BPA: UK Box Growth Doesn't Prove EU ETS Carbon Leakage

BPA Pushes Back on Carbon Leakage Claims

The British Ports Association (BPA) has disputed the idea that rising UK container volumes are evidence of carbon leakage caused by the EU Emissions Trading System (EU ETS). According to a report by Ship & Bunker, the BPA’s position directly contradicts claims made by Spain’s EU ETS Observatory, which has pointed to UK port growth as a sign that shipowners are rerouting cargo away from continental Europe to avoid carbon costs.

In a report released last week, the BPA noted that UK container tonnage climbed 10%, or 6.2 million tonnes, in 2025. Of that increase, London alone accounted for 5.4 million tonnes, a jump the association links largely to the opening of London Gateway’s fourth berth in November 2024, a £350 million investment. The BPA argues this is a far more plausible explanation for the growth than any shift in cargo driven by EU carbon pricing.

Continental Ports Also Grew

Crucially, the BPA pointed out that major EU ports — Rotterdam, Antwerp-Bruges, Hamburg and Le Havre — also posted higher container throughput in 2025. If EU ETS costs were genuinely pushing cargo out of the bloc and into UK ports, the association argues, continental hubs would be expected to show stagnation or decline rather than growth of their own. The simultaneous rise across both UK and EU ports undercuts the simple leakage narrative.

The BPA also took aim at the methodology behind the leakage claims, specifically criticizing the use of TEU-miles as a measure. It argued this metric captures vessel capacity and the distance a ship sails rather than how much actual cargo is being moved, making it a poor proxy for determining whether cargo volumes are genuinely shifting between regions because of carbon pricing.

Multiple Factors, Not Just Carbon Pricing

The association did not dismiss EU ETS costs entirely. It acknowledged that carbon pricing could factor into individual routing decisions made by carriers. However, it maintained that current evidence does not support carbon pricing as the main driver behind UK container growth. Instead, the BPA highlighted port investment, changes in shipping alliance networks, and congestion as more likely explanations for shifting traffic patterns.

Based on these findings, the BPA has called on both the UK government and the European Commission to re-examine the evidence before pursuing any regulatory measures aimed at British ports over alleged carbon leakage.

Regulatory Backdrop

The dispute sits against a backdrop of expanding carbon regulation in maritime transport. The EU ETS was extended to cover shipping from January 1, 2024. More recently, the UK’s own Emissions Trading System began covering eligible domestic maritime activity for ships of 5,000 GT and above from July 1, 2026. With both schemes now operating in parallel, questions about whether carbon costs are reshaping trade flows between the UK and EU are likely to persist.

What This Means for Owners and Operators

For ship owners, managers and charterers, this debate is a reminder that port-calling and routing decisions are rarely driven by a single factor. Berth availability, terminal capacity upgrades, alliance restructuring and congestion can all move volumes between ports just as much as — or more than — a carbon cost differential. Attributing commercial routing shifts to any one regulatory driver without examining the full operational picture risks misreading the market.

As EU ETS and UK ETS compliance costs continue to feed into voyage planning and commercial negotiations, owners and operators should ensure their own cost and emissions data is accurate and defensible, rather than relying on broad traffic statistics to justify routing or chartering decisions. Independent verification of vessel performance, fuel consumption and voyage data can help owners build a clearer, evidence-based picture of their actual compliance exposure — the kind of technical due diligence covered by marine technical consultancy services — rather than relying on aggregate port statistics that may not reflect vessel-specific realities.