EU’s climate objectives need data for policy and research

As the EU Emissions Trading System (EU ETS) plays an important role in delivering the EU’s climate objectives, by covering around 40% of the EU’s total GHG emissions, assessing its effectiveness is key to ensure it can meet these objectives. High-quality, accessible, and interpretable data are critical to this task, as it underpins the analysis, monitoring and evaluation of the system. Fragmented or difficult-to-use data can therefore become a binding constraint on evidence-based policymaking.

Against this background, the Florence School of Regulation hosted an online debate on Overcoming fragmentation: improving EU ETS data for policy and research.

Despite recent progress, key challenges persist: EU ETS-related data remain dispersed across multiple sources; the EU Transaction Log (EUTL) was not originally designed with transparency or research use in mind; and linking registry information with external datasets on installations, firms or financial actors remains technically demanding.

Strengthening EU ETS data

The debate was framed by work conducted at the FSR under the LIFE COASE project, which aims to strengthen the scientific assessment of the EU ETS and foster dialogue between regulators, researchers, NGOs and industry. A central focus of the project is improving the data infrastructure of the EU ETS. This includes integrating data by linking the EUTL with external datasets, such as ENTSO-E for power plants, IEP for industrial installations, and Orbis for financial entities. A second stream of work focuses on structuring the information contained in the EUTL. The EUTL data is indeed rich but not always straightforward to interpret. Cleaning and organising it is essential for understanding market behaviour and regulatory coverage. This work included identifying installation entry and exit years and clarifying the information contained in the transaction table, both of which are essential for analysing market dynamics and regulatory coverage. These efforts directly address common challenges faced by analysts, including entity mapping across heterogeneous datasets and interpretation of registry records. The different data outputs related to the COASE project were presented during the final conference of the project: Conference on evidence-based climate policy.

Remaining challenges

Panellists from academia, policy, and independent think tanks examined the persistent challenges surrounding EU ETS data, including fragmentation across multiple sources, the complexity of the EU Transaction Log (EUTL), and the technical difficulties of linking registry information with external datasets. The speakers highlighted how these limitations can hinder policy evaluation, market monitoring and academic research at a time when robust analysis is essential to support the EU’s net-zero ambition (the featured presentations can be found here).

Jan Abrell (University of Basel) discussed long-standing challenges and recent progress in making registry data more usable for research, drawing on his experience with EUETS.info and the data enhancements he contributed during the COASE project. He called for a more community-based effort to strengthen data improvement and stressed the importance of tracking registry data dynamically, to retrieve a panel structure that allows ownership changes to be followed over time.

Aliénor Cameron (OECD, EUI) reflected on three key areas for data improvement: connecting emissions from installations to output data to better understand emissions intensity, moving from process-level to the product-level emissions reporting, and providing more disaggregated emissions data at the sub-installation level.

Liza Leimane (EEA) provided insights into how EU ETS data are collected and used for official monitoring, focusing on Member State reporting obligations, the implementation of MRV systems, and the use of ETS auctioning revenues. The annual trends and projections of the EU ETS report was also presented.

Meili Vanegas Hernandez (Sandbag) highlighted the importance of transparent, well-structured data for independent analysis and civil-society scrutiny. Drawing on an exercise tracking emissions in the iron and steel sector, she stressed the importance of consolidating the installation-level activity at the sectoral level systematically to enable meaningful analysis.

Looking ahead

The debate underscored the shared need for improved transparency, compatibility and accessibility of EU ETS data to support effective climate policy. Strengthening the data foundations of the EU ETS is not only a technical exercise, but a necessary condition for credible carbon market governance, robust policy evaluation and informed public debate.

The FSR will continue to work on enhancing EU ETS data and monitoring the functioning of the carbon market through its ongoing research and policy activities. In this context, encouraging a community-based ecosystem around EU ETS data can help ensure continuity, reproducibility and innovation in policy-relevant analysis, by enabling researchers, public institutions and independent analysts to collectively contribute to improving data quality, consistency and usability.