The shipping industry is the backbone of the global economy, carrying over 80% of all trade. Although, as an industry, it is more carbon efficient than road or air shipping, shipping is still responsible for a considerable amount of greenhouse gas emissions. If added to the list of nations by emissions, shipping would be the world’s sixth-biggest polluter. Furthermore, the Third IMO GHG Study of 2014 predicted that this could rise by 250% by 2050 if no changes are made. So, what is causing this pollution from shipping, and what can be done to address it and provide more sustainable vessels?
Sources of Pollution from Shipping
There are several ways in which shipping produces pollutants, so we’ll break them down here into a few categories.
Red Codee Alarm and Climate Change
In his reference to the 2021 Intergovernmental Panel on Climate Change (IPCC) report, the UN Secretary-General António Guterres said, “it is clear to all who want to listen that the planet is facing a climate crisis.” He elaborated that this is “a code red for humanity. The alarm bells are deafening and the evidence is irrefutable”. By extension, the climate crisis creates an ocean crisis, directly increasing the risks for marine biodiversity.
Sulfur Dioxide
Most ships are powered by heavy fuel oil, the most polluting form of fuel oil. According to Peter Boyd, chief operating officer of Carbon War Room, “One ship emits the equivalent of 50m cars’ worth of sulfur dioxide (SO2) emissions, and just 15 ships emit the equivalent SO2 emissions of every car in the world.” Sulfur dioxide is a cause of respiratory illness in humans and causes acid rain, which kills trees and leaches vital minerals from the soil.
Carbon Dioxide
A vast amount of CO2 is produced by burning fuel oil for shipping. Carbon dioxide is a greenhouse gas and a significant contributor to the ongoing climate crisis. The annual CO2 emissions from shipping are currently estimated to be around 940 million tons, at least 2.5% of total global CO2 emissions.
Fuel Sillage
We may occasionally hear of major oil spills from tankers, which have individually devastating environmental impacts. However, there are also thousands of minor spills annually, and not just from fuel tankers. Some occur in ports during the fuelling process or when loading tankers; other incidents occur during collisions or when ships become beached. These seemingly minor incidents are cumulative, leading to a great deal of environmental damage and harm to marine life.
Making Shipping More Sustainable
The shipping industry as a whole is aware of sustainability issues, and there are initiatives in place now seeking to address them. For example, the International Maritime Organization has set a target to cut CO2 emissions by 50% by 2050.
Another factor that had been hampering efforts to reduce the impact of shipping on climate change was that most nations don’t include international shipping on the carbon budget. However, this too is beginning to change, and the UK became the first country to have CO2 from international shipping in its CO2 budget in 2021. In addition, many innovative solutions for sustainable vessels are also being planned by independent businesses.
Cleaner Fuels
Cleaner distillate fuels are a way to reduce the sulfur dioxide emissions from shipping. However, these fuels are at least $300 per tonne more expensive than the fuels currently used, so this would have a dramatic financial impact on shipping companies that make the switch. So it would seem that, without international cooperation regulating fuel usage, this option is unlikely to be taken up at present. Fuel-use reduction would seem to be a more workable option in the short to medium term.
Biocide-Free Paint
Most ships have reduced fuel efficiency due to a build-up of marine organisms on the hull. This can be improved by a coat of paint that inhibits the growth of these organisms, an option that is beginning to be taken seriously. For example, AIDA Cruises’ 38,531gt cruise vessel, AIDAcara, received an application of this paint in 2019 when drydocked in Marseilles, France. The paint manufacturer, Nippon Paint Europe, estimates that it can reduce fuel consumption by up to 10%, providing more sustainable vessels.
Conclusions
The climate crisis is being taken more seriously than ever, and the shipping industry is working hard to produce ever more sustainable vessels. However, there is still a lot of work to be done, and we can expect to see an increasing number of innovative solutions in the coming years.