Total shipping industry emissions grew by almost 10 percent from 2012 to 2018, accounting for 2.89 percent of total global anthropogenic emissions, according to the fourth International Maritime Organization (IMO) greenhouse gas study, the executive summary of which was published last week.
The data suggests shipping's share of emissions edged up over the period from around 2.76 percent of the global total in 2012, as global trade grew and other sectors began to curb their emissions.
International shipping's CO2 emissions also increased in the same time period, although at a slower rate than the industry overall, growing 5.6 percent from 701 million metric tons to 740 million metric tons.
The study marks the first time the specific emissions share of international shipping has been calculated, using a new voyage-based allocation method that the IMO claims "is exactly consistent with the IPCC guidelines and definitions."
Total greenhouse gas emissions from international shipping should be reduced by at least 50% by 2050 compared to 2008, the IMO Strategy on Reduction of Greenhouse Gas (GHG) Emissions from Ships stipulated.
The analysis also confirms that while total emissions have grown, the carbon intensity of shipping improved between 2008 and 2018 — both for international shipping as a whole and for most ship types. Overall carbon intensity, as an average across international shipping, was between 21 and 29 percent lower in 2018 than in 2008, the figures show.
Most of this progress was made between 2008 and 2012, however, with progress on improving the carbon intensity of international shipping slowing markedly in recent years. Since 2015, average annual improvements have ranged from just 1 to 2 percent, the analysis shows. The new study marks the first time that carbon intensity estimates have been included in the IMO's reporting.
The figures come from the fourth GHG overview from the IMO, the first to be released since the adoption of the IMO Strategy on Reduction of Greenhouse Gas (GHG) Emissions from Ships in 2018, which committed the body to pursuing a reduction in the carbon intensity of international shipping by at least 40 percent by 2030, while aiming for a 70 percent reduction by 2050, compared to 2008 levels. Total greenhouse gas emissions from international shipping should be reduced by at least 50 percent by 2050 compared to 2008, the strategy stipulated, with efforts made to ensure emissions peak as soon as possible and start declining before 2023.
However, meeting these targets remains a major challenge, the new study shows. Emissions from international shipping are continuing to grow on an annual basis and while improvements are being made on carbon intensity, a range of long-term economic and energy business-as-usual scenarios outlined in the IMO's study suggest that shipping emissions could represent 90 percent to 130 percent of 2008 emissions by 2050 — far off the target of achieving total emissions reductions of 50 percent.
The new figures will fuel concerns among campaigners that not enough is being done to bring the shipping industry in line with global climate goals. Regulations approved at the end of last year laid out how ships' carbon intensity will be measured and assessed as the industry works towards the 2030 goal of reducing carbon intensity by 40 percent. However, green campaigners were quick to criticize a dearth of robust enforcement mechanisms from the IMO and national government, while proposals to give non-compliant ships a full three years before needing to publish a plan for delivering operational efficiency improvements were slammed by activists.
Transport & Environment, WWF, Seas at Risk, and Pacific Environment all responded to the agreement by warning that it undermined a number of the goals contained in the IMO's landmark 2018 strategy, including pledges to reduce emissions before 2023, to ensure peak emissions "as soon as possible," and to put the shipping sector's carbon emissions on a pathway consistent with the Paris Agreement goals, with Clean Shipping Coalition President John Maggs labelling it an "act of extreme folly."