A French-led delegation to the IMO has this year called for mandatory slow-steaming as the most effective method to lower emissions, and at the G7 summit in Biarritz in August, President Macron reaffirmed France's commitment to slow-steaming.
However, shipowner associations have been critical of slow-steaming lobbyists, claiming a mandatory speed reduction in shipping could have 'unwanted consequences,' reported London's Loadstar.
Policy director of the UK Chamber of Shipping Anna Ziou said speed limits as the tool for cutting vessels emissions would give a 'false impression' of the industry acting.
'To achieve a 50 per cent cut in emissions, the shipping industry needs continued investment in green technologies,' she argued, such as battery power and hydrogen fuel cells for low carbon propulsion.
According to Maritime Strategies International's senior analyst Dan Richards, container shipping lines faced a 'trade-off' between minimising fuel bills, thus cutting emissions, but no longer being able to offer a full network of port pairs.
'Put another way, a liner company could reduce its fuel bill only to find its market share eroded by a different carrier offering more varied and faster transits,' he wrote in a post published by London's Loadstar.
In a discussion document, shipping association Bimco agrees that a ship's speed is the 'single most important variable influencing its CO2 emissions' and that short-term measures reflecting this should be 'pursued as a priority.'
Nevertheless, it says the capping of a ship's speed is 'not easily assessed,' and that environmental conditions such as sea currents, sea state and weather 'impact heavily on the relation between speed over ground and speed through water'.
Instead, aiming a regulatory measure at the wide range of options related to a ship's efficiency 'would be desirable'.
'Measuring a ship's speed is not an accurate exercise, therefore other avenues have been investigated. It has been concluded that limiting ships' propulsion power can be controlled accurately and, at the same time, it has a close correlation to speed,' said Bimco.