In a significant step forward for climate cooperation in post-Brexit Europe, the European Commission and the United Kingdom have agreed to work towards linking their respective carbon markets—an ambition that signals renewed trust and deeper economic alignment amid broader bilateral cooperation talks. As outlined in the recent “Common Understanding” ahead of the UK-EU summit on 19 May 2025, the two sides are laying the groundwork for an integrated Emissions Trading System (ETS), a move that could reshape the future of carbon pricing, cross-border industry competition, and climate ambition on the continent.
A Turning Point in Carbon Market Integration
Article 392(6) of the EU-UK Trade and Cooperation Agreement (TCA) provided for the possibility of linking the United Kingdom Emissions Trading Scheme (UK ETS) and the European Union Emission Trading System (EU ETS). Nearly four years after the UK launched its standalone ETS, both parties now officially recognize that an ETS link could resolve pressing trade concerns, reinforce climate ambition, and support a more harmonized approach to industrial decarbonization.
The agreement, still in negotiation, would allow mutual exemptions from Carbon Border Adjustment Mechanisms (CBAM) for goods traded between the UK and EU, provided both markets meet equivalently ambitious environmental criteria. This would not only reduce trade friction but also eliminate double carbon pricing for companies operating across borders.
Material and Territorial Scope: Toward a Full-Fledged Link
The ETS linking agreement is envisioned to cover a comprehensive set of sectors, including:
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Electricity generation
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Industrial heat generation
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Heavy industry
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Maritime transport (both domestic and international)
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Aviation (domestic and international)
Critically, the inclusion of maritime and aviation marks a forward-looking approach aligned with the latest phase of EU ETS reform and ETS2 expansion. The material scope will be governed by a dynamic alignment mechanism, ensuring that UK carbon market rules remain functionally consistent with evolving EU legislation—subject to the UK’s constitutional and parliamentary constraints.
Any future expansion of sectors covered by the ETS link would be governed by a joint procedure, safeguarding both ambition and administrative flexibility.
Governance, Ambition, and Legal Oversight
To maintain coherence and transparency, the ETS link will include a joint governance framework. The United Kingdom is expected to contribute financially to the administrative functions of the European carbon market, reinforcing shared responsibility in climate regulation.
The UK cap and reduction trajectory will be guided by domestic legislation, notably the Climate Change Act and the UK’s Nationally Determined Contributions under the Paris Agreement. However, the agreement specifies that the UK’s ambition must be at least equal to that of the EU ETS.
In terms of dispute resolution, any legal question relating to EU law will ultimately remain under the jurisdiction of the Court of Justice of the European Union (CJEU), a sensitive but necessary concession to ensure the legal integrity of the EU framework.
Strategic Implications: Trade, CBAM, and Beyond
A functioning ETS link has broader implications than market alignment alone. With the EU and UK both developing CBAM frameworks, a bilateral ETS agreement would allow for reciprocal recognition of carbon pricing regimes, avoiding CBAM-related tariffs and compliance burdens on businesses.
This would be particularly relevant to high-emission sectors like steel, cement, and aluminum—sectors that are at the forefront of CBAM regulation and currently face uncertain cost exposures when operating across EU-UK borders.
Furthermore, harmonized carbon pricing reduces the risk of carbon leakage and strengthens the climate credibility of both jurisdictions in global negotiations. It could also support the competitiveness of clean technology investments and increase market liquidity by enabling cross-border allowance trading.
Technical and Regulatory Alignment: Hydrogen, CCUS, and Innovation
In parallel with carbon market integration, the UK and EU reaffirmed their commitment to technical cooperation in frontier climate technologies such as hydrogen, carbon capture, utilization and storage (CCUS), and biomethane. Regular exchanges on regulatory frameworks will facilitate standardization and deployment of these technologies across borders, supporting shared climate targets and industrial transformation.
This cooperation paves the way for joint investments, project interoperability, and coordinated incentives for decarbonization beyond the carbon market itself.
Conclusion: Toward a Unified Climate Policy Landscape
The renewed UK-EU climate agenda reflects a mature phase in post-Brexit relations—one that places strategic cooperation and environmental ambition above short-term divergences. The forthcoming ETS linking agreement, if finalized and implemented, could stand as one of the most consequential instruments for unified European climate action in the next decade.
In a global landscape increasingly characterized by fragmented climate policies and protectionist carbon measures, a unified carbon market across the English Channel offers a powerful counter-narrative—one based on shared standards, market trust, and climate solidarity.
As negotiations continue, the challenge will lie not in the ambition but in the operational details: ensuring legal coherence, respecting domestic procedures, and balancing sovereignty with strategic alignment. But the message is clear—on carbon markets and climate ambition, Europe is stronger together.