As we have been discussing, the US National Blueprint for Transportation Decarbonization breaks the Transportation sector into seven categories, each of which has its own targets for emission reduction/elimination, and strategies for how those declines in emissions will be achieved. The next category addressed in the Blueprint by emissions % is the Maritime Sector.
The Maritime sector includes domestic, international, and recreational vessels under its umbrella. All in, there are an estimated 12 million privately owned recreational vessels, and 38 thousand commercial vessels including ferries, tugboats, container ships, etc.
About 20% of emissions in the sector come from recreational vessels, which primarily use gasoline. Domestic shipping and International shipping both contribute around 30% of the emissions share each. This segment primarily runs on diesel, with some percentage coming from heavier residual oils in large international vessels.
An important factor in emissions calculation for the Maritime sector, as well as for how effective efforts to curb them will be is the fact that its very difficult to get exact numbers on emissions given the complicated nature of international vessel traffic and fueling. Additionally, international vessels (including those flagged under the US) fuel up across the globe, often in areas that may not have the same options for less carbon intensive fuels.
The maritime sector, given its multinational presence, will require huge amounts of cooperation and agreement across nations in order to address the sector as a whole. Coordination amongst port owners, vessel operators and local and international governments will be pivotal to success. Part of this process thus far is the DOE “Mission Innovation Zero-Emission Shipping Mission” which aims to ensure that at least 10 ports on 3 continents can supply zero-emission fuel by 2030, and that 5%+ of the global fleet runs on those zero-emission fuels.
Ports are a huge factor in decarbonizing the sector, and international cooperation will be critical to movement forward.
The global nature of the maritime sector is a huge segment needing to be addressed as relates to Environmental Justice concerns, as well. Port communities in some areas are now and have historically been made up of disadvantaged groups that disproportionately bear the brunt of poor air quality and pollution sometimes caused by the industry. Resolving the emissions and pollution issues around port cities globally will need to be part of the long-term strategy on climate.
A major hurdle in addition to the global nature of vessel transport, is the long lifecycle of maritime equipment. When we think of upgrades in technology and emissions regulation adoption, we typically picture cars and trucks – both of whom have a much much shorter lifecycle than maritime vessels. The usual turnover time for large marine vessels is upwards of 30 years, and the cost associated with new vessels can be staggering. All of which is to say that advances likely won’t have substantial impacts in the near term unless they work with existing fuel types and refuel patterns.
Areas of focus include sustainable liquid/gas fuels that are drop-in replacements for the existing fossil fuels being used. This option is likely the most viable interim option, given the long lifetime cycle of the vessels and the existing port infrastructure that keeps them fueled and moving. On smaller boats, there are options for electrification that may or may not prove viable over time but again, where recreational/small vessels are not the major offenders, the offset by this solution seem minimal.
Two interesting and seemingly easily adoptable options for overall reduction in emissions appear to be the following
- Cold Ironing – this is essentially “plugging in” or running large vessels off electricity during their time in port to offset emissions, particularly those that harm the immediate port city environment.
- Exhaust Treatment and Carbon Capture – there is an idea that post exhaust emissions from vessels could be treated and neutralized (sort of like a reverse DEF process) to mitigate the ultimate CO2 impact. Logistically there seems to be some issues with how exactly the process would work, and what the options for storage and disposal would be in a marine environment.
Much like the other sectors we have discussed, investment in infrastructure will be a huge critical piece of the puzzle. Part of the underlying requirements for success of new regulations is that people are able to access the things that make complying with them possible, whether that is a fuel type or charging station, etc. In the Maritime sector this is more complicated, as discussed. There are however, options being made available through the Inflation Reduction Act (funding for ports to purchase zero-emission equipment, resources for climate planning), and the Port Infrastructure Development Program (grants for terminal infrastructure improvements).