Turning the ship, slowly: Progress at IMO on new ship efficiency and black carbon

At the 74th session of its Marine Environment Protection Committee (MEPC 74) last week, the International Maritime Organization (IMO)—the United Nations specialized agency that regulates international shipping—strengthened energy efficiency standards for new ships and instructed its Pollution Prevention and Response (PPR) subcommittee to consider concrete proposals for cutting black carbon emissions from international shipping when it meets again in early 2020. Like the hulking oceangoing vessels it regulates, the IMO can take time to steer in the right direction, and this was important, if not particularly impressive, progress.

Specifically, and as the table below details, the IMO moved up the start date of Phase 3 of its Energy Efficiency Design Index (EEDI) standards for new ships by three years, from 2025 to 2022, for five ship types: container ships; general cargo ships; liquefied natural gas (LNG) carriers; other gas carriers; and cruise ships. The IMO also changed the container ship targets, which were a 30% carbon-intensity reduction (i.e., improvement) from baseline in 2025, to a sliding scale. This cuts small container ships some slack, but makes the largest ships responsible for achieving a 50% reduction.

Ship types with Phase 3 EEDI targets moved up to 2022

Ship type Size (deadweight tonnes) Carbon intensity reduction from baseline Share of 2015 CO2 from ships covered by EEDI
Container ships 10,000 to 14,999 15% to 30%1 24%
15,000 to 39,999 30%
40,000 to 79,999 35%
80,000 to 119,999 40%
120,000 to 199,999 45%
200,000+ 50%
General cargo 3,000 to 14,999 0 to 30%1 5%
15,000+ 30%
LNG carriers 10,000+ 30% 3%
Gas carriers 15,000+ 30% 3%
Cruise ships2 25,000 to 84,999 0 to 30%1 3%
85,000+ 30%
Total 38%

1 Calculated by linear interpolation, based on vessel size.
2 Those with “non-conventional” (i.e., diesel-electric) propulsion, which is what powers nearly all new cruise ships. Note that “size” for cruise ships is measured in gross tonnes.

Of ships subject to EEDI regulations, the five ship types affected by this decision were responsible for about 30% of ships (by number) and about 40% of carbon dioxide (CO2) in 2015. According to our models, this strengthening of EEDI Phase 3 will avoid approximately 750 million tonnes (Mt) of cumulative CO2 emissions between 2022 and 2050, and this is roughly equivalent to total CO2 emissions from international shipping in 2010.

The EEDI standards have been criticized for being too weak to encourage innovation because shipowners can comply by building larger ships or building ships with smaller engines than the older ships reflected in the EEDI baseline. These stronger Phase 3 standards still probably won’t fundamentally change how ships are built, but because shipbuilders haven’t yet achieved Phase 3 targets with conventional designs of certain ship types, they set the stage for Phase 4 standards that could require shipowners to invest in innovative technologies such as wind-assist or hull air lubrication, or to use batteries or fuel cells to replace at least some of their energy use. In our new case study analysis, we found route-level carbon intensity could be reduced by 1% to 47% with rotor sails (1% to 12% per rotor) and 3% to 13% with hull air lubrication.

Beyond that, the EEDI could be used to promote zero emission vessels (ZEVs) operating on fuels like hydrogen and electricity. As we showed in this paper, accelerating the pace of technical efficiency improvements for new ships through the EEDI is a necessary, but not sufficient, part of achieving the IMO’s intial greenhouse gas (GHG) strategy, including its long-term emissions reduction target of at least halving GHG emissions from the sector by 2050 compared to 2008 levels. At MEPC 74, the IMO established a correspondence group, led by Japan, to discuss possible Phase 4 targets between now and MEPC 75 (spring 2020). We expect the IMO to develop these standards, but we do not yet know when they would come into effect. Originally, there were five-year increments between EEDI phases, but now there’s only a two-year increment between Phase 2 and Phase 3 for the ship types in the Table. It remains to be seen how ambitious IMO member states will be going forward.

Regarding black carbon, MEPC 74 instructed PPR 7, which will meet in early 2020, to consider concrete proposals on how to cut black carbon emissions from international shipping. Under the agreed schedule, the IMO will make a black carbon policy decision at MEPC 77 in fall 2021. Our research shows that black carbon accounts for 21% of the CO2-equivalent emissions from the global shipping sector on a 20-year timescale, making it the second-largest contributor to shipping’s climate warming impact after CO2. Participants in ICCT’s 5th workshop on marine black carbon emissions identified 13 technologies, including using cleaner fuels that emit less black carbon, exhaust gas aftertreatment technologies such as diesel particulate filters or electrostatic precipitators, and zero emission technologies such as batteries and fuel cells, that could control black carbon. Moreover, we’re convening a 6th workshop in September 2019 in Finland, with the goal of identifying black carbon control policies for delegates to consider at PPR 7.

While stopping short of concrete decisions, the MEPC 74 meeting also discussed other areas where ICCT researchers are active. Among these were actions to reduce emissions from the existing fleet before 2023, the potential dangers of open-loop scrubber discharges, progress towards establishing a Mediterranean Sea Emission Control Area, the importance of controlling releases of unburned methane (aka methane slip) from marine engines that operate on LNG, and the need for research and development to accelerate deployment of ZEVs and their fuels. Watch this space for future updates. We will be hosting a two-day technical workshop in July in San Francisco on propulsion technologies and fuels to support zero emission shipping. Maturing those technologies, and then developing policies to accelerate their uptake, is key to meeting the IMO’s goal of reducing GHGs from shipping by at least 50% in 2050 and delivering on other ambitions laid out in the initial GHG strategy.

Overall, the IMO made decent progress on important environmental issues at MEPC 74. Steering it in the right direction takes time, and while it’s not full steam ahead towards IMO’s vision of complete decarbonization yet, last week’s decisions will reduce emissions and set the stage for larger reductions.