Exposé from today's Guardian:
Carbon dioxide emissions from shipping are double those of aviation.
Separate studies suggest that maritime carbon dioxide emissions are not only higher than previously thought, but could rise by as much as 75% in the next 15 to 20 years if world trade continues to grow and no action is taken. The figures from the oil giant BP, which owns 50 tankers, and researchers at the Institute for Physics and Atmosphere in Wessling, Germany reveal that annual emissions from shipping range between 600 and 800m tonnes of carbon dioxide, or up to 5% of the global total. This is nearly double Britain's total emissions and more than all African countries combined.
Carbon dioxide emissions from ships do not come under the Kyoto agreement or any proposed European legislation.
Aviation carbon dioxide emissions, estimated to be about 2% of the global total, have been at the forefront of the climate change debate because of the sharp increase in cheap flights, whereas shipping emissions have risen nearly as fast in the past 20 years but have been ignored by governments and environmental groups. Shipping is responsible for transporting 90% of world trade which has doubled in 25 years.