Martin Placek
Research expert covering transportation and electronics
Green maritime shipping - statistics & facts
The shipping sector has long been in the spotlight for its detrimental impact on the environment. In addition to particulate matter, ships’ engines emit sulfur oxides (SOx), nitrogen oxides (NOx), and greenhouse gases (GHG), most notably carbon dioxide (CO2). It was estimated that in 2018, shipping accounted for almost 11 percent of all transport-related CO2 emissions in the world.
Discharge of untreated ballast water, which used to be common practice, is another environmental problem of this industry. Furthermore, at the end of their life cycle, ships are often dismantled in yards located in developing countries, a practice which comes at great human and environmental costs.
However, the increasing use of scrubbers brings about a new problem. Scrubbers remove pollutants by spraying seawater over the ship’s exhaust gases. This mixture of seawater and pollutants – called scrubber wash water – is then discharged overboard, where it can damage marine ecosystems. The concentration of scrubber wash water is especially high in ports, driving some countries to ban wash water discharge in their ports.
International regulations putting limits on emissions
As a response to these issues, environmental regulations in the shipping sector are becoming increasingly stringent. In September 2017, the Ballast Water Management Convention came into force. More recently, the International Maritime Organization's (IMO) 2020 regulation put a cap on the maximum sulfur content allowed in maritime fuels. The shipping industry has been one of the greatest emitters of sulfur dioxide, which can cause respiratory issues in humans, as well as the formation of acid rain and particulate matter. In an effort to curb SOx emissions, the IMO established a cap of 0.5 percent m/m (mass by mass) on marine fuels. Alternatively, ships that still use heavy fuel oil (HFO) must install exhaust gas cleaning systems (also known as scrubbers) to comply with the emissions reduction standards.However, the increasing use of scrubbers brings about a new problem. Scrubbers remove pollutants by spraying seawater over the ship’s exhaust gases. This mixture of seawater and pollutants – called scrubber wash water – is then discharged overboard, where it can damage marine ecosystems. The concentration of scrubber wash water is especially high in ports, driving some countries to ban wash water discharge in their ports.
Rise of alternative maritime fuels
Overall, the IMO 2020 sulfur cap is expected to have far-reaching consequences on the marine bunker industry. Already in 2020, there was a considerable shift towards using Low Sulfur Fuel Oil (LSFO). This trend raises questions about the potential market leaders in the production of LSFO. China, which has the second-largest oil refining capacity in the world, has been intensively preparing to become self-sufficient in the production of LSFO. Aside from conventional fuels, alternatives such as liquefied natural gas (LNG), which has a negligible sulfur content, are also becoming increasingly appealing. Pioneering concepts such as ammonia-fueled ships and electric propulsion are also part of the effort to decarbonize the shipping industry. A lack of infrastructure and higher costs compared to HFO are, however, hindering their take-off. Nevertheless, this should change in the coming years: it is expected that by 2030, operating a container ship fueled by low- or zero-carbon fuels will cost almost as much as operating an HFO-fueled ship.
