TNFD finalises Alternative Fuels guidance: WBA welcomes stronger recognition for biogas and biomethane as ISSB develops nature-related reporting 

In June 2026, the Taskforce on Nature-related Financial Disclosures (TNFD) published its final Additional Sector Guidance for Alternative Fuels, following consultation earlier this year. 

World Biogas Association (WBA) responded to the consultation because we saw an opportunity to strengthen how the guidance reflects the particular characteristics of anaerobic digestion (AD), which can produce renewable energy while also treating organic wastes, avoiding methane emissions from uncontrolled decomposition, recovering nutrients through digestate and producing useful co-products such as biogenic CO₂. Members were consulted during the refinement of our position.  

We therefore welcome a number of changes in the final guidance that reflect issues and recommendations raised by WBA during the consultation. In particular, the final guidance provides more comprehensive coverage of the biogas and biomethane sector, with stronger recognition of avoided methane emissions, biomethane upgrading, digestate and nutrient recovery, the appropriate application of the waste hierarchy, and proportionate traceability requirements for waste-derived feedstocks.

Recognising the wider value of methane avoidance 

One of the most important changes is clearer recognition of the environmental value created when organic wastes are diverted from unmanaged decomposition. 

During the consultation, WBA highlighted that the contribution of AD cannot be assessed solely through the renewable energy it produces. Where organic wastes would otherwise be landfilled, stored in open lagoons or allowed to decompose without adequate controls, their treatment through AD can also prevent methane emissions that would otherwise enter the atmosphere. 

We therefore welcome the introduction of the new AF.A2.2 metric. This allows companies to report environmental benefits associated with recovering waste and residue feedstocks, explicitly including avoided methane emissions and reduced pollution.

Greater recognition for biomethane upgrading and digestate 

The final guidance also gives greater visibility to valuable outputs from AD. It introduces AF.A2.1, a new metric measuring the amount and proportion of biogenic CO₂ captured during biomethane upgrading. 

Consideration of digestate was also improved through launching metric AF.A2.3, which measures the volume of digestate generated from biogas or alternative fuel production. Digestate is also identified alongside biogenic CO₂ and recovered heat as examples of waste streams that can be reprocessed into commercially useful co-products. This better reflects AD as a technology that can combine renewable energy production with nutrient recovery and wider resource efficiency. 

A more balanced approach to the waste hierarchy 

The treatment of the waste hierarchy is another area where WBA welcomes the changes made in the final guidance. The consultation draft relied primarily on the US EPA hierarchy; WBA recommended also recognising the EU Waste Framework Directive and avoiding overly rigid application where different treatment routes can deliver different overall environmental outcomes. 

The final guidance now draws on both approaches, more clearly distinguishes recycling and nutrient recovery from energy recovery and recognises that alternative uses may be appropriate where they demonstrably deliver better environmental outcomes. It also upgraded assessment of waste-derived feedstocks against waste hierarchy and cascading-use principles to a core sector metric, as WBA recommended, helping to highlight the wider environmental contributions of the biogas sector as a collective, rather than in isolation.  

We also support TNFD’s move towards a more proportionate approach to traceability. Rather than applying requirements designed for primary agricultural feedstocks equally to food waste, sewage sludge and processing residues, the final guidance allows waste-derived materials to use point-of-origin or collection-point traceability, supported where appropriate by recognised certification and mass-balance systems. This is closer to the risk-based approach advocated for by WBA in our consultation response.

Where we would welcome further development 

Alongside these changes, we were are also pleased to see several other issues raised in WBA’s consultation response reflected in the final document including broadening of TNFD’s treatment of pollutants, and greater clarity around reporting requirements and allocation between different outputs  

However, some areas remain where WBA would welcome further development. We continue to recognise the differences between primary biomass grown specifically for production and genuine wastes and residues when assessing land-use impacts. However, further consideration is needed regarding the specific characteristics of each feedstock (e.g. deforestation and conversion-free requirements are less relevant for MSW and sewage sludge waste streams). We would also welcome greater consideration of how reporting requirements can remain proportionate for smaller AD operators. WBA proposed greater use of proxy data, phased implementation, and a lighter-touch approach for smaller businesses. 

The final guidance moves in this direction by acknowledging that genuine wastes and residues can reduce pressures on land and natural resources. However, residues and biomass entering waste streams remain covered by the core spatial-footprint metrics, where deforestation and conversion-free requirements also continue to apply. More practical traceability options make these requirements easier to implement, but the conceptual issue raised by WBA has not been fully resolved.

What the final guidance means for the sector 

For biogas and biomethane operators, the final guidance reinforces the growing importance of robust evidence. 

Companies may increasingly need information on feedstock origin, the likely alternative fate of organic wastes, digestate production and use, captured biogenic CO₂, and certification or chain-of-custody arrangements. Nature-related reporting is also becoming increasingly location-specific, meaning generic lifecycle values will not always be sufficient on their own. 

For well-managed projects, this is also an opportunity – the biogas sector has long highlighted that the AD sector can provide several environmental services simultaneously. Reporting frameworks that are better able to capture methane mitigation, organic waste treatment, nutrient recovery, renewable energy production and resource efficiency together can make these contributions more visible to investors, customers and regulators. 

Why the ISSB transition makes this increasingly significant  

The relevance of WBA’s engagement with TNFD has also grown considerably since the consultation response was submitted.  

The International Sustainability Standards Board (ISSB) announced in November 2025 that it would develop its own approach to nature-related reporting, drawing extensively on TNFD’s work, including its recommendations, metrics and LEAP approach. 

Existing ISSB industry guidance already references biogas within its wider treatment of biofuels, but this remains relatively generic and is substantially shaped around liquid fuels and agricultural feedstocks. TNFD’s final Alternative Fuels guidance now goes considerably further in recognising characteristics directly relevant to AD and biomethane. 

There is no guarantee that individual TNFD metrics will ultimately be incorporated into the ISSB’s developing framework. Nevertheless, as international nature-related reporting increasingly builds on TNFD’s technical foundations, it is important that those foundations now provide a much more comprehensive representation of biogas and biomethane. 

WBA welcomes the progress made through the final Alternative Fuels guidance development process and will continue engaging constructively with TNFD, ISSB and other reporting bodies.  

Please contact the policy team at policysupport@worldbiogasassociation.org if interested in a more detailed benchmarking of the WBA recommendations against the changes made between the TNFD Additional Sector Guidance for Alternative Fuels draft and final publication.