Verra, a leading organization in voluntary carbon markets, developed the Verified Carbon Standard (VCS) Program to ensure the credibility of GHG emission reductions. The verification and measurement methodology VM0042 is designed to estimate and verify GHG reductions and removals in agricultural settings, particularly through regenerative practices that increase SOC storage, such as, but not limited to, reduced tillage and improvements in fertilizer application, biomass residue and water management, cash and cover crop planting and harvesting practices, and grazing practices. The Metholodgy was first introduced in the 2020 (v1.0), and was updated in May 2023 (v2.0). As of August 2024, VERRA has again proposed several revisions and hosted public consultation webinars to solict feedback.
Methodology Overview: The methodology determines additionality and crediting baselines using a project-based approach. The baseline scenario assumes the continuation of existing ALM practices, with a historical look-back period of at least three years to establish pre-project activities. SOC stock changes and GHG emissions are modeled or directly measured against this baseline. Additionality is demonstrated by showing that the adopted ALM practices are not common and face barriers to implementation.
Quantification Approaches
- Measure and Model: Uses biogeochemical models to estimate GHG fluxes related to SOC changes, soil methanogenesis, and nitrogen fertilizer use. Periodic SOC stock measurements are required.
- Measure and Re-Measure: Directly measures SOC stock changes in cases where models are unavailable or unvalidated.
- Default Factors: Applies default emission factors for CO2, CH4, and N2O emissions from sources like fossil fuel combustion.
Conclusion: This methodology supports GHG mitigation in agriculture by promoting practices that enhance SOC storage and reduce emissions. It offers flexible quantification approaches, accommodating diverse agricultural systems and practices. Regular reassessment ensures alignment with current agricultural practices and environmental conditions.