WBA responds to ISCC PLUS GHG Add–on Consultation
World Biogas Association (WBA) on 20 April 2026 submitted its response to the International Sustainability and Carbon Certification (ISCC) PLUS GHG Add-on Document Consultation.
ISCC PLUS is a voluntary certification scheme designed to validate the sustainability characteristics of alternative feedstocks for plastics and chemicals, food and feed markets, and biofuels outside the regulated European Union and the UK markets (global). It plays a key role in cross-border biomethane trading.
The purpose of the “ISCC PLUS GHG Add-on Document” is to explain the use of the voluntary GHG add-on under ISCC PLUS for stating greenhouse gas (GHG) emissions values along the supply chain and to provide the methodology, rules and guidelines for calculating and verifying GHG emissions and emissions reduction.
WBA identified a number of gaps, ambiguities, and omissions that, if left unaddressed, would materially undermine the document’s utility to the biogas and biomethane industry.
Application of the GHG Add-on under the Free Attribution Approach
As currently drafted, the GHG Add-on is effectively prohibited under the Free Attribution Approach whenever “compensation of input characteristics” has been applied at any point in the supply chain. WBA urged ISCC to revise this provision to explicitly accommodate the mass-balance registry model used for gaseous fuels, including a dedicated biomethane grid pathway under the Free Attribution Approach.
Consistency over project-specific emissions values, compression DDV and document terminology
WBA recommended consistency, the establishment of clear and harmonised definitions throughout the document and the inclusion of examples and images to enhance clarity.
Recognition of Methane Mitigation from Manure Management as a Distinct Bonus Category
WBA proposed that ISCC consider treating manure management as a separate category or sub-bonus distinct from other activities, such as soil carbon practices, given that methane avoidance from manure management is an immediate, measurable, and permanent climate benefit, whereas soil carbon accumulation is a slow, diffuse, and difficult-to-verify process.
Clarification on the eligibility of non-traditional land restoration pathways under theeb bonus
It is not clear from the proposed document whether non-traditional land restoration pathways, including cover crops grown on restored land not used for conventional agriculture (e.g., cover crops used as feedstock in biogas plants), are eligible for a GHG bonus. WBA recommended consistent use of terminology throughout documents (e.g. agricultural use = cropland/perennial cropland) and the inclusion of examples.
Global Applicability and Recognition of Non-EU Emission Factor Models
Since ISCC PLUS is marketed and used as a global standard, WBA believes that ISCC should amend Section 2.2 to include an explicit, non-exhaustive list of accepted, widely used, peer-reviewed GHG calculation models deemed compatible with the referenced ISO standards in complement to the EU ones listed.
We would like to thank all members who contributed to this process.