The US National Oceanic and Atmospheric Administration took emissions readings from a commercial container ship using high-sulphur fuels, and then compared them to readings from the same ship using low-sulphur fuels and reducing its speed from 22 knots to 12 as it neared the California coast.
The comparison showed emissions of sulphur dioxide and particulate matter dropped dramatically – by more than 90%. Black carbon emissions were also down by an average of 41%, although the net effect was a slightly warming effect.
T&E programme manager Bill Hemmings said: ‘This study provides dramatic evidence of the strong air quality benefits of low-sulphur fuels and of slow steaming near coasts. Some ship operators in northern Europe are objecting to the forthcoming application of International Maritime Organisation regulations on low-sulphur fuels because of the higher fuel costs and unfounded fears of losing competitiveness. But unless things change, shipping will become the biggest source of SOx and NOx pollution in Europe by 2020.’
In a separate development, the Danish shipping giant Maersk has called on the International Maritime Organisation to extend its obligatory energy efficiency standards to the entire shipping fleet. The new standards, agreed in July, will only apply to new ships.