Port emissions data specialist PortXchange on Tuesday (22 September) said nine months after the Netherlands became the first country to impose a binding decarbonisation obligation on marine fuel suppliers rather than on the ships they serve, Spain has followed with Royal Decree 611/2026. The company said the market data from Rotterdam shows what other ports should expect if the mechanism keeps spreading unevenly. Since Dutch rules took effect on 1 January 2026, requiring fuel suppliers to cut the greenhouse gas intensity of bunker fuel sold in the Netherlands, Rotterdam’s bunker sales have fallen sharply, dropping 648,399 tonnes in the first quarter of the year to their lowest level since 2009. Belgium has delayed introducing an equivalent rule and Germany has so far excluded maritime fuel from its own transposition, so the volume that left Rotterdam has moved to ports with no equivalent obligation rather than being decarbonised. By September, Rotterdam’s compliance-driven price premium over its nearest competitor had widened to USD 20-25 per tonne. Spain’s Royal Decree 611/2026 applies the same principle, a binding obligation on fuel suppliers rather than vessel operators, but scopes it to domestic cabotage shipping, with a greenhouse gas intensity reduction curve rising from 6.5% in 2027 to 33% in 2040. Spanish ports will also be required to report annually on the fuel and electricity they supply, categorised by type. The timing is pointed. The IMO’s own attempt at a single global mechanism, the Net-Zero Framework approved in principle in April 2025, failed to secure adoption at an extraordinary session in October 2025 on a 57-49 vote. The question returns to the table this winter: an intersessional working group meets on 23-27 November 2026, immediately followed by MEPC 85 and the resumed extraordinary session from 30 November to 4 December, where the adoption vote is expected to be revisited. PortXchange argues the EU’s national rol