The new study combines global ship operations (AIS) data with detailed vessel characteristics for more than half a million ships to estimate GHG emissions and air pollution from shipping at high resolution on an hourly basis for the years 2013 to 2015.


  • Maritime fuel consumption increased from 291 to 298 million tonnes (+2.4%) from 2013 to 2015, compared to a 7% increase in shipping transport work.
  • Carbon dioxide (CO2) emissions from global shipping increased from 910 to 932 million tonnes over the same period.
  • Three ship classes accounted for more than half of CO2 emissions: container ships (23%), bulk carriers (19%, oil tankers (13%).
  • Six flag states (country of registration) account for 66% of the global shipping fleet’s deadweight tonnage: Panama (15%), China (11%), Liberia (9%), Marshall Islands (7%), Singapore (6%), Malta (5%)


Credit: ICCT

According to the study, improvements in ship efficiency were less that the increases in transport supply over the period studied, resulting in higher GHGs and air pollution.

In addition, while average speeds remained largely flat between 2013 and 2015 for most ships, the largest oil tankers and container ships sped up nearly 4% and more than 11%, respectively. The study also identifies black carbon as the second most important climate pollutant after CO2, representing between 7 and 21% of the total climate impact of shipping.

Naya Olmer, lead author of the study, noted:  “When IMO last looked at this in 2014, shipping emissions had dropped after the Great Recession. We now know that the pendulum has swung back, with emissions again on the rise as global trade expands.”

Credit: ICCT

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