Needs and opportunities to reduce black carbon emissions from maritime shipping

Published: 2015.03.24

Alyson Azzara, Ray Minjares, and Dan Rutherford

Ports and marine vessels are major sources of diesel particulate matter and black carbon. There are growing concerns about the impacts that air pollution from shipping has on the environment, particularly in the Arctic region.

Some members of the International Maritime Organization have argued that since shipping contributed only 2% to global BC emissions in 2000, the IMO should cease development of potential control measures. This argument underestimates the importance of marine BC emissions.

This study presents an analysis of the contribution of shipping to the global diesel black carbon inventory, which scientists believe has a disproportionate warming effect compared to other sources of black carbon. The results indicate that marine black carbon emissions were 8%–13% of all diesel emissions in 2010, and suggest that the marine sector will maintain and perhaps increase its share of diesel black carbon emissions by 2030.

Recent studies indicate that 80% of shipping emissions occur in the Northern Hemisphere, and that emissions above 40°N can significantly impact climate forcing and ice/snow melt in the Arctic. These unevenly distributed emissions can lead to substantial impacts on the greater Arctic region. As a major global source of black carbon, diesel engines present a promising opportunity for mitigating climate pollution. A combination of currently available technologies and well-established best practice can prevent up to 90% of diesel particulate and black carbon emissions from marine engines.