2023 findings show some promise but many gaps remain. Join us in advancing the science.
Tackling greenhouse gas (GHG) emissions is a central priority for climate action – and understanding the role of sustainability systems in that effort is essential for guiding investments and policy. In 2023, Evidensia,
ISEAL and
Oxford Systematic Reviews (Oxsrev), as part of the
EU Horizon-funded STAR4BBS project, conducted a systematic evidence mapping of the impact of sustainability certification schemes and labels on GHG emissions across biobased value chains (1).
The evidence map – now peer-reviewed and publicly
available here – lays the groundwork for deeper analysis, while also revealing significant knowledge gaps across sectors, schemes, and stages of the value chain. To strengthen and update this work, we now call on researchers, certification bodies, and practitioners to contribute their published studies, impact evaluations, and monitoring reports to help close these gaps.
What does the evidence say?
From a rigorous review of over 6,500 records, 41 relevant articles were identified and analysed. A majority of these (30) reported a positive or negative impact of certification schemes on GHG emissions, with most using quantitative methods and some also including counterfactuals. However, the diversity in methodologies and limited data availability prevented meta-analysis or independent validation.
The agriculture sector is the most studied, especially organic systems, but generalisability across the sector and types of schemes was limited. Only three certification schemes – IFOAM, FSC, and RSPO – appear in more than 3 studies. While some schemes included GHG calculators (e.g. RSPO, MSPO, Bonsucro) evidence on their actual impact was sparse and context dependent.
Where are the gaps?
The review highlights multiple evidence gaps that must be addressed for the field to evolve:
- Geographic concentration: Most studies were focused on Southeast Asia and parts of Europe, leaving major gaps in South and East Africa, Central America, and specific producer countries such as India, Russia, and the Philippines.
- Sectoral gaps: Of the fifteen sectors mapped, only six had sufficient data. Notably under-researched on this topic were traditionally certified products like cocoa, bananas, tea, coffee, cotton, and sugarcane.
- Life cycle stages: Nearly all evidence related to production, with processing, use, and disposal phases rarely addressed – an important limitation given the full life cycle emissions of biobased products.
- Certification diversity: Only 16 schemes and labels were represented in the evidence base. Many widely used schemes had no or minimal publicly available impact research on GHGs specifically at that point in time.
- Measurement uncertainty: Few studies disaggregated individual GHGs (e.g. methane, nitrous oxide etc), and most converted values to CO2 equivalents – useful but potentially misleading without nuance.
- Theory of change: Many schemes addressed enabling conditions for emissions reduction but were unclear on causal pathways and their theories of change regarding direct GHG outcomes.
Why this matters now
The global and EU bioeconomy transition will increasingly rely on sustainability systems to track and incentivise low-emission practices. However, it is not yet possible to draw robust conclusions about which schemes are effective where, when, and under what conditions, using the publicly available evidence.
Contribute to the knowledge base
This 2023 mapping provides a critical foundation – but it is not definitive. To move forward, we invite researchers, certification scheme owners, and sustainability professionals to submit:
- Monitoring and evaluation (M&E) reports that focus on or include results on this issue
- Impact assessments of certification schemes and labels related to GHG emissions
- Other peer-reviewed or grey literature that looks at the links between VSS or other supply chain initiatives and GHG emissions
Submissions will be assessed for quality and relevance before inclusion in the Evidensia evidence library. Together, we can improve transparency, sharpen strategies, and build a more complete picture of what sustainability systems can deliver for climate mitigation.
Submit your work via the contact form or e-mail us directly via [email protected]
Access the full evidence map and related resources via our climate change topics.
(1) Note: To avoid overlaps with other EU-funded projects schemes and labels focusing solely on bio-based fuels were not included. Schemes covering feedstocks used for other sectors - such as sugarcane and wood - were included.