Study sounds alarm on black carbon in VLSFO emissions

As the International Maritime Organization (IMO) grapples with controlling the shipping industry’s use of heavy fuels, substituting very-low-sulfur fuel oil (VLSFO) may do more harm than good — at least in the Arctic.

That’s because some of the more aromatic blends of VLSFO may drastically increase — by up to 85 percent — emissions of black carbon, the term used for carbon compounds laden with dark sooty particulates. A recent study in Germany and Finland that reached this conclusion was put before the IMO’s Subcommittee on Pollution Prevention and Response (PPR 7) in February in London.

Sian Prior, a marine science and policy specialist and lead adviser to the Clean Arctic Alliance, a coalition of 18 nonprofit groups, explained why black carbon emissions are particularly threatening in the region.

“Black carbon doesn’t stay in the atmosphere long and settles onto snow and ice, and it’s warm and therefore increases the melt,” she said. “It’s dark, so it attracts sunlight. And where it does melt, the surface of rock and water is darker too, and attracts more sunlight, creating a never-ending cycle.”

The Clean Arctic Alliance is in the process of commissioning more research on the various blends of VLSFO, and gaining a better understanding of the previous study funded by the German Environment Agency. That will take critical time and the risks of environmental damage will increase, all while another substitute is already available, Prior said.

“Even if it turns out that black carbon from very-low-sulfur fuels is of lesser concern, we still want to move toward requiring ships to use safer distillate fuels in the Arctic, and to install filters that can reduce black carbon by over 90 percent,” she said.

IMO spokeswoman Natasha Brown said the International Standardization Organization (ISO) told panelists at PPR 7 that it is already in the process of monitoring the properties of VLSFO and high-sulfur fuel oil. 

Brown said the ISO also established a group to advance the development of a standardized sampling protocol to make accurate and comparable measurements of black carbon emissions, and to investigate links between measurement systems and policy options.

By Professional Mariner Staff