Carlos F. Gould 

Carbon markets are thought to be central to global climate strategies,1 but their scalability depends on the credibility of emissions reduction claims,2 a point that has recently faced scientific and public doubt.3,4 Carbon projects typically generate their own estimates of averted emissions to produce credits, a practice that introduces potential conflicts of interest and underscores the need for rigorous oversight. Focusing on cleaner cookstoves, we explore the difficulties in using academic studies as benchmarks for evaluations of carbon projects and highlight how methodological choices shape both evaluations and conclusions. Reexamining one influential study on cookstove carbon project overcrediting5, we show that under alternative assumptions consistent with the state of the science estimated overcrediting falls by half. While the overall sector still exhibits worrisome overcrediting, one-fifth of projects analyzed show no clear evidence of it. Enhanced collaboration between researchers and project developers, we argue, is essential for improving the accuracy of carbon market assessments and ensuring that these initiatives deliver genuine social and environmental benefits.