During a period of heightened regulatory uncertainty and persistent trade disruptions, the “clock is ticking” on emissions reporting in both the U.S. and EU, as critical deadlines approach rapidly. Carriers and shippers must prepare for overlapping compliance obligations that will fundamentally reshape maritime operations, say the authors of a report from emissions tracking firm, VesselBot, titled "Decoding Maritime Emissions, Q3 2025: Containership Emissions and Traffic on the Rise."

The study analysed 73,353 containership voyages completed by 4,750 vessels between July and September 2025, examining maritime performance across multiple dimensions — vessel size, age, shipbuilding origin, and specific trade.

Key findings include that there is stabilization in emission despite traffic growth. Total containership emissions reached 50.3 million tons in Q3 2025, remaining virtually unchanged (-0.2%) compared to Q3 2024 despite a 2.3% increase in voyages. Average well-to-wake emissions intensity improved to 195.9 g CO2e/TEU km, down 1.6% year-over-year, driven by longer steaming times and reduced port dwell times.

However, well-to-wake emissions intensity varies dramatically by vessel size, from 252.1 g CO2e/TEU km for Feeder vessels (up to 2,999 TEU capacity) to 61.4 for Very Large Container Ships (at least 17,000 TEU capacity). Feeder vessels completed 62.1% of all Q3 voyages yet accounted for only 10.3% of total TEU km, while VLCS completed just 2% of voyages, accounting for 17.2% of total TEU km, which reflects their significantly higher efficiency levels.

Further, analysis of route-specific performance variations demonstrates the importance of route-level analysis, with Asia-Northern Europe voyages averaging an intensity of 55.3 g CO2e/TEU km and a duration of 30.6 days. In contrast, industry-wide average steaming time was only 3.5 days, highlighting how aggregate metrics obscure critical operational differences.

"The regulatory landscape is growing more complex rather than simplified, as evidenced by the European Parliament rejection of the Omnibus simplification effort, and the IMO's postponement of the Net-Zero Framework," noted C. Komodromos, CEO & Founder of VesselBot. "With CBAM certification requirements beginning in weeks and Scope 3 reporting deadlines approaching, maritime stakeholders require granular, real-time data to navigate diverging compliance requirements across multiple jurisdictions. Industry averages fail to capture the significant performance variations between vessel sizes, ages, and routes that directly impact both compliance costs and operational efficiency."

The study analysed 73,353 containership voyages completed by 4,750 vessels between July and September 2025, examining maritime performance across multiple dimensions — vessel size, age, shipbuilding origin, and specific trade.

Key findings include that there is stabilization in emission despite traffic growth. Total containership emissions reached 50.3 million tons in Q3 2025, remaining virtually unchanged (-0.2%) compared to Q3 2024 despite a 2.3% increase in voyages. Average well-to-wake emissions intensity improved to 195.9 g CO2e/TEU km, down 1.6% year-over-year, driven by longer steaming times and reduced port dwell times.

However, well-to-wake emissions intensity varies dramatically by vessel size, from 252.1 g CO2e/TEU km for Feeder vessels (up to 2,999 TEU capacity) to 61.4 for Very Large Container Ships (at least 17,000 TEU capacity). Feeder vessels completed 62.1% of all Q3 voyages yet accounted for only 10.3% of total TEU km, while VLCS completed just 2% of voyages, accounting for 17.2% of total TEU km, which reflects their significantly higher efficiency levels. 

Further, analysis of route-specific performance variations demonstrates the importance of route-level analysis, with Asia-Northern Europe voyages averaging an intensity of 55.3 g CO2e/TEU km and a duration of 30.6 days. In contrast, industry-wide average steaming time was only 3.5 days, highlighting how aggregate metrics obscure critical operational differences.

"The regulatory landscape is growing more complex rather than simplified, as evidenced by the European Parliament rejection of the Omnibus simplification effort, and the IMO's postponement of the Net-Zero Framework," noted C. Komodromos, CEO & Founder of VesselBot. "With CBAM certification requirements beginning in weeks and Scope 3 reporting deadlines approaching, maritime stakeholders require granular, real-time data to navigate diverging compliance requirements across multiple jurisdictions. Industry averages fail to capture the significant performance variations between vessel sizes, ages, and routes that directly impact both compliance costs and operational efficiency."