Greenhouse gas (GHG) emissions from shipping have increased by 9.6 per cent from 2012 to 2018, marking a growth from 977 million tonnes to 1.1 billion tonnes. Emissions continue to rise and experts predict a 50 per cent rise in emissions by 2050.
These figures are according to the latest IMO study that has been prepared by a consortium of organisations and led by CE Delft.
While the report indicates that the carbon intensity of shipping has improved by about 11 per cent in the same period, the growth in activity was larger than the efficiency gains, leading to the higher emissions. The further growth in transport is likely to see emissions only worsen.
One of the biggest finds was the increase in short-lived climate pollutants. Methane has increased by 150 per cent between 2012 and 2018, while black carbon has risen by 12 per cent over the same time period. Methane traps 86 times more heat in the atmosphere than the same amount of CO2 over a 20-year time period.
According to the study, the rise in methane emissions has been largely fuelled by the operation of ships powered by liquefied natural gas (LNG) and the shift away from steam turbines to dual-fuel internal combustion engines. Methane slip occurs when unburned methane is released into the atmosphere and is one cause of the increase in the presence of methane. The study states that this rapid growth in methane emissions was foreseen in the Third IMO GHG Study scenarios. The study highlights the need to include methane in future phases of the IMO’s Energy Efficiency Design Index (EEDI) regulations. Currently, only CO2 emissions are limited under the EEDI.
Dr. Bryan Comer, a senior marine researcher who led the review and revision of the study’s bottom-up methodology, indicated that lack of methane regulation by the IMO is a problem.
“Methane is not yet regulated by the IMO, but it should be because it has a much stronger global warming potential than CO2. We urge IMO to include all greenhouse gases, including methane, in the next phase of the EEDI to limit emissions from new LNG-fuelled ships.”
The University Maritime Advisory Services (UMAS), part of University College London (UCL) and one of the organisations taking part in the research believes that national governments need to play a greater role in reducing shipping’s emissions if it is to meet the IMO’s 2050 goal of cutting emissions by at least 50 per cent compared with 2008 levels.
“It’s notable that improvements in fuel efficiency have slowed since 2015, with annual improvements of only 1 to 2 per cent,” said Dr. Dan Rutherford, marine program director at the International Council on Clean Transportation. “Policies are needed to accelerate innovative fuel-efficiency technologies like wind-assist and hull air lubrication, along with new, low-emission and zero-emission fuels.”
Elena Hauerhof, UMAS, leader of the inventory work, said: “This study represents a significant step forward in estimating emissions inventories, and for the first time uses a fully IPCC -aligned approach to estimate international shipping emissions. The study has also significantly advanced the accuracy of AIS based estimations for any ship, and evidences this by undertaking a detailed validation against fuel consumption and other key parameters reported in EU MRV for over 9000 ships.”
The list of Consortium members led by CE Delft includes:
- Dalian Maritime University
- Fudan University
- Institute of Economic Research Foundation, University of São Paulo
- Manchester Metropolitan University
- National Maritime Research Institute, National Institute of Maritime, Port and Aviation Technology
- Purdue University
- The International Council on Clean Transportation
- UMAS, University College London