How Can We Reduce Shipping’s Carbon Footprint?

by Senior Writer, Laura Stoškutė.

Three ways to reduce the carbon emissions of shipping.

Air pollution is one of the most serious issues faced today, and shipping is part of the problem. Reducing carbon emissions and fuel consumption is a major priority for the marine industry. According to the International Maritime Organisation (IMO), shipping emits less carbon dioxide (CO2) than trucking industry or aviation, in terms of carbon emissions per ton per mile. 

However, from the international shipping industry point of view, the overall CO2 emission remains high compared to other means of transport. International shipping alone represents around 3% of global anthropogenic COemissions – nearly the same as that emitted from the aviation industry. What is more, ships emit other pollutants into the air, mostly in the form of sulphur dioxide (SOx), nitrogen oxides (NOx) and other particulate matter that endanger human health. 

As a consequence, international organisations and regulators are building strategies that would allow cutting emissions and pollutants significantly in the shipping industry. In fact, the latest strategy from IMO envisages reducing the total CO2 emissions by at least 50-70% by 2050, and phasing them out entirely by the end of this century. In addition, from January 2020, the IMO has limited all marine fuel to 0.5% sulphur content. 

What are the most viable options?

Going green requires big investments in vessels, shipping infrastructure and innovation. So what are the most feasible ways to reduce the shipping’s carbon footprint in the near future? 

1. Switching to alternative fuels

To reduce emissions, vessels can switch to “greener” fuels. The following are some of the most promising alternatives. 

Ammonia – a carbon neutral fuel, ammonia is usually produced by using hydrogen obtained by reforming natural gas. The cases of producing hydrogen particularly for carbon-free ammonia production have recently increased.  In addition, ammonia is expected to have low production, storage and transport costs. Viking Energy, built by Norwegian shipping company Eidesvik and oil and gas group Equinor, will be the first ship to run entirely on ammonia fuel cells at its launch date in 2024.

Methanol – another promising alternative fuel that contains no sulphur and low emissions of NOx, as a clean burning alcohol, is methanol. Methanol is widely available and distribution does not differ much from conventional fuels. As of today, methanol is used as a transportation fuel on a significant basis for cars in China, where it is cheap and readily available. The use of methanol in the maritime industry is currently limited, however, it remains a valuable low-emission option.

Liquefied natural gas (LNG) –  this fuel presents an alternative for simultaneous application with fossil fuels derived from crude oil, for example, diesel. LNG has been used on a major industrial scale for several decades now. However, in recent years LNG has attracted increasing interest in the energy industry and beyond, as a new energy for applications at consumer level.

Other energy sources – wind and solar power, batteries, biofuels and hydrogen are being tested for use in shipping, and many experiments are taking place. Although they are not viable for commercial ships yet, these technologies have potential for future utilisation.

2. Slow steaming

Slow steaming refers to the practice where the operational speed of the ship is reduced thus reducing their fuel consumption, reducing CO2 and other pollutant emissions. It is estimated that reducing ship speed by merely 10% reduces vessels’ emissions by third. This colourful infographic by Transport & Environment shows how a minor 20% reduction in ship speed could have a massive and significant impact on the climate and environment. 

The purpose of slow steaming is not only reducing CO2 emissions as well as NOx and particulate matter but also it is also the most cost-effective way to reducing CO2 emissions as it can be done at almost no cost. Maersk Line – the world’s largest container shipping company – have been using slow steaming since 2007, decreasing engines’ speed by 35% thus bringing fuel savings and reducing costs for ship maintenance and operation issues. The company targets to reduce 60% in emissions per container by the end of 2020. 

3. Shore power

Shore power, also called cold ironing or alternative marine power, is the process of providing electrical power from the shore to a ship while at port (thus shutting off the ship’s diesel-fueled auxiliary engines). The greatest benefit of shore power is that this method reduces SOx, NOx and particle discharge emissions by nearly 90% and can also diminish COemissions and improve air quality.

Other great benefits of cold ironing include a reduction in noise pollution, as well as a reduction in lifecycle cost by fuel consumption and maintenance cost. Some large ports have already implemented the shore power solution, among which are Port of Los Angeles, Port of Long Beach, Port of Seattle, Port of Antwerp, Port of Killini (Greece). 

Laura Stoškutė

Laura Stoškutė is a Senior Writer at CleanTech News and a startup enthusiast with a passion for building sustainable businesses. Laura joined the CleanTech News team with a mission to help spread the word about young and growing companies working towards a greener and better future. Her diverse experience drawn from tech companies across financial, legal and energy sectors informs her creative approach to work. She enjoys meeting new people and hearing new perspectives from business owners who create environmentally-friendly products or services and encourage social good.