IMO Greenhouse Gas ambitions – Do we really know what we are in for?

At MEPC 72 history was made in as much at the organization agreed specific targets for the maritime clusters GHG emissions. This achievement was generally – and rightfully – hailed widely as a major achievement.


The question that now needs to be answered is what does it actually entail? I am especially interested in one of the ambitions that appeared in the enddocument[1]:


.2 Carbon intensity of international shipping to decline

"To reduce CO2 emissions per transport work, as an average across international shipping, by at least 40% by 2030, pursuing efforts towards 70% by 2050, compared to 2008, and…."


These few lines actually raise a number of issues before we can really start to understand and measure our emissions.


Firstly, it is specifically mentions CO2 as opposed to GHG. That nicely excludes methane from the discussion. The next thing that tricked my brain waves was the reference to “transport work”. Something the IMO has stayed away from, and a topic that gave fuel to much debate during the discussions at MEPC leading up to the IMO Fuel Oil Data Collection System (DCS). DCS will have its first reporting year in 2019. What MEPC could agree for DCS was to use DWT as a proxy for transport work and therefore this figure will govern future reporting under this system. This is one of the key differences to the EU MRV Regulation where “transport work” is actually defined as what the ships carry of cargo and passengers.

Considering the discussions during the DCS debate at MEPC, it is unlikely that members will agree a different, more accurate definition for transport work when it comes to reporting and calculating on the 40% reduction target set for 2030. So, if the DCS is the data going forward, our baseline has to be structured around the identical elements, in order for us to compare and note the progress.

In this context it is also important to remember the base line timing. This is given as “2008”, but what data do we actually hold for 2008 that can give use a useful baseline for this KPI? This is where the key problem occurs. Do we establish the correct base line or do we establish the possible base line? The answer is self-evident. We can only establish the possible baseline and disregard whether this actually represents the values we are looking for.


The 2008 base data will no doubt originate from the IMO 3rd GHG study. Noting that this study actually reports two different figures for CO2 emissions in 2008 may be the smallest of the problems. After all, whether to take the “top- down” or the “bottom- up” figure will be a onetime argument. Since the DCS is a bottom-up exercise, that discussion should be relative short-lived.

That really leaves the “transport work” as the unknown factor. We will have the World fleet anno 2008 in a database somewhere. The IHS Markit being the likely, and preferred IMO source. Despite its issues with data quality, it may give us a fair estimation of the World fleet in 2008. This assumes the historic database has been kept or can be recreated, taking in to account any ship modifications of relevance. So establishing the global fleet anon 2008 should not be too difficult.

The 2008 distances can be extracted from the historic AIS database, so that really only leaves one serious unknown – the cargo carried.


The IMO 3GHG study does not provide its own data from cargo flows but refers to UNCTAD data. This source does not fully cover the scope of international shipping. That really only leaves us with the DWT figure as the proxy value for cargo.

If you can’t get what you love, you must love what you can get.


Let’s take a closer at this acronym – DWT.

To find a ships official DWT, you need a bit of a detour as there is no official “DWT certificate”. DWT is defined as the vessels displacement less its light weight. Both of these can be found on a certificate, the only real problem is that it is not a constant value. Ships change over time and therefore both displacement and lightweight figures may change. This calculation in itself is not a tricky exercise, as long as you operate with the correct certificates at any given time. There is just a bit of bureaucracy involved when calculating the annual DWT x nautical miles.


The fundamental problem being, that regardless of whether a ship has any cargo onboard or not, the DWT remains the same. As a ship in ballast normally burns less fuel that a laden one, the data will show that empty ships are more efficient than laden ones – according to this KPI.

Another victim of measuring what is possible compared to what is correct, is the CO2 emission. We find it a relative easy task to calculate or measure a vessels consumption of fuel and applying a CO2 emission factor to this figure. That will give us a tank-to-propeller CO2 value. Our planet’s atmosphere does frankly not care from which section of the chain the C02 emits. Our inability to judge the upstream CO2 emission -not least historically - puts us in the situation where we conveniently will have to disregard this portion of the equation.


Being measured on one’s tank-to-propeller CO2 emission, eliminates biofuels as a source of energy. It also puts LNG in a more favorable position that it rightfully deserves.


Does this complete the picture? Unfortunately not.

If the IMO ambition has to pan out in to actual actions, responsibilities need to be apportioned somehow. Should this be on a flag basis, on location of the vessel operator on an individual owner/operator basis. The historic way of doing this would be on a flag state basis. One can then debate whether this is a fair way of allocating, but again the rule what is possible will prevail over what is desirable. Unless ownership of reaching this KPI is clearly allocated, I fear that it will remain nice words with no action.


So was the agreement reached at MEPC a failure?

No, on the contrary. It was an important step in the right direction. My reflections above is just an attempt to illustrate to us in the industry, we need to pick up the baton and ensure it is carried in the right direction from hereon. This will not be an easy task.


[1] MEPC 72/WP.7 Annex 1, page 5

Poul Woodall,

Advisory Board Member, Environment & Sustainability, SeaFocus Executive Maritime Business Platform



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