An assessment of technologies for reducing regional short-lived climate forcers emitted by ships with implications for Arctic shipping

Evaluating potential cost–effectiveness of abatement technologies in parallel with emerging scientific evidence is important for better management decisions related to integrated environmental problems. This article evaluates six black carbon (BC) emissions reduction technologies for marine engines, including the net effect on a set of short-lived climate forcers from marine diesel combustion. Technologies evaluated include slide valves, water-in-fuel emulsion, diesel particulate filters, low-sulfur fuel, emulsified fuel and sea water scrubbing. Cost–effectiveness values for these technologies implemented alone or in combination are reported in terms of US$/metric ton (mt) for BC, particulate matter and CO2 equivalents (CO2eq), with the latter including CO2 emitted directly due to parasitic fuel use and both warming and cooling short-lived climate forcers affected by control technology performance. The article finds that the most cost-effective strategy evaluated (i.e., the least US$/mt CO2eq) occurs through a combination of technologies that achieve an approximate 60% BC reduction. Using the example of Arctic shipping, the cost to achieve this 60% BC reduction target may be approximately US$8–50 million per year, avoiding approximately 9–70 million metric tons CO2eq per year. Uncertainty analysis using Monte Carlo simulation is used to demonstrate the robustness of these results.