Maritime emissions intensity falls to yearly low in Q4 2025

Maritime emissions intensity reached its lowest level of the year in the fourth quarter of 2025, reflecting improved operational efficiency across the global containership fleet, according to a new report by VesselBot.

The report shows that average well-to-wake emissions intensity declined to 188.9 grams of CO₂e per TEU-kilometre in Q4 2025, marking the lowest quarterly level recorded during the year. Total emissions for the quarter amounted to 52.4 million tonnes, generated across 79,438 containership voyages.

Operational efficiency improved as average time spent in port fell to 1.4 days, down 12.7% year on year, while average transit time stood at 3.3 days. Average vessel utilization remained stable at 69%, with vessels carrying an average of 2,735 TEU per voyage over an average distance of 2,063 kilometres. Average sailing speed increased to 13.4 knots.

Across full-year 2025, VesselBot tracked 313,690 voyages, producing total emissions of 208.8 million tonnes and transport work exceeding 2.9 trillion TEU-kilometres. Average emissions intensity for the year was 194.5 grams of CO₂e per TEU-kilometre, 1.4% lower than in 2024.

The report highlights significant differences by vessel size. In Q4 2025, feeder vessels recorded the highest emissions intensity at 244 grams of CO₂e per TEU-kilometre, while very large container ships averaged 65.2 grams, reflecting the efficiency advantages of scale on long-haul routes.

Vessel age also played a role. Ships aged up to five years achieved an average emissions intensity of 157.9 grams, a 17.2% year-on-year improvement, while vessels older than 20 years averaged 232.4 grams, well above the quarterly average.

Despite representing just 1.2% of total voyages, major fronthaul routes accounted for 12.1% of total Q4 emissions and 18% of transport work, underscoring the outsized impact of long-haul trades on overall emissions.

VesselBot concludes that the Q4 results reflect tangible gains in operational efficiency, driven by reduced port congestion, stable utilization, and optimized voyage execution, while emphasizing that emissions performance continues to vary widely by vessel size, age, and trade lane.