dioxide (1 Gt CO2) per year, based on 1 to 3 tonnes of CO2e per stove.


  • Michael Johnson, Rufus Edwards, Adrián Ghilardi, Victor Berrueta, Dan Gillen, Claudio Alatorre Frenk, and Omar Masera (2009) in "Quantification of Carbon Savings from Improved Biomass Cookstove Projects", stated “Mean annual household CO2-e savings for CO2, CH4, CO, and nonmethane hydrocarbons were 3.9 tCO2-e home−1 yr−1 (95% CI ± 22%), and for Kyoto gases (CO2 and CH4) were 3.1 tCO2-e home−1 yr−1 (95% CI ± 26%), respectively, using a weighted mean fNRB harvesting of 39%.


  • The Environmental Protection Agency (EPA) estimates that “...each cookstove emits an estimated 2-6 tons of CO2 annually. Because improved stoves can reduce those emissions by 50-80%, many clean cookstove programs are eligible to receive carbon credits.


  • The World Bank, through its Rural Electrification and Renewable Energy Development II (RERED II) Project, supported the Bangladesh Improved Cookstove Program to disseminate 1 million improved cookstoves. This initiative was estimated to reduce emissions by 4.14 million tons per year, equating to approximately 4 tonnes per stove per year.

If the study was correct that projects are overissuing by 10x referred to in the study then, according to the studies above, we would be issuing up to 40 credits per stove per year, or alternatively that the correct amount to issue would be 0.1 to 0.4 - which is at odds with the broader evidence.

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