The International Maritime Organization has published the findings of a study into shipping’s global emissions that are set to have a radical impact on efforts to reduce the industry’s carbon footprint.

The global shipping regulator's Fourth Greenhouse Gas Study has revealed that despite improvements in engine and hull efficiency, and slower average speeds, shipping’s carbon emissions are increasing.

Overall, shipping’s carbon emissions rose from 962m tonnes to 1.06bn tonnes between 2012 and 2018, the study led by consultancy CE Delft found.

The increase comes despite an 11% improvement in carbon intensity, which is a ship efficiency measure of emissions in relation to cargo carried. Shipping’s share of global emissions also increased from 2.76% to 2.89%.

Ship efficiency gains are having little impact on total emissions, which will now increase pressure on the IMO to raise its 2030 target of achieving a 40% improvement in carbon intensity, compared with 2008 levels.

The IMO is not commenting on the report. But a revision of the 40% target is now likely to be discussed at the next Marine Environment Protection Committee meeting, which is set to be held online this autumn.

Raising the target

One delegate said the IMO will likely be pushed towards an 80% improvement in carbon intensity, if it is to achieve a reduction in emissions in line with the Paris Agreement on climate change.

The findings will also raise questions as to whether proposals from Japan for an energy efficiency index rating for existing ships, or from Denmark for a carbon intensity index, will be adequate given shipping’s worsening emissions profile. Both proposals are framed around a 40% target. More radical proposals, such as a speed limit for ships, could return to the negotiating table.

In response to the report, Faig Abbasov, shipping programme manager at lobby group Transport & Environment, urged regional action in Europe.

“Shipping's carbon pollution has grown at an alarming rate and could rise by half by 2050 if real action is not taken. Now is the time for the European Union to push ahead with its plan for emissions trading for shipping and also quickly adopt CO2 standards for the European Parliament,” he said.

The report also revealed that about 30% of shipping's emissions involve coastal trades that are the responsibility of national governments, rather than 15% as previously estimated. This will raise the question of whether national governments should be doing more to regulate emissions rather than rely on the IMO.

It will also raise the prospect of a more fragmented regulation of shipping emissions rather than the global rules.

Dr Elena Hauerhof of the University Maritime Advisory Services said: “More attention should be paid to shipping in national greenhouse gas policy.”

Shipping emissions expert Tristan Smith, of the UCL Energy Institute, said the report should encourage national governments to be more proactive in providing a low-emission fuel supply on the shore side to help international shipping improve its emission performance.

Role of LNG

The other issue the study raises is the role of LNG as a marine fuel in its carbon reduction project.

The UCL's Tristan Smith believes the report should encourage national governments to get more involved in improving shipping's emissions performance. Photo: June Essex/LISW

The study found a 150% increase in methane emissions from shipping over the 2012 to 2018 period was largely attributable to the 28% increase in ships burning LNG.

The report found that LNG-fuelled engines are geared towards dramatically reducing NOx emissions, but not methane.

There are now proposals for the regulation of methane emissions in the IMO's energy efficiency design index for newbuildings.

Dr Bryan Comer, senior researcher with the International Council on Clean Transportation, said: “If [the] IMO wants to meet its climate goals, it must take swift action to prevent excess methane emissions from LNG-fuelled ships.

"We expect the IMO to include all greenhouse gases, including methane, in the next phase of the EEDI [Energy Efficiency Design Index].”