CO₂ emissions reported by maritime transport under the European MRV system—which covers ships of 5,000 GT or more calling at ports in the European Economic Area—increased by 9.6% in 2024, reaching 140.5 million tonnes. This rise reverses the decline recorded in 2023 and can largely be attributed to route diversions caused by geopolitical tensions in the Red Sea, which forced many vessels to sail around Africa, thereby increasing voyage duration and fuel consumption.
Emissions subject to the European Emissions Trading System (ETS) amounted to 83.7 million tonnes in 2024. Based on the average carbon allowance price for that year, this would have represented an estimated cost of approximately €2.2 billion for the maritime sector in the first year of the system’s implementation.
This figure is expected to rise in 2025, as shipping companies will be required to surrender allowances for 70% of their emissions, up from 40% in 2024. In addition, the average price of emission allowances increased by 11.4% in the first half of 2025 compared to the same period the previous year, further raising the financial impact of the measure on the sector.
