Key findings include:
- Fuel consumption is increasing. Maritime fuel consumption increased from 291 to 298 million tonnes (+2.4%) from 2013 to 2015, compared to a 7% increase in demand for shipping transport work.
- Three ship classes and six flag states account for more than half of emissions. Container ships (23%), bulk carriers (19%) and oil tankers (13%) accounted for more than half of emissions. Most CO2 emissions can be attributed to ships from Panama (15%), China (11%), Liberia (9%), Marshall Islands (7%), Singapore (6%), and Malta (5%).
- Black carbon is the second most important contributor to shipping’s climate impacts. BC represents 7% of total shipping CO2-eq emissions on a 100-year timescale and 20% of CO2-eq emissions on a 20-year time scale.
- Increases in efficiency have not absolutely reduced CO2 emissions from ships between 2013 and 2015. While the CO2 intensity of many major ship classes decreased (i.e., they became more efficient) from 2013 to 2015, total CO2 emissions from ships rose. Even in some cases where a ship class became much more efficient, their CO2 increased.
- The biggest ships are speeding up and emitting more. While average cruise speeds remained largely flat between 2013 and 2015, the largest oil tankers (>200,000 dwt) and the largest container ships (>14,500 TEU) sped up. The largest oil tankers increased their cruising speed over ground (SOG) nearly 4% and the largest container ships increased their cruising SOG more than 11%.
The report comes days before the latest round of UN IMO talks on CO2 in London, ahead of a proposed 2018 interim climate deal for the sector.