Transparency, robustness, and consistency in aboveground forest carbon quantification methodologies used for tropical forest carbon projects: a review in Southeast Asia

Forest carbon projects hold significant potential for mitigating greenhouse gas emissions. However, growing scrutiny has raised concerns about their climate integrity, particularly the gap between scientific knowledge and the practical implementation of carbon quantification methodologies. Southeast Asia, a rainforested tropical region, is a key focus for the development of forest carbon projects. This study critically reviewed the quantification methods and associated reporting of 69 forest carbon projects across Southeast Asia, guided by three essential and interrelated criteria: transparency, robustness, and consistency. The findings reveal limited disclosure in methodological reporting, the adoption of potentially unreliable quantification practices, and substantial variability due to the differing standards adopted by projects. These issues risk undermining the credibility of carbon credits and may hinder their alignment with national and international climate goals. By identifying key methodological gaps and proposing clear evaluation criteria, this study contributes to ongoing debates around forest carbon credit integrity and underscores the urgent need for more transparent, rigorous, and standardised carbon accounting practices within the sector.