The 8,525 ships the chart has no row for

Dark navy briefing slide, masthead “Port decarbonisation desk · ships calling at EEA ports” on the left and “EU maritime MRV returns · reporting year 2023” on the right, headlined “Twelve thousand ships call here, and five types are four fifths of them.” Beneath the headline sits a bordered chip reading “Demonstration · drawn by us from published figures”. A standfirst says every figure is the European Commission’s own published summary of the 2023 returns under the EU Maritime MRV Regulation — verified by accredited verifiers, flag-neutral, one reporting year, one method; that 12,344 ships filed an emissions report for 2023 and together emitted 126.7 million tonnes of CO₂ on voyages to, from and between ports of the European Economic Area; that reporting is mandatory and every return is checked by an accredited verifier before publication, so nothing has been sampled, smoothed, indexed or rescaled; that the axis is linear, zero-based and evenly ticked and the shares are the Commission’s own at the precision it published them; and that the Commission publishes these figures in prose and in its own charts while the bars are ours. The main panel, headed “The fleet that calls at EEA ports, 2023” and subtitled “Share of the 12,344 ships filing an emissions report, by ship type · the five named types and the ten others · zero-based linear axis, evenly ticked, unbroken · shares as published”, is a horizontal bar chart on an axis running 0% to 50% in even steps of 10: bulk carriers 29%, oil tankers 15%, container ships 15%, chemical tankers 11%, general cargo ships 9%, and a sixth bar in a darker gold for the other ten reporting types at 21%. A caption reads “Shares as published · every ship in the 2023 register · one scale throughout”. A second panel, “And where that fleet’s carbon is”, draws the 126.7 Mt of reported CO₂ as one stacked bar: container ships 28%, oil tankers and bulk carriers 24%, the other twelve reporting types 48%, with a line beneath noting the top three ship types together at 52% of reported CO₂, bulk carriers alone at 11% — their lowest share on record — and 41 million tonnes of fuel burned by the reporting fleet. A third panel, “What each ship reports”, lists in two monospaced columns what a return carries — fuel consumed by fuel type, CO₂ emitted at sea and at berth, distance travelled and time at sea, cargo carried and transport work — alongside what is derived and published with it: average energy efficiency (EEOI, AER), technical efficiency (EEDI or EIV), ship type, deadweight and gross tonnage, and the verifier and company by name; a note says coverage is voyages to, from and between EEA ports plus emissions at berth, and that methane and nitrous oxide join the return from 2024 while the 2023 year reported here is CO₂ only. Six cards run down the right. “The fleet, in one figure” prints 12,344 ships in large type and says they filed for 2023, the second-highest count since the register opened in 2018 and 5.4% below 2022, reporting 126.7 Mt of CO₂, 7.9% less than in 2022 and about 13% below the pre-pandemic years. “Read-out for the desk” says five ship types are 79% of the arrivals and the top three are 52% of the carbon, that bulk carriers, tankers and container ships are the fleet, that no other named ship type on either chart reaches a tenth of it and small craft do not register at all, and recommends pointing the shore-power and berth-emission programme at the container terminals and the tanker and bulk berths because a small-craft programme has nothing on this evidence to aim at. “What the register is” explains that under the EU Maritime MRV Regulation ships above 5,000 gross tons monitor and report fuel use and CO₂ for voyages to, from and between EEA ports including emissions at berth, that the rule is flag-neutral, and that every report is checked by an accredited verifier before publication ship by ship in EMSA’s THETIS-MRV. “The five and the ten” tabulates the shares. “How the year moved” notes that twelve of the fifteen reporting ship types emitted less in 2023 than in 2022, bulk carriers falling furthest at 4.5 Mt or 23% with 12% fewer active, container ships down 6% while about 2% more of them reported, and passenger ships up 6% to their highest since 2018. “Basis of measurement” credits the European Commission’s 2024 Report on CO₂ Emissions from Maritime Transport, SWD(2025) 38 final of 12 February 2025 — the sixth annual report, covering the 2023 reporting year under Regulation (EU) 2015/757 — with shares and totals as published, notes that the exact count of reporting ships is the 2023 MRV data extract of 19 September 2024 as cited in the Commission’s supporting study while the annual report itself rounds it to “almost 12,300”, and gives a retrieval date of 11 September 2026. A method line runs along the foot: published figures as reported; one reporting year, one method; verified returns, flag-neutral; zero-based linear axis, evenly ticked; nothing sampled, smoothed or rescaled. A footnote credits the source and states that this slide is a demonstration drawn by us in the manner of a port authority’s decarbonisation briefing — the desk, the read-out and the recommendation are invented, and every figure behind them is real. — Showing the misleading chart

