The Arctic, maritime shipping, and black carbon

On average, the Arctic is warming twice as fast the rest of the globe. This year, the summer extent of Arctic sea ice was the lowest ever recorded, and the rate of ice melt has been increasing. These changes have global implications, contributing to sea level rise and influencing atmospheric and oceanic circulation patterns in the Northern Hemisphere in ways that can lead to more extreme weather events and permanent shifts in global weather patterns.

These changes in the Arctic are due in part to emissions of black carbon. Black carbon is a dark solid particle emitted when any fossil fuel or biomass is burned, and a very powerful climate forcing agent. Because its warming effects are magnified when emitted onto or near ice and snow, black carbon emissions in the Arctic are particularly damaging. Since 1890, black carbon may have increased average temperatures in the Arctic by 0.5 to 1.4 degrees C.

Maritime vessels are among the most important sources of black carbon. Black carbon emissions from international shipping are entirely uncontrolled, and projections are that they will continue to increase in the northern polar region as more ice melts and new shipping routes become available. One estimate suggests that shipping emissions of black carbon in the Arctic will rise between 70% and 120% by 2030. That trend, coupled with the magnified effects of emissions there, highlights the importance of controlling those emissions—and the potential benefits of doing so quickly. A study now under review modelled the greenhouse effect from shipping emissions in the Arctic in 2030, excluding the effects from CO2 and N20. Preliminary results suggest that a 70% reduction in Arctic black carbon shipping emissions could reduce the greenhouse effect observed by 50%.

The International Maritime Organization (IMO), the United Nations agency responsible for regulating international shipping, is engaged in a long-term effort to reduce ship emissions, including black carbon, an effort to which ICCT staff have been contributing. Together with the Institute of Marine Engineering, Science and Technology (IMarEST) we have outlined a definition for black carbon and ranked different measurement approaches. We have also re-analysed global and Arctic estimates of black carbon emissions from international shipping, concluding that these underestimate global emissions by about 40% and Arctic emissions by about 90%.

Most recently we have been cataloging technology and operations strategies to reduce black carbon emissions. We’ve incorporated the results of this survey into a simple Excel database, available here, which we will continue to update. The database includes information on performance, application, and provider, as well as examples of these technologies/operational strategies in use. See the interactive map below for quick summaries.

The map above shows technologies and operations strategies categorized by their black carbon reduction potential level: red = Level 0 – Uncertain or Limited BC Test Data; yellow = Level I – 1-49% Reduction; green = Level II – 50-74% Reduction; and blue = Level III – 75-100% Reduction. The position of each point is based on the recent location of a ship with the technology or strategy in place.

GHG emissions