Cutting carbon emissions by regulating ship speeds should be considered by the industry as a short-term strategy to achieve ambitious Paris climate agreement goals, two environmental groups contend.

A study commissioned by environmental groups Seas at Risk and Transport & Environment (T&E) concluded that by bringing idle and laid-up ships back into the fleet, the additional capacity could be absorbed by reducing ship speeds by up to 3%, 8%, and 22% for dry bulkers, container ships, and crude and product tankers respectively.

Because less fuel would be burnt at the slower speeds, an immediate 4% cut in carbon emissions would be achieved, according to the study.

The two groups, which are founders of the Clean Shipping Coalition (CSC), plan to submit the study to the International Maritime Organization (IMO) when an IMO working group meets on 23–27 October in London to further develop its 2018 greenhouse gas (GHG) reduction strategy.

A submission to be considered by the working group, filed jointly on 7 September by the International Chamber of Shipping, BIMCO, Intercargo, and Intertanko, does not address the potential for regulating ship speeds, but contends that “aspirational objectives” towards a GHG reduction strategy “should have a non-binding character”.

John Maggs, senior policy adviser at Seas at Risk, countered that suggestions by the shipping industry that no new short-term GHG reduction measures were needed were “misguided and reckless”, and asserted that “only reduced speed can give the fast, deep short-term emissions reductions that are needed for shipping to meet its Paris Agreement obligations”.

The practice of reducing vessel speeds, known as slow-steaming, is typically used to lower operating costs when shipping is struggling, fuel prices rise, or both. It has also helped the industry cut its carbon output.

IMO studies have shown that total GHG emissions from international shipping decreased 10% between 2007 and 2012 – due in part to more efficient vessels, but also has a result of slow steaming. However, the recent recovery of the dry bulk and container freight markets from record lows last year has resulted in many of those carriers abandoning slow steaming in favour of higher speeds.

“The industry itself showed clearly that slow steaming works,” said Bill Hemmings, T&E’s director of aviation and shipping. “It proved effective in weathering the economic crisis, so the IMO should now agree mandatory speed measures to achieve substantial emissions reductions,” he said.

The study, conducted by environmental consultant CE Delft, pointed out that flag states and ports states both had the ability to monitor compliance with a speed regulation. “In some cases, they may have to build up the organisational capacity to do so,” the study asserted. “For example, it is not known how many flag states regularly monitor the position of their ships via either [Long Range Identification Tracking] or AIS, and it is not likely that any flag state currently monitors speed.”

The study also noted that it had yet to be determined whether it was more effective to regulate average or maximum speeds. “Probably regulating maximum speeds is easier to implement, because it doesn’t require regulation on how averages would be calculated,” it stated.

The World Shipping Council (WSC), which lobbies on behalf of container ship operators in Washington DC, has testified as to the environmental benefits of slow steaming and has weighed in on strategies to reduce GHG.

However, WSC president and CEO John Butler declined to comment on the general strategy of regulating vessel speeds as means of reducing carbon emissions without a specific proposal on the table.

“The idea has been floated before, but I’ve not yet seen a proposal that has received serious consideration,” Butler told Fairplay. “We’re looking forward to seeing the details of this and what a lot of others will be bringing to the IMO.”