The same year on a cream background, kicked “The same reporting year · the same published figures · the line put back on the chart” and “Vessels 400–4,999 GT calling at EU ports · 2023”, headlined “The 8,525 ships the chart has no row for.” A standfirst says nothing on the briefing slide is bent — its axis starts at zero, its shares are the Commission’s own, reporting is compulsory and every return behind it was verified — and that the words doing the work are “in scope”: the EU Maritime MRV Regulation collects from ships above 5,000 gross tons, so the register is a census of what clears a line rather than of what calls at a port; that below that line the study DG CLIMA commissioned counts 8,525 vessels of 400–4,999 GT calling at EU ports in 2023, 69.1% as many ships as the register holds, emitting an estimated 18.99 Mt of CO₂ or 15.0% of the reported total; and that these are not small bars but no bars at all, because a missing row reads as a zero. The first panel, “The two tiers, one scale”, sets both tiers against one zero-based axis in two pairs: by vessels, in the register (≥5,000 GT) 12,344 against below the line (400–4,999 GT) 8,525; by CO₂ in million tonnes, in the register 126.70 against below the line 18.99, the lower bar of each pair drawn in orange-red. Its caption says the missing tier is 69.1% as many vessels and 15.0% as much CO₂ as the register holds, that this is the whole mechanism — a line drawn to catch tonnes catches them, leaving the register with about 87% of the CO₂ counted here while the same rows read as a count of ships hold 59% — and that the Commission’s own “around 90%” and “around 55%” are the same arithmetic over a wider universe, since they also count ships below 400 GT, which are in neither total on the page. The main panel, headed “What is below the line, by category” and subtitled “Vessels of 400–4,999 GT calling at EU ports, 2023 · sorted by number of vessels · zero-based linear axis · estimated CO₂ printed beside each bar · none of these vessels is counted in any row on the first slide”, is a horizontal bar chart on an axis running 0 to 3,000 in steps of 500: general cargo 2,296 vessels and 4.26 Mt, miscellaneous–fishing 1,065 and 2.30 Mt, offshore 921 and 3.41 Mt, yacht 896 and 1.45 Mt, chemical tanker 756 and 2.21 Mt, ferry–RoPax 571 and 1.57 Mt, service–tug 385 and 0.49 Mt, service–other 349 and 0.77 Mt, oil and product tanker 256 and 0.38 Mt, ferry–passenger only 253 and 0.34 Mt, cruise 217 and 0.56 Mt, miscellaneous–other 154 and 0.12 Mt, liquefied gas tanker 143 and 0.44 Mt, bulk carrier 111 and 0.27 Mt, refrigerated bulk 53 and 0.14 Mt, other liquids tankers 42 and 0.11 Mt, container 38 and 0.13 Mt, and ro-ro 20 and 0.04 Mt. A key colours the bars three ways: blue for the categories that join the register in 2025 by a rule already agreed, general cargo and offshore, 3,217 vessels and 7.67 Mt; gold for those held out by the tonnage line alone, 2,460 vessels and 6.19 Mt; orange-red for those out of scope by type or activity at any tonnage — fishing, yachts, tugs, service craft and miscellaneous vessels, 2,849 vessels and 5.13 Mt. A third panel, “Both of the first slide’s charts, with the tier put back”, recomputes each of them over everything counted on the page, 20,869 vessels and 145.69 Mt against the register’s 12,344 and 126.70 Mt: a stacked bar and table for carbon give container ships 28% rebased to 24.4%, oil tankers and bulk carriers 24% to 20.9%, below the line nothing to 13.0%, and the other twelve types 48% to 41.7%; a second table gives the share of ships as the slide drew it against the rebased figure — bulk carriers 29% to 17.7%, oil tankers 15% to 10.1%, container ships 15% to 9.1%, chemical tankers 11% to 10.1%, general cargo ships 9% to 16.3%, the five together 79% to 63.3% — beside a note saying the briefing’s headline is a claim about counts, that counts are what a tonnage line takes apart, that general cargo moves from fifth to second because 2,296 of the vessels left out are general cargo ships, and that the counts behind the rebased column are implied by the published shares, rounded to whole points, so each carries about ±60 ships