Slow-steaming hardly an emissions silver bullet

Slow-steaming hardly an emissions silver bullet

The International Maritime Organization

Things are beginning to get interesting — if not serious — on climate change as it pertains to container shipping, the most recent example being an international campaign to impose speed limits on ships.

We already know that the next decade will be a hyperactive period of innovation as the industry confronts the challenge of producing a carbon-neutral ship by as early as 2030; that is the year when Maersk says it must deploy the first such vessel to be on track to fully decarbonize what is today a fleet of 640 ships by 2050.

But the greenhouse gas (GHG) strategy adopted by the International Maritime Organization (IMO) last April, in addition to committing the industry to a 50 percent reduction of carbon dioxide levels by 2050 compared with 2008, calls for “early” measures needed to achieve reduction of GHG emissions from international shipping before 2023, when shipping climate change goals will next be revisited.

That rapidly approaching deadline, three-and-a-half years away, has given way to the belief that only operational steps can take a meaningful bite out of emissions because no one currently knows which zero- or low-carbon propulsion sources will be technologically and economically viable.

And to some, the biggest opportunity out there is one that’s simple, straightforward, and impactful: slow down ships by mandating speed limits on the high seas. It’s a solution that has worked before. Citing a 2014 IMO study, emissions from international shipping dropped 13 percent between 2008 and 2012, thanks largely to voluntary slow-steaming in the wake of the 2008 global economic crisis, according to the Brussels-based research group Transport & Environment.

Shipping accounts for approximately 2.5 percent of global GHG emissions, and liner shipping accounts for a quarter of that, according to the World Shipping Council.

That is why with the approach of the 2023 date, slow-steaming is seen by some as enticing. France in April proposed to the IMO that mandatory slow-steaming be implemented “as soon as possible,” specifying that a new rule should include container ships.

A group of 110 mostly bulk shipping companies, including a number of non-vessel-operating common carriers — but conspicuously lacking any container carriers — signed an April 30 letter calling for mandatory slow-steaming to be adopted at the upcoming May 13-17 meeting of the IMO GHG working group.

“Our preference would be to set maximum annual average speeds for container ships,” the letter said, noting that “recent studies also suggest that ships are speeding up again as global demand recovers.”  

Although IMO action on slow-steaming is considered a long shot, on one level, the focus on the issue is an example of how addressing climate change is beginning to move from speeches, articles, and policy statements to potentially having a real world impact. According to the letter, “deep emissions reductions” globally will be required to limit temperature increases to well below 2 degrees Celsius as agreed in the landmark 2015 Paris climate accord, a goal that is already seen as being in peril.

But on another level, it shows how the pursuit of solutions with cosmetic appeal could have deep economic ramifications and possibly undermine efforts to achieve stated goals for carbon dioxide reduction.

Limiting vessel speeds of container ships is a good example. Container ship services operate mostly on weekly schedules, supporting global supply chains in food, consumer, and industrial products that require predictable transport services, even if those services are frequently delayed. Mandating slow-steaming would require additional ships to maintain weekly schedules, which would add more carbon to the air, not to mention potentially denying operators the flexibility needed to avoid situations such as dangerous weather.

According to Hapag-Lloyd spokesperson Nils Haupt, “If we reduce speed in a loop from Hamburg to Singapore which requires 12 ships, to stay on schedule and maintain a regular weekly service, you would need a 13th or 14th ship, which means investment and additional CO2 [carbon dioxide] pollution. This is something that bulk carriers and tankers don’t have to take into account, but for containers it would be harsh investment and wouldn’t really solve the program,” he said.

As Jonathan Gold, vice president of supply chain and customs policy for the National Retail Federation, said bluntly via Twitter, “This is the wrong approach and should not be supported.”

Further slow-steaming, on top of what carriers implemented during the financial crisis and never fully reversed, may be coming irrespective of whether the IMO takes action in response to the petitions at the upcoming 74th Marine Environmental Protection Committee meeting (MEPC 74).

A new round of self-imposed slow-steaming by the maritime industry overall may result from sulfur emissions limits to be imposed by the IMO on Jan. 1, 2020. Estimates for the cost of compliance for container carriers is between $10 billion and $15 billion in annual fuel expenses. Maersk has said it expects its fuel costs to increase $2 billion a year as a result of the rule, while Hapag-Lloyd has projected a $1 billion per year cost increase.

Historically, when fuel prices increase, ship speeds slow down. The bottom line: it's the debate on slow-steaming, not ship speeds, that needs to slow down.

Contact Peter Tirschwell at and follow him on Twitter: @petertirschwell.