No room for evasion: strengthening the maritime ETS to protect climate and competitiveness

This briefing looks at a particular type of carbon leakage from the Maritime ETS, ‘evasive’ port calls, and proposes targeted regulatory adjustments to prevent carbon leakage risks. ‘Evasive’ port calls can take place if vessels insert an additional port call in a neighbouring non-EU port in order to shorten the ETS-relevant leg of a voyage and reduce ETS liability. Initial analysis led by the European Commission in March 2025 did not find systemic evidence of such behaviour, but monitoring continues.

Overall observed traffic patterns since ETS implementation do not indicate systemic or structural evasive port calls. Analysis comparing pre-ETS (2023) and post-implementation (2024) traffic across Atlantic, Mediterranean, and North European regions reveal mixed trends. While certain routing adjustments are observable, they do not constitute clear evidence of widespread systematic ETS-driven evasion.

Regional evidence is mixed and inconclusive regarding deliberate evasive port calls. In 2024, Atlantic EU ports saw fewer overall calls but more direct arrivals from distant, low-risk non-EU ports, suggesting no systematic addition of ports calls in nearby non-EU ports to evade the ETS. In the Eastern Mediterranean, there is some evidence of changes to port stop patterns, though rerouting linked to Red Sea disruption is a credible alternative explanation. In both the Western Mediterranean and North European ports, routing patterns remained broadly stable despite a slight decline in overall voyage numbers, with no clear evidence that ships made new evasive port calls. Although these changes do not prove evasion, they indicate that incentives may emerge in the future.

Targeted regulatory adjustments can remove emerging incentives without overhauling the ETS framework. The briefing proposes expanding the current port list to include more non-EU ports located within and beyond 300 nautical miles of an EU port, and lowering the transhipment activity threshold from the 65% currently in place. This could remove potential incentives to re-route by calling at currently non-listed ports as the scope of the ETS expands to 100% of liable emissions in 2026. In addition, an “ETS-as-a-service” clause would ensure that a share of the ETS revenues generated from voyages involving neighbouring non-EU ports is redistributed to those countries. This mechanism would discourage rerouting while enhancing cooperation and strengthening political acceptability.

The inclusion of smaller vessels can be done through simplified reporting. This briefing proposes to split the reporting between ETS 1 and ETS 2 based on operational patterns (e.g. small ships would fall under ETS2 if they engage in 80% EU-based voyages). This would minimise administrative burden by placing compliance upstream at the fuel supplier level for ships falling under ETS2. In addition, a simplified monitoring and reporting system focused on annual fuel consumption and CO₂ emissions would ensure proportionality while preserving environmental integrity.