while the ranking survives comfortably. Its caption adds that on carbon the tier is 15.0% of the register and 13.0% of everything counted here, wider either way than every named ship type but container ships. Eight cards run down the right. “Where the line came from” says the threshold is not a measurement: the 2013 impact assessment costed the paperwork at about EUR 5,545 per vessel per year if every ship above 400 GT reported against EUR 4,479 if only ships above 5,000 GT did — the 2013 figures brought to 2023 prices by the study on a GDP deflator of 1.28 — and smaller vessels were left out on grounds of administrative burden and proportionality, a reasonable decision about forms that silently became the edge of the data. “The publisher says so, in its own report” quotes the Commission: “Despite limiting monitoring requirements to large ships (above 5 000 GT), the Regulation covers around 90% of all CO₂ emissions in the EU maritime transport sector, whilst only including around 55% of all ships calling into EEA ports,” notes that one sentence carries two numbers that are not the same number, and explains that its 55% sits a little under the 59% on the left-hand panel because the Commission counts against a wider universe, taking in ships below 400 GT. “Why both can be true” gives the average vessel in the register 10,264 t of CO₂ in 2023 against about 2,228 t below the line, a fifth as much, and says ships big enough to clear a tonnage line are exactly the ships that carry most of the tonnes, which is why the rule works for carbon and fails for counting. “If the missing tier were a ship type” notes that 18.99 Mt is 15.0% of the register’s reported CO₂ while the Commission puts container ships at 28% and bulk carriers at 11% with the top three together at 52%, leaving oil tankers around 13%, so the tier would sit second among the named types on the first slide’s other chart. “Three different ways to be absent” says the tier divides exactly three ways and that the study’s own scenario arithmetic draws the lines: 2,460 vessels and 6.19 Mt held out by tonnage alone, which would report if the line moved; 2,849 vessels and 5.13 Mt out of scope by type or activity whatever their size, since fish-catching and fish-processing ships are excluded by name and tugs, service craft and private yachts carry neither cargo nor passengers commercially; and 3,217 vessels and 7.67 Mt already on their way in for 2025 — with everything under 400 GT, and the military vessels and naval auxiliaries, below all three and in neither chart on the page. “The line has already moved once” says that from 2025 small general cargo and offshore ships report too, 3,217 vessels and 7.67 Mt crossing into the register, 38% of the tier’s vessels and 40% of its carbon, because a rule changed rather than because anything sailed differently, leaving 5,309 vessels outside — 43.0% of the register’s ship count — and 11.32 Mt, or 8.9% of its CO₂. “What to draw instead” says to put the eligibility rule in the caption the way you print a unit, draw the line on the chart, give an estimated tier a bar of its own and label it an estimate, say in words where no estimate exists, and never let a register built for one quantity answer a question about a different one. “Basis of measurement” credits the Commission’s SWD(2025) 38 final for the register and Ricardo’s report for DG CLIMA on MRV extension to vessels below 5,000 GT, March 2025, Table 2-1, for the tier below it, notes that the study’s figures are AIS-based modelling rather than returns, that its eighteen rows sum to 8,526 against the 8,525 it prints and that its yacht count covers private as well as commercial operations, and says the averages, sums and per-vessel figures are ours. Five notes run along the foot: the same reporting year; the same published figures; one zero-based axis per pair; the excluded tier drawn, not omitted; estimates labelled as estimates. A closing footnote credits both sources and states that both drawings are ours, that the desk, the read-out and the recommendation on the first are invented, and that every figure behind them is real. — Showing the misleading chart

