Certification criteria for low-ILUC-risk biomass pass, but barely, review finds

Indirect land use change, or ILUC, remains one of the most stubborn problems in the drive for sustainable bioenergy. When demand for biomass pushes agriculture to expand elsewhere, forests and other carbon-rich land can be converted indirectly, undermining the climate benefits the fuel was meant to deliver. Sustainability certification of low-ILUC-risk biomass is designed to manage this risk at the level of individual producers, but the practices used to qualify for such certification can themselves create side effects, from biodiversity loss to water pollution. A new review published in Energy, Sustainability and Society asks a question that has not been systematically answered before: are the criteria and indicators used in certification actually good enough to assess those trade-offs?

The study, led by Beike Sumfleth, Stefan Majer and Daniela Thrän, builds on an earlier review of the trade-offs that can arise when low-ILUC-risk practices are implemented. The team examined six selected trade-offs: atmospheric pollution, biodiversity loss, human disease, increased economic expenses, resource depletion and water pollution. For each, they inventoried potential certification criteria and indicators drawn from four kinds of documents: scientific journal articles, research project reports, publications of the International Social and Environmental Accreditation and Labelling Alliance, and the sustainability standard documents of biofuel certification schemes recognized by the European Commission or approved by the International Civil Aviation Organization.

The policy context matters here. Under the European Union’s Renewable Energy Directive, the European Commission has defined a low-ILUC-risk approach for certifying sustainable biofuels, with mandatory criteria set out in Implementing Regulation (EU) 2022/996. The approach remains applicable under RED III, which entered into force in November 2023 and allows high-ILUC-risk biofuels to be certified as low-ILUC-risk if their feedstock is produced using low-ILUC-risk practices. Separately, ICAO’s Carbon Offsetting and Reduction Scheme for International Aviation offers aircraft operators a low land use change risk mitigation approach within Sustainable Aviation Fuel certification, assigning zero land use change emissions to feedstocks that do not expand global agricultural land, to wastes and residues, and to certain high-yield algal feedstocks.

To judge the quality of the criteria and indicators, the researchers first defined a set of assessment requirements, drawing on literature about conceptually sound and practically applicable certification tools and supplementing this with guided expert interviews analyzed through thematic analysis. Seven experts from three of four expert groups responded. In total, 18 assessment requirements were used, ten concerning conceptual soundness and eight concerning applicability, each rated on a three-level scale of low, medium or high. Where a rating scale could not be developed, the team used what they call proxy quality assessment requirements. The criteria and indicators were then classified by relative and absolute ranking against these requirements, allowing the researchers to identify the quality level of what is currently in use and to single out potential best practice candidates.

The headline result is a qualified pass. Most of the currently used certification criteria and indicators, and most of the potential best practice candidates, meet the average quality level, suggesting they are appropriate to certify the potential trade-offs almost sufficiently. But that is a low bar, and the authors are explicit that there is still room for improvement and that more research on high-quality certification criteria and indicators is needed. Only a handful of exceptions scored above average: the criteria used in the 2BSvs and Better Biomass schemes for atmospheric pollution, and the criteria used in Better Biomass, REDcert and SURE for biodiversity loss, achieved overall scores barely above the average.

The picture varies considerably by trade-off. The majority of certification criteria for human disease, increased economic expenses, resource depletion and water pollution were rated low, and the criteria for assessing increased economic expenses were rated low for every single quality requirement, leading the authors to conclude that the economic criteria urgently need critical review. In contrast, criteria for atmospheric pollution and biodiversity loss were rated low in only about half of the schemes, with the rest receiving medium or high ratings. Among indicators, biodiversity loss indicators performed best, receiving medium or high ratings for the majority of assessment requirements, while indicators for atmospheric pollution, human disease and water pollution were rated low in about two thirds of cases.

Strengths and weaknesses follow a consistent pattern. About half of the criteria currently used for atmospheric pollution, biodiversity loss and human disease score medium or high for clarity, specificity and validity, and most indicators are highly rated for validity, meaning they rest on findings validated by scientific literature, recognized models or locally collected data. Yet almost all indicators score low for effectiveness, response time and audit interval, and low for baseline, data access, quantifiability, repeatability, scalability and verifiability. Most criteria lack defined system boundaries, require specialist knowledge or trained auditors, and lack guidelines explaining how verification should work in practice, leaving them insufficiently flexible across geographical scales.

Even the best practice candidates fall short of excellence. None of the highest-rated criteria and indicators achieved the maximum achievable scores; the best only barely exceeded the average. The strongest proposals came from the STAR-ProBio project reports across several trade-offs, alongside criteria from SURE and Better Biomass and indicators from Bonsucro and Traverso and colleagues. The best practice candidates score high on clarity, guidelines and validity, and typically specify system boundaries and reference recognized literature, but nearly all are rated low for auditor qualification, and all best practice indicators score low for response time, with most also low for audit interval, baseline, data access and verifiability. Their assessment is complex and labor-intensive, demanding specialist knowledge and costly data collection.

Comparing their results with a decade-old assessment by Meyer and Priess, the authors found both continuity and decline. Certification schemes still predominantly use driver, pressure or state indicators for biodiversity and water quality, and biodiversity indicators still demand auditors trained in fields such as ecology. But response time and audit interval ratings for biodiversity and water quality indicators are now significantly lower than ten years ago, and most biodiversity indicators no longer require a target or threshold value. The authors caution that the two studies differ in design, so these comparisons are illustrative examples rather than a systematic trend analysis. They also note a potential conflict of interest: the authors were involved in the STAR-ProBio project, whose criteria and indicators scored predominantly high, though they state they did not give those proposals preference.

The paper closes with concrete recommendations. Certification schemes are advised to implement best practice criteria and indicators, particularly for the poorly served trade-offs of increased economic expenses, water pollution, human disease and resource depletion; to favor tools requiring little specialized knowledge; to define system boundaries; and to establish indicators with immediate or at least annual reporting. Policymakers drafting sustainability requirements, including for EU RED III and CORSIA-eligible aviation fuels, are urged to require low-effort verifiers, develop good practice guidelines, define baselines and specify life cycle stage requirements. The authors conclude that the assessed criteria and indicators can be considered suitable for certifying the selected trade-offs, but that intensifying research and development of practical, evidence-based certification tools is necessary before low-ILUC-risk certification can rest on genuinely robust foundations.

Subject of Research: Quality assessment of certification criteria and indicators for trade-offs in low-ILUC-risk biomass certification

Article Title: How to assess trade-offs in sustainability certification of low-ILUC-risk biomass – current status and proposals for best practices

Article References: Sumfleth, B., Majer, S., & Thrän, D. (2026). How to assess trade-offs in sustainability certification of low-ILUC-risk biomass – current status and proposals for best practices. Energy, Sustainability and Society, 16(1), Article 51. https://doi.org/10.1186/s13705-026-00610-x

Image Credits: AI Generated

DOI: 10.1186/s13705-026-00610-x

Keywords: low-ILUC-risk biomass, sustainability certification, indirect land use change, biofuels, criteria and indicators, biodiversity loss, water pollution, RED III, CORSIA, best practices, certification schemes, assess