European Commission's Joint Research Centre (JRC) released a new "reference report" focused on reducing greenhouse gas (GHG) emissions from shipping. The report titled Regulating Air Emissions from Ships: The State of the Art on Methodologies, Technologies and Policy Options" provides an overview of methodologies for estimating air emissions from shipping, describes technological solutions and proposes policy options for reducing carbon emissions as well as SOx air pollution in this sector.
While recognizing that maritime transport has the lowest ratio of CO2 emissions per ton-km transported compared to other modes of transport, JRC identified shipping as a significant source of GHG emissions. Maritime transport produces around 1 giga-tonne per year of CO2—or about 4% of global man-made CO2 emissions–which makes its carbon footprint approximately as high as that of Germany's. By 2050, GHG emissions from global shipping are estimated to increase by 150-200%, to contribute as much as 15% of man-made CO2 emissions. There is no regulation of GHG emissions from international maritime transport yet, but this is under discussion in the International Maritime Organization (IMO) and at the United Nations Framework Convention on Climate Change (UNFCCC).
In addition, shipping is an important source of global SOx emissions. Sulfate emissions from shipping will increase by 10-20% over the main routes in 2012, contributing up to 5.2% to the total tropospheric sulphate burden. Sulfur levels in marine fuels are already regulated by the IMO. In Emission control Areas (ECA), the current sulfur limit is 1%, going down to 0.1% in 2015. Outside the ECAs, the current IMO limit is 4.5%, followed by 3.5% from 2012 proposed) and 0.5% from 2020 (proposed). The current global average sulfur level in marine fuels is 2.7%.
The report lists a number of technologies available to reduce carbon emissions from shipping. The technologies are grouped into categories depending on the specific sector in which they are implemented, including (1) ship design, (2) propulsion, (3) machinery, (4) operation and (5) fuel.
However, to achieve significant improvements in the reduction of carbon emissions and air pollution, technological solutions should be supplemented with other approaches, including regional and global market-based measures, JRC said. In particular, the report analyses the introduction a GHG Emission Trading Scheme (ETS) for the shipping sector at international level.