Mandatory Ship Speed Reduction Could Reduce Bunker Consumption and Cut GHG Emissions by One Third: Study

A new study says a 10% speed reduction would still see a slight increase of emissions between 2018 and 2030, while the other two scenarios would put shipping emissions on a downward path even in the absence of other measures. Image Courtesy: T&E

A new study conducted by CE Delft for NGOs Seas At Risk and Transport & Environment (T&E) suggests that by reducing bunker consumption through the implementation a mandatory speed reduction for vessels, greenhouse gas (GHG) emissions from container ships, bulkers, and tankers could be reduced by a third.

"In the period up to 2030, baseline CO2 emissions could be reduced by 13, 24 and 33% if the ships reduced their speed by 10, 20 and 30%. A 10% speed reduction would still see a slight increase of emissions between 2018 and 2030, while the other two scenarios would put shipping emissions on a downward path even in the absence of other measures," the study says.

"Regulating speed: a short-term measure to reduce maritime GHG emissions" will be presented to the International Maritime Organisation (IMO) next week as part of the latest talks on addressing shipping's CO2 emissions.

By 2030, savings could amount to a total of 12 percent of shipping's remaining carbon budget under a 1.5ºC climate goal by reducing the speed of such ships, says the study.

Further, the study finds that the increased costs from slow steaming on exports such as oilcake and beef from Latin America would be marginal, even without accounting for lower transport fuel costs.

While slow steaming would result in increased voyage expenses due to additional sailing days, T&E says that the reduced fuel costs mean "net additional expenses could be zero or negative for shipowners."

Slow steaming has become common practice in recent years as despite the longer voyage times, it reduces overall bunker costs.

"[The] industry itself showed clearly that slow steaming works. It proved effective in weathering the economic crisis, so the IMO should now agree mandatory speed measures to achieve substantial emissions reductions needed to start decarbonisation," said Bill Hemmings of T&E.

While the ship types analysed in the study are said to account for about 52 percent of global shipping's carbon footprint, it is suggested that "substantial additional savings" could be made through the reduction of speed in the remainder of the fleet.

"A new regulation to reduce ship speed will be key to the success of the IMO GHG strategy. Only reduced speed can give the fast, deep short-term emissions reductions that are needed for shipping to meet its Paris Agreement obligations," said John Maggs, Senior Policy Advisor at Seas At Risk.

"Significant early emissions savings are essential for the long-term decarbonisation of the sector as they preserve shipping's carbon budget and buy the industry time to develop longer-term decarbonisation solutions. Recent suggestions by industry that no new short-term measures are needed is misguided and reckless, and threatens to undermine the IMO strategy right from the start."