Updated: Biochar Ratings Framework

We have implemented targeted updates to our biochar assessment framework to strengthen scientific robustness, consistency, and transparency across projects.

Within the Carbon pillar, leakage assessment now evaluates both completeness of project-level analysis and inherent feedstock leakage risk. We introduced additional scrutiny on data quality through two new components: testing credibility and sampling rigour. Gross removal modelling has been updated to reflect a 200+ year timeframe, incorporating multiple recognised decay models and applying a range of plausible values for comparative assessment. Lifecycle boundaries are now cradle-to-grave, with continued focus on key emission drivers such as feedstock, energy, and infrastructure. Weighting between lifecycle emissions and gross removals has been refined, and carbon scores are now mapped to a transparent 1–10 scale.

For Additionality, greater emphasis is placed on financial transparency and carbon rights clarity. Financial analysis now carries more weight relative to grant assessment, and score caps prevent weak financial additionality from being offset by strong performance in other subtests. The overall scoring logic has been streamlined to better reflect true dependency on carbon revenue.

In Permanence, we enhanced geospatial risk assessment at the biochar application level, refined application method logic to distinguish best practice approaches such as deep soil incorporation, and updated soil classification using USDA texture mapping with adjusted weighting. Non-soil applications and general end-use monitoring are assessed with greater emphasis on MRV quality and traceability. Anthropogenic risk now appropriately constrains final permanence scores.

Under Safeguarding & Co-benefits, SDG evaluation has shifted to an activity-based, evidence-supported approach. Biodiversity and community impacts are assessed separately. Two new feedstock safeguards have been introduced: feedstock certification or proof of waste, and feedstock chain of custody. Contaminant and pollution prevention criteria have also been expanded.

Overall, these refinements were implemented to strengthen comparability, scientific robustness, and confidence in project ratings, while maintaining clarity and consistency for both developers and buyers.