Ship owners participating in the Green Marine environmental certification program have managed to achieve a 1.4% average annual reduction in greenhouse gases (GHG) intensity.
The development was confirmed through Green Marine’s first carbon dioxide equivalent (CO2e) emissions data gathering and analysis on more than 250 vessels of various types, including tug, passenger and cargo ferry, bulk, self-unloading, tank, container, and articulated tug barge.
This initiative was undertaken to better gauge the environmental program’s impact since its launch 10 years ago.
“It is the first time this kind of reporting exercise has been done by such a diversified group of ship owners,” Dr. Eleanor Kirtley, Green Marine’s West Coast program manager, said.
Participants had to provide emissions data from a baseline year and from 2016. They subsequently each calculated their average GHG emissions for a period varying from two to eight years.
“We decided to aggregate the results by percentage of reduction since it was the only common metric for every type of ship owner,” Kirtley explains, adding that ship owners use different accepted methods of measurement, with some reporting emissions per unit of time, while others do so per tons of cargo or per unit of traffic work.
To reach an average annual reduction of 1.4%, the shipping companies had to implement significant changes to their operations. These include hull cleaning and propeller polishing, weather routing, loading for trim optimization, voluntary speed reductions, and preventive engine maintenance.