Emissions Leaderboard

Method & caveats

• cAER is the capacity-normalised annual efficiency ratio — grams of CO₂ per deadweight-tonne·nautical-mile. It is the carbon a ship emits to move a tonne of cargo capacity one mile, so it is comparable across ship sizes within a segment. Lower is cleaner.
• Measured only. Every ship on this ladder carries a verified reported figure. The modelled (imputed) bands for the non-reporting fleet are deliberately excluded — it would be dishonest to rank a model-guessed band against an audited report. The whole-fleet imputed coverage lives on the carbon-intensity page instead.
• Latest year per ship. A vessel reporting more than one year is carried once, at its most recent reported year, so the ladder is current and no ship double-counts. Because ships last reported in different years, the ladder mixes vintages — the “latest reporting year” stat is the most recent year present, not a year every ship shares, so cAER here compares figures across reporting years. Each ship's own year is in the Year column.
• The A–E band is OUR peer-relative efficiency proxy (recomputed across the reporting cohort), not the official IMO CII rating. It may be blank where a report carried an AER but no band.
• Anchor artefacts excluded. A ship that barely sailed reports a near-zero distance denominator that inflates its cAER into the thousands — those are non-sailing artefacts, not genuine laggards, so the cron clips them at the same physical ceiling its segment means use before ranking.
• Segments use the platform's single shared vessel-class classifier over the reported ship type.