Most Emission-Efficient Container Ships
Ships ranked by AER (Annual Efficiency Ratio) — grams of CO₂ emitted per tonne of deadweight carried one nautical mile (g CO₂/dwt·nm), the IMO carbon-intensity metric behind the CII rating — from official EU MRV emissions data for reporting year 2025. Lower is greener. Pick a segment and size class to see the greenest vessels first.
| # | Vessel | Size (TEU) | Built | Carbon intensity — AER (g CO₂/dwt·nm) | Grade |
|---|---|---|---|---|---|
| 51 |
MSC SIENA
IMO 9987275
|
16,000 TEU | 2024 |
3.8
|
A |
| 54 |
MSC ALESSIA
IMO 9987330
|
16,000 TEU | 2025 |
3.8
|
A |
| 53 |
ONE FORWARD
IMO 9936422
|
15,500 TEU | 2024 |
3.8
|
A |
| 52 |
MSC THAIS
IMO 9957347
|
15,600 TEU | 2021 |
3.8
|
A |
| 55 |
HMM DUBLIN
IMO 9863314
|
23,000 TEU | 2020 |
3.8
|
A |
| 56 |
MSC ISABELLA
IMO 9839272
|
22,000 TEU | 2019 |
3.8
|
A |
| 57 |
ONE FANTASTIC
IMO 9936381
|
15,500 TEU | 2023 |
3.8
|
A |
| 58 |
ALVA MAERSK
IMO 9961817
|
16,592 TEU | 2025 |
3.8
|
A |
| 59 |
CMA CGM PALAIS ROYAL
IMO 9839181
|
22,448 TEU | 2020 |
3.8
|
A |
| 61 |
MARIT MAERSK
IMO 9632167
|
18,340 TEU | 2011 |
3.9
|
A |
| 60 |
CMA CGM COBALT
IMO 9996680
|
147,196 | 2025 |
3.9
|
A |
| 63 |
ONE INTELLIGENCE
IMO 9933121
|
24,000 TEU | 2023 |
3.9
|
A |
| 62 |
HMM HAMBURG
IMO 9863338
|
23,000 TEU | 2020 |
3.9
|
A |
| 65 |
HMM ST PETERSBURG
IMO 9868364
|
23,000 TEU | 2020 |
3.9
|
A |
| 64 |
MSC FLORA
IMO 9978937
|
11,400 TEU | 2022 |
3.9
|
A |
| 66 |
OOCL FELIXSTOWE
IMO 9922512
|
23,000 TEU | 2023 |
3.9
|
A |
| 67 |
MSC AUDREY
IMO 9540065
|
15,128 TEU | 2023 |
3.9
|
A |
| 68 |
ONE FUTURE
IMO 9936393
|
15,500 TEU | 2024 |
3.9
|
A |
| 69 |
ALETTE MAERSK
IMO 9948774
|
16,592 TEU | 2024 |
3.9
|
A |
| 71 |
HMM ROTTERDAM
IMO 9868338
|
23,000 TEU | 2020 |
3.9
|
A |
| 70 |
CMA CGM JACQUES SAADE
IMO 9839179
|
22,448 TEU | 2020 |
3.9
|
A |
| 74 |
BEIJING MAERSK
IMO 9984572
|
17,148 TEU | 2025 |
3.9
|
A |
| 73 |
HMM LE HAVRE
IMO 9868314
|
23,000 TEU | 2020 |
3.9
|
A |
| 75 |
ONE STORK
IMO 9784788
|
14,000 TEU | 2018 |
3.9
|
A |
| 72 |
OOCL PIRAEUS
IMO 9908097
|
23,000 TEU | 2023 |
3.9
|
A |
| 76 |
HMM GDANSK
IMO 9863326
|
23,000 TEU | 2020 |
3.9
|
A |
| 80 |
MSC CARMELITA
IMO 9946879
|
16,000 TEU | 2024 |
3.9
|
A |
| 77 |
ONE TRIBUTE
IMO 9769295
|
20,170 TEU | 2017 |
3.9
|
A |
| 79 |
MSC ELENOIRE
IMO 9962603
|
202,562 | 2024 |
3.9
|
A |
| 78 |
MSC ILARIA
IMO 9962586
|
202,562 | 2024 |
3.9
|
A |
| 81 |
MSC MAURA
IMO 9962536
|
202,562 | 2024 |
3.9
|
A |
| 82 |
MSC FATMA
IMO 9927251
|
14,812 TEU | 2022 |
3.9
|
A |
| 84 |
HMM OSLO
IMO 9868326
|
23,000 TEU | 2020 |
4.0
|
A |
| 83 |
ONE MEISHAN
IMO 9805465
|
14,000 TEU | 2018 |
4.0
|
A |
| 85 |
HMM HELSINKI
IMO 9863340
|
23,000 TEU | 2020 |
4.0
|
A |
| 86 |
CMA CGM ARCTIC
IMO 9867841
|
15,128 TEU | 2022 |
4.0
|
A |
| 87 |
ONE TRIUMPH
IMO 9769271
|
20,170 TEU | 2017 |
4.0
|
A |
| 89 |
HMM COPENHAGEN
IMO 9863302
|
23,000 TEU | 2020 |
4.0
|
A |
| 88 |
ONE TRUST
IMO 9769283
|
20,170 TEU | 2017 |
4.0
|
A |
| 91 |
MSC GRACE
IMO 9987366
|
16,000 TEU | 2025 |
4.0
|
A |
| 90 |
HMM SOUTHAMPTON
IMO 9868340
|
23,000 TEU | 2020 |
4.0
|
A |
| 94 |
ROTTERDAM EXPRESS
IMO 9943891
|
23,660 TEU | 2025 |
4.0
|
A |
| 93 |
ONE TRUTH
IMO 9773210
|
20,150 TEU | 2017 |
4.0
|
A |
| 92 |
OOCL ZEEBRUGGE
IMO 9908140
|
24,000 TEU | 2020 |
4.0
|
A |
| 97 |
EVER ECO
IMO 1025203
|
16,500 TEU | 2023 |
4.0
|
A |
| 98 |
ANGELICA MAERSK
IMO 9948798
|
16,592 TEU | 2021 |
4.0
|
A |
| 96 |
MATHILDE MAERSK
IMO 9632179
|
18,340 TEU | 2015 |
4.0
|
A |
| 95 |
OOCL SWEDEN
IMO 9922603
|
24,000 TEU | 2024 |
4.0
|
A |
| 99 |
MSC SAN FRANCISCO
IMO 9987328
|
16,000 TEU | 2025 |
4.0
|
A |
| 100 |
BUSAN EXPRESS
IMO 9540144
|
23,660 TEU | 2024 |
4.0
|
A |
Which engines power the greenest fleets?
The main engine is the single largest CO₂ source on board — typically well over 80% of a ship's emissions come from propulsion. We aggregated this ranking the other way around: every engine design is scored by the measured carbon intensity of the vessels carrying it, licensee-built units merged under their design brand. The verdict from the 2025 data — modern dual-fuel designs like MAN B&W's ME-GI and WinGD's X-DF families, together with EGR/SCR-abated and ultra-long-stroke G-type engines, consistently power the most emission-friendly ships in service.
AER (Annual Efficiency Ratio) = annual CO₂ emissions ÷ (deadweight × distance sailed), the IMO carbon-intensity metric used for CII ratings. It is built only from measured CO₂, distance and deadweight — not the self-reported cargo transport-work figure, which is unreliable. Implausible outliers (top 2% per segment) are excluded. Grade A–E reflects each vessel's rank within its segment. Source: EMSA THETIS-MRV.