With an estimated 2.6 billion people relying on traditional biomass for cooking and heating, improved efficiency of cookstoves could provide greenhouse gas emission reductions in excess of one billion tons of carbon dioxide equivalent per year. One policy mechanism for realising and monitoring this potential is carbon finance, though estimating emission reductions of cookstoves projects is a challenging task. This paper evaluates the quantification approaches aimed at overcoming these challenges, drawing on a literature review and interviews with technical experts and market actors to identify lessons learned and knowledge gaps. It begins with a review of the current carbon market activity with regard to cookstove projects, with several having attracted carbon finance through the Clean Development Mechanism (CDM). Additionally, voluntary market offset programmes such as the Gold Standard, the American Carbon Registry and the Verified Carbon Standard are also highlighted in a comparative study of their characteristics. The following three key parameters required to calculate emission reductions under present frameworks are identified.

Estimating biomass fuel savings: the Water Boiling Test is simple and replicable in the laboratory but unrepresentative of field conditions, whereas the Kitchen Performance Test has difficulties controlling sources of error. The Controlled Cooking Test is a compromise, using local cooks, on location in test kitchens. All three require improvements, such as the incorporation of uncertainties.
Assessing the impact of biomass consumption on carbon stocks: calculating the amount of non-renewable biomass saved through increased efficiencies is difficult. The CDM has identified indicators as evidence of non-renewable carbon stocks, but inconsistencies in accounting methods, as well as the inappropriate use of national-scale data (which can hide local sustainability problems), add considerably to a sense of uncertainty. Efforts to standardise primary local data should continue.
Estimating carbon dioxide emissions from cookstoves: a significant issue is that fossil fuel factors are used to calculate baseline fuels (due to restrictions on CDM covering avoided deforestation), despite wood fuel emitting roughly double the carbon dioxide per unit fuel energy compared to LPG or kerosene. Revisiting this issue will require a lengthy review period with uncertain outcomes.