France’s delegation to the International Maritime Organisation in London has proposed mandatory slow steaming as a means of cutting the shipping industry’s greenhouse gas emissions
France is suggesting that speed limits differentiated by shipping sector should be implemented "as soon as possible," according to a proposal document for the IMO’s GHG emissions working group seen by S&P Global Platts. Reducing a ship’s speed to the level at which it has maximum fuel efficiency reduces its bunker fuel consumption and emissions.
The IMO’s initial strategy on GHG emissions seeks to cut the shipping industry’s total GHG emissions by at least 50% from 2008 levels by 2050, and to reduce carbon dioxide emissions "per transport work" by at least 40% by 2030. The strategy, which is independent of the 2020 sulphur cap, is due to be revised by 2023.
Mandatory slow steaming could help reduce GHG emissions as a short-term measure while new technology is being developed. It could significantly reduce global bunker demand, but not if more new vessels are built to fill the supply gap that slow steaming creates.
In 2017, two NGOs, Seas At Risk and Transport & Environment, presented a report to the IMO they commissioned from CE Delft showing that cumulative savings from slow steaming of containerships, bulkers and tankers could cut shipping’s global footprint by 12% by 2030.