Ship speeds on Red Sea rerouting to 'erode' GHG cuts

Ships increasing speed as they are forced to sail longer routes to avoid Houthi attacks in the Red Sea could "erode" environmental gains in shipping, the United Nations Conference on Trade and Development (UNCTAD) said today.

The shipping sector has for over a decade reduced sailing speeds to cut fuel costs and reduce greenhouse gas (GHG) emissions, UNCTAD said. Speed optimisation is one of the solutions shipowners can consider to improve their rating under the International Maritime Organisation's (IMO) carbon intensity indicator (CII) measures which came into force in January 2023.

Container ships' speeds for voyages around the Cape of Good Hope at the southern tip of Africa have increased since the Red Sea disruption started late last year. Container trade flows measured in tonnes account for over half of traffic through the Suez Canal, according to the Suez Canal Authority.

Higher speeds are likely being used as a way of adhering to delivery schedules but also to manage fleet capacity, as longer routes mean vessels are employed for a longer period of time. UNCTAD said that these trends could erode environmental gains previously achieved by ships reducing speeds, or slow steaming.

The organisation calculated that a ship increasing speed to 16 knots from 14 knots would increase bunker fuel consumption per mile by 31pc. "In this context, longer distances travelled due to rerouting away from the Suez [Canal] and through the Cape of Good Hope imply that greenhouse gas emissions for a round trip from Singapore to northern Europe would rise by over 70pc," it said.

Ship tonnage entering the Gulf of Aden declined by over 70pc between the first half of December 2023 and the first half of February 2024, while ships passing the Cape of Good Hope increased by 60pc, UNCTAD noted.

The security issues in the Red Sea have also affected insurance costs for shipowners, UNCTAD said. "By early February 2024, some reports indicate [risk] premiums rising to around 0.7pc to 1pc of a vessel's value, from under 0.1pc previously," UNCTAD said, citing a report by ratings agency Moody's.

Ships avoiding the Suez Canal, particularly container vessels, also pose a risk to "global supply chains, potentially leading to delayed deliveries, heightened costs and inflation", it said. "The war in Ukraine had already shown the impact of longer distances and freight rates on food prices."

UNCTAD estimates that about half of the increase in food prices observed in 2022 resulted from increased transport costs caused by longer distances and higher freight rates.

By Caroline Varin