Across discussions, working towards interoperability of BCAs and underlying MRV systems was predominantly identified as one of the most important and feasible actions to be taken forward. This can be attributed to two main reasons. First, the benefits and common interests of international coordination in this space are broadly shared. Second, there is a unique window of opportunity to address this issue now. Once multiple regimes are fully in force, interoperability will be harder. Moreover, the announcement and gradual implementation of BCAs have increased attention around carbon pricing policies and related measures, thereby increasing “carbon literacy”[12] among policymakers and stakeholders around the world.
Participants also emphasised that many elements needed for greater coordination already exist, including technical knowledge gained from the implementation of ETSs in certain jurisdictions and various plurilateral initiatives that already work towards solutions in this field. At the same time, moving towards interoperability presents technical, political and co-ordinational challenges. Differences in system design, institutional mandates, and domestic interests could complicate alignment, while concerns around fairness and competitiveness influence the pace of cooperation and design of carbon border measures.
Going forward, discussions converged around a three-step approach towards mobilising political support for interoperability which can be summarised as: (1) taking stock of existing initiatives and identifying country champions to drive the issue forward at the international level, (2) facilitating inter-institutional cooperation, and (3) advancing concrete solutions through appropriate channels, for example by agreeing on guiding principles on MRV systems and carbon accounting methodologies, or by establishing common design principles for carbon border measures.
While much of the discussion focused on interoperability of carbon border measures and MRV systems, this pathway could also be applied to other identified opportunities, including strengthening MRV capacity building and demand-creation mechanisms to accelerate industrial decarbonisation, particularly in developing economies. Participants also emphasised potential feedback loops between different stages along the way, and that solely pursuing a top-to-bottom approach may not be desirable.
Taking stock: Mapping existing initiatives and identifying country champions
What is out there? Who could lead?
Participants underscored the importance of taking stock of existing initiatives and memberships across climate, trade, and carbon pricing fora as related efforts are already underway in platforms such as the Climate Club, WTO, IFCMA, and others. Discussions further emphasised the need to identify country champions willing and capable to drive this issue forward and generate the necessary political momentum.
Connecting the dots: facilitating inter-institutional cooperation
Who needs to be on board? Who could do what?
As a second step, discussions focused on strengthening coordination across current initiatives. Rather than creating new platforms, participants were in favour of connecting and building on existing ones – clarifying mandates and preventing duplication of workstreams and “technical inertia”.
Advancing concrete solutions: through appropriate channels
How can these channels be leveraged to advance practical solutions? How can carbon border measures be designed in an interoperable and inclusive manner?
Once suitable coalitions and venues for cooperation have been identified, more concrete policy solutions can be advanced through these channels.
In the context of interoperability, participants discussed developing voluntary guiding principles among key actors to provide a common reference point for cooperation. These were said to be procedural and non-prescriptive, and could serve as a starting point for more concrete implementation guidance on MRV systems and carbon accounting methodologies formulated with a broader set of stakeholders. An example that was discussed in this context is a proposal in the WTO Committee on Trade and Environment[13] on guidance on methodologies for measuring embedded emissions. The agreement on voluntary principles for action to address carbon leakage and other spillovers among members of the Climate Club[14] and the Open Coalition on Compliance Carbon Markets[15] were mentioned as recent initiatives that could be leveraged to advance cooperation on interoperability.
Drawing on existing analytical work, for instance the stakeholder dialogues convened by the International Institute for Sustainable Development[16], participants also suggested that an agreement on best practices for BCA design could support countries that want to implement carbon border measures in “getting it right” while reducing fragmentation. Greater clarity was considered desirable in several areas, including the treatment and calculation of default values, the inclusion of indirect emissions, potential scope expansion further down the value chain, de minimis thresholds and the interaction between border measures and export rebates.
[12] With the term “carbon literacy”, a participant referred to the growing awareness among stakeholders of the economic implications of GHG emissions and policy tools available to address them. Discussants noted that emerging border carbon measures have served as a catalyst for carbon pricing discussions, incentivising the strengthening or adoption in many jurisdictions.
[13] https://docs.wto.org/dol2fe/Pages/SS/directdoc.aspx?filename=Q:/WT/CTE/W269R1.pdf&Open=True
[14] https://climate-club.org/wp-content/uploads/2025/09/principles_explanatory_note.pdf
[15] https://www.gov.br/mre/pt-br/canais_atendimento/imprensa/notas-a-imprensa/declaracao-sobre-a-coalizao-aberta-de-mercados-regulados-de-carbono/OpenCoalitiononComplianceCarbonMarkets.pdf
[16] https://www.iisd.org/system/files/2025-07/border-carbon-adjustment-guidance.pdf