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A port decarbonisation briefing we drew puts the fleet calling at European ports on one zero-based axis, using the European Commission’s own published summary of the 2023 returns under the EU Maritime MRV Regulation: 12,344 ships, 126.7 million tonnes of CO₂, every return verified, the rule flag-neutral, reporting compulsory. Five ship types are 79% of the arrivals, the top three are 52% of the carbon, and small craft do not appear at all. Nothing is bent — but the Regulation collects only from ships above 5,000 gross tons, so the register is a census of what clears a line rather than of what calls at a port. A study the Commission’s own DG CLIMA commissioned counts 8,525 vessels of 400–4,999 GT calling at EU ports in the same year, 69.1% as many ships as the register holds, emitting an estimated 18.99 Mt: fishing boats, yachts, tugs, small ferries, small general cargo ships. Put them back and the headline goes with them — the five named types fall from 79% of the arrivals to 63.3%, and general cargo moves from fifth place to second.

European Commission, “2024 Report from the European Commission on CO₂ Emissions from Maritime Transport”, SWD(2025) 38 final, 12 February 2025 (reporting year 2023): 126.7 Mt CO₂, the ship-type shares and the coverage sentence. Vessels below the threshold, and the exact count of 12,344 reporting ships, from Ricardo for DG CLIMA, “Supporting study for the implementation of the ETS Directive and MRV requirements for maritime transport — Report on MRV extension to vessels below 5,000 GT”, March 2025, Tables 2-1 and 4-3: 8,525 vessels of 400–4,999 GT calling at EU ports in 2023 and 18.99 Mt CO₂, from AIS-based modelling. Per-vessel averages, sums and rebased shares ours. Retrieved 11 September 2026, 2025Added September 11, 2026

01The claim

This is the fleet that calls at European ports. The figures are the European Commission’s own published summary of the 2023 returns under the EU Maritime MRV Regulation, and they are as good as administrative data gets: reporting is mandatory, the rule is flag-neutral so a ship reports whatever flag it flies, every return is checked by an accredited verifier before publication, and the whole register is published ship by ship. 12,344 ships filed for 2023 and reported 126.7 million tonnes of CO₂ on voyages to, from and between ports of the European Economic Area. The axis is linear, zero-based and evenly ticked; the shares are the Commission’s own, at the precision it published them; nothing has been sampled, smoothed, indexed or rescaled. Five ship types are 79% of the arrivals — bulk carriers 29%, oil tankers 15%, container ships 15%, chemical tankers 11%, general cargo ships 9% — and on the carbon chart the top three types are 52% of reported emissions, container ships alone 28%. Read-out for the desk: bulk carriers, tankers and container ships are the fleet, no other named ship type on either chart reaches a tenth of it, and small craft do not register at all. Point the shore-power and berth-emission programme at the container terminals and the tanker and bulk berths; a small-craft programme has nothing on this evidence to aim at.

02The trick

Every number on that slide is right, the axis really is zero-based, no ship in scope is missing — and the chart is still not a picture of what calls at a European port. The words doing the work are “in scope”. The EU Maritime MRV Regulation collects from ships above 5,000 gross tons, so what the register holds is not the fleet but the part of the fleet that clears a line, and the line was not a measurement. It was a costing: the 2013 impact assessment put the paperwork at about EUR 5,545 per vessel per year if every ship above 400 GT reported, against EUR 4,479 if only ships above 5,000 GT did (those are the 2013 figures restated in 2023 prices), and smaller vessels were left out on grounds of administrative burden and proportionality. That is a reasonable decision about forms. It then quietly became the edge of the data. Below the line a study the Commission’s own DG CLIMA commissioned, modelling AIS traffic for 2023, counts 8,525 vessels of 400–4,999 GT calling at EU ports — 69.1% as many ships as the register holds — emitting an estimated 18.99 Mt of CO₂, or 15.0% of the reported total. Sorted by number they are general cargo 2,296, fishing 1,065, offshore 921, yachts 896, chemical tankers 756, RoPax ferries 571, tugs 385, and on down to twenty ro-ro vessels. Some of those categories have no row on the first slide at any length, and that is the part worth dwelling on: a small quantity arrives as a short bar, which the eye reads as small, but an excluded quantity arrives as no bar, which the eye reads as nothing. The damage is heaviest where the slide is loudest. Its headline is a claim about counts — twelve thousand ships, five types four fifths of them — and counts are exactly what a tonnage line takes apart: over both tiers the five named types are 63.3% rather than 79%, and general cargo climbs from fifth place to second, because 2,296 of the missing vessels are general cargo ships. On carbon the tier would be 15.0% against container ships’ 28%, bulk carriers’ 11% and oil tankers’ 13% or so — second among the named types, on a chart where it has no band at all. What makes the threshold so hard to see is that it works. It was set to capture emissions and it captures them: a vessel in the register emitted an average of 10,264 tonnes of CO₂ in 2023 against about 2,228 tonnes for one below the line, a fifth as much, so the register holds roughly 87% of the carbon counted here while holding 59% of the ships. The Commission says exactly this in its own front matter — the Regulation “covers around 90% of all CO₂ emissions in the EU maritime transport sector, whilst only including around 55% of all ships calling into EEA ports” — one sentence, two numbers, and they are not the same number. A register built to weigh carbon is superb evidence about carbon and poor evidence about how many ships there are, and nothing on the chart says which question it is answering. Two more edges are worth knowing, and the study’s own scenario arithmetic separates them cleanly. Only 2,460 of the missing vessels, carrying 6.19 Mt, are held out by tonnage alone; another 2,849, carrying 5.13 Mt, are out of scope by type or activity at any size — fish-catching and fish-processing ships are excluded by name, and tugs, service craft and private yachts carry neither cargo nor passengers commercially, so no tonnage would bring them in. And the line moves: from 2025 small general cargo and offshore ships report too, which brings the remaining 3,217 vessels and 7.67 Mt across with nothing in the world having changed. (The Commission and its consultants publish these figures as tables and prose; both drawings are ours, and the desk, the read-out and the recommendation on the first are invented.)

03The fix

Draw the line, then draw what is under it. The redraw keeps every published figure and adds three things the first slide had no room for: both tiers on one zero-based axis, so 12,344 ships and 8,525 sit against the same ruler; the eighteen below-the-line categories as their own sorted bars, with each one’s estimated carbon printed beside it; and both of the briefing’s charts recomputed over everything counted on the page, 20,869 vessels and 145.69 Mt, where the five named types drop from 79% of the arrivals to 63.3%, general cargo rises from fifth to second, and the missing tier takes a 13.0% band of the carbon. The colouring does the rest of the teaching, and it follows the study’s own scenarios: gold for the 2,460 vessels held out by tonnage alone, which a higher line would bring in; orange-red for the 2,849 that are out of scope by type or activity at any size; blue for the 3,217 already due to join in 2025. In general: put the eligibility rule in the caption the way you print a unit — “ships above 5,000 gross tons”, “facilities above 25,000 tonnes”, “firms with ten or more employees” — because a register without one is a chart whose population is a secret. Where somebody has estimated the excluded tier, and for most large registers somebody has, since the regulator needed a number before it set the line, give that estimate a bar in its own shade and say it is modelled: a labelled estimate is read as an estimate, while white space is read as a zero. Where no estimate exists, write the sentence anyway. Annotate the year the scope changed rather than letting the series step. And match the register to the question: these returns are an excellent measure of maritime carbon and a poor census of ships, and the only thing standing between those two readings is a line in Article 2 that the picture never mentions.