The rule, Regulation 14 in Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL), took effect globally in January 2020, targeting harmful emissions at shipboard sources by setting the maximum allowable sulfur content of fuel oil burned by seagoing vessels at 0.5 percent. That’s down from a 3.5 percent cap in place since 2012. An amendment to Regulation 14, in effect since March 2020, prescribes the same level to all fuel carried on board those vessels. The usage limit is even stricter, at 0.1 percent, within designated emission control areas (ECAs), which encompass most territorial waters and economic exclusionary zones of the United States. These standards are part of a broader scheme promulgated by the International Maritime Organization (IMO), a specialized agency of the United Nations (UN), through MARPOL, the principal environmental regulatory code applicable to the global shipping industry.
Historically, most ships sailing the world’s oceans––from supertankers to container ships to roll on/roll off carriers and others––had been powered by lower-grade residuals. Last year the IMO estimated a 70 percent cut in sulfur oxide emissions from ships because of the new 0.5 percent mandate. Exposure to sulfur oxide emissions has been linked to respiratory, cardiovascular, and lung disease, and emissions can lead to a litany of environmental impacts, both on land and at sea. A study in 2016 by the Finnish Meteorological Institute projected the latest cap would reduce emissions by more than 8 million metric tons annually and prevent some 570,000 premature deaths over five years, yielding outsized benefits in coastal communities and areas proximate to major shipping lanes.
In the lead-up to 2020, though, speculation swirled among public and private stakeholders, wary of low supplies and the high costs of compliant bunkers, which include very low sulfur fuel oil (VLSFO) blends, and marine gas oil (MGO) and marine diesel oil (MDO) distillates. As the compliance deadline loomed, the IMO sought to assuage concerns, issuing safety guidance and monitoring reports of compliant fuel non-availability, submitted under Regulation 18 of Annex VI. New reports suggest a smooth transition. As of February, the IMO had fielded just 61 fuel oil non-availability reports (FONARs), indicating supplies have been strong. IMO sampling data was likewise encouraging. Of 136,938 samples taken from 116 million tons of residual fuel supplied for use onboard ships in 2021, nearly 75 percent did not exceed 0.5 percent sulfur content. Of 85,097 samples from 15 million tons of distillate fuel, more than 99 percent did not exceed 0.5 percent. And research prepared in the fall by Oak Ridge National Laboratory–– which characterized compliance as “near universal”––showed VLSFO had been the most-sold petroleum-based bunker fuel at ports in Singapore and Rotterdam after the rule took effect, attributable in part to a narrower-than-expected price spread between VLSFO and the 3.5 percent high sulfur fuel oil (HSFO).
Importantly, alternative means of compliance, such as installing exhaust gas scrubbers or using biofuels, are permissible under MARPOL, enabling ships equipped with such systems to burn fuels of a higher sulfur content. As of February, the IMO had received 3,765 reports of ships equipped with exhaust gas cleaning systems, a 19 percent increase since March 2021, along with 13 reports of biofuel-powered vessels. The use of alternative fuel sources––liquefied natural gas (LNG), methanol, hydrogen, ammonia, etc.––is expected to increase over the long-term, as outlined recently by researchers from the University of Saskatchewan.