“To scrub, or not to scrub” has been an ongoing debate in the maritime industry, especially following the entry into force of the 2020 sulfur cap. Many ports and countries have decided to ban open-loop scrubber discharges within their territorial waters, although there are no uniform regional or global legislations that prohibit the use of exhaust gas cleaning systems (EGCSs).
Back in January 2020, a new global fuel sulfur cap of 0.5% came into force. Shipowners had been given several options to comply with the new regulation, the most common being installing scrubbers, using blended very low sulfur fuel oils (VLSFO), or distillates–marine gas oil (MGO)/marine diesel oil (MDO). Whichever solution was chosen, there were additional costs for shipping companies.
The use of scrubbers has split the shipping industry, with many environmental NGOs and research institutes emphasizing side effects of this technology and claiming that air emissions were reduced but sea pollution increased.
CSA: This recent announcement was disappointing, especially as there doesn’t appear to have been a risk assessment behind it, which the IMO strongly recommends before implementing any EGCS restrictions.
Of course, we have seen reports from Swedish sources over the years questioning the environmental impact of EGCS, but none with definitive results. So, with no risk assessment or any hard evidence of environmental harm, this appears to be a restriction for precautionary reasons, without clear environmental benefit.
Today, approximately 4,000 ships globally (about 8% of the global fleet) are fitted with EGCS, which provide a practical, transitional solution to the alternative fuels which are not yet ready . Local restrictions on these should have strong evidence for cause.
CSA: The primary operational impact will be the requirement for vessels to change fuels prior to arriving in Swedish waters, which at minimum is a great inconvenience, especially for large ships in this high traffic environment, day and night, and in all weather conditions. Of course, all vessels transiting the Danish Straits and not bound for Sweden should be able to continue operating EGCS during that passage.
Scrubber technology was supported by the European Union and Commission in line with the IMO’s global sulphur cap which came into force on 1st January 2020. It was included in the EU Sulphur Directive, still in force today, as an alternative means of reducing sulphur emissions and harmful particulate matter. As a result, the shipping industry invested in it.
CSA: We’d like to believe that this decision in isolation will have little effect. However, EGCS is an essential element of a mature CCS, because any vessel using carbon-based fuels will require exhaust pre-treatment.
As early CCS onboard testing shows potential for helping achieve IMO targets for capturing CO2, the EGCS/CCS combination is increasingly seen as an important technical path while waiting for e-fuels. With that in mind, some of our members are right now actively developing CCS which work together with existing scrubbers – the type of operational innovation that helps solve problems in the shipping industry.
However, the Swedish decision may impact their plans to continue development. There is an underlying principle at stake here: if scrubbers are banned without even a risk assessment when already endorsed and supported by international (and most national) authorities, this jeopardises related transitional technology by increasing risk for early adopters and investors.
CSA: Interesting question – where is the science on this? In fact, there are no studies with clear evidence of environmental harm from these systems, and very few states have even conducted risk assessments. The question we frequently ask ports or other authorities that are considering scrubber restrictions is whether they are basing it on science or something else – and it’s usually ‘something else’.
Studies or reports that support a scrubber ban are often well-publicised but are usually based only on literature reviews and assumptions, as they have very little actual data or experience with these systems. These reports point to the potential for problems, but there is no actual evidence of environmental harm. On the other hand, there is a significant body of scientific research supported by actual data which concludes that the operation of scrubbers does not harm the marine environment .
And, after 50 years of scrubbers in global maritime use, there is still no hard evidence anywhere of environmental harm.
CSA: All current restrictions / bans in ports or even port states that we know of are based on some form of the “precautionary principle”, which was originally designed to allow a protective position on something until the science was available to make a proper evaluation.
Today, the science for EGCS is available, the IMO has published guidelines on risk assessments, and these can be done affordably using local waters and the assistance of reputable technical experts.
The actual risk assessments conducted by IMO member states that we are aware of have found little or no risk to the environment from EGCS operations.