A closer look at ships

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How environmentally damaging are container ships? It’s not a simple question. With the help of professionals in Schaffhausen, we’ve found a clear answer: they cause less damage than the cultivation of food that is transported by ship.

Containerships at the port

Container ships pollute the environment. In terms of environmental pollution, ship transport is hardly relevant for the overall ecological footprint per kilogram of food.

The largest cargo ships in the world can transport over 20,000 containers at a time. These ships are close to 400 metres long and 60 metres wide. Their engines generate up to 80,000 HP.

Of course, not all container ships are so enormous. The 6,137 cargo ships travelling the world right now according to Alphaliner still have one thing in common though: they release CO2 and other greenhouse gases, as well as nitrogen oxides, sulphur oxides, fine particles and soot.

Chemicals from the paint on the hulls end up in the ocean. Coolants, machine oils and cleaning agents can leak out. In ballast tanks and on the ship’s side, living beings tag along for the ride, displacing native species and affecting entire ecosystems.

If all this sounds like rather dirty business, that’s because it is.

But just how dirty are these ships? What does this mean for gebana products? What impact does this have on their ecological footprint? These are complicated questions! That’s why we asked the Swiss consultants at ESU-services for guidance.

Based in Schaffhausen, the company’s team helped us by sifting through numerous studies, databases and specialised literature. In the end, their extensive analysis confirmed our assumptions:

  1. From a global perspective, ships are relevant in terms of their impact on climate, the environment and health.
  2. Transport by ship plays a negligible role when assessing the ecological footprint of a product.

Container ships only represent a quarter of international shipping

Let’s take a look at the numbers that ESU-services has compiled: in 2012, international shipping caused 2% of global CO2emissions and other greenhouse gases such as methane, nitrous oxide and fluorocarbons. Container ships make up around a quarter of international shipping, generating roughly 0.5% of global emissions.

According to organisations such as the German Nature Conservation Union, this view is too one-sided. On its website, it is argued that figures on CO2emissions are not enough to assess the ecological footprint of container ships. Nitrogen oxides, sulphur oxides, fine particles and soot are, at the very least, just as relevant. In fact, they are more dangerous than CO2.

Higher Emission Values for Nitrogen and Sulphur Oxides

The criticism of the Nature Conservation Union seems justified: in 2015, international shipping emitted 12.5% of global nitrogen oxide emissions and 9% of sulphur oxides. To that, add 2.5% of the fine particles blown into the atmosphere worldwide and 6% of the soot particles. The container ships alone were responsible for around a quarter of these emissions.

Nitrogen and sulphur oxides damage the human respiratory tract and impair plant growth and ecosystems in the water due to acid rain. They can also lead to excessive and therefore harmful plant growth (eutrophication). Fine particles and soot reduce air quality and contribute to respiratory diseases. It would be important that ships emit less of these pollutants, especially near the coast.

Lower Limit Values ​​in Effect Since Early 2020

The political sphere is taking notice. Since the beginning of 2020, fuels or exhaust gases from ships may only contain a maximum of 0.5% sulphur. That is still too much as far as the Nature Conservation Union is concerned. The organisation is calling for limit values ​​of 0.005%. The new regulation still represents a significant improvement compared to 2019, when the applied limit was 3.5%.

There are also so-called Emission Control Areas, including the North and Baltic Seas as well as a large segment of the North American coast. The limit in these areas has been 0.1% since 2015. Measurements in Hamburg showed that around 95% of the ships complied with the values in the year following the introduction of the new limits.

The Importance of Comparing With Other Means of Transportation

All these figures help us understand the impact of container ships, but only to a certain extent. That’s why we need to compare them with other means of transportation. Let’s try to be a little more specific.

Suppose we take one kilogramme of a product and transport it overseas to Europe, once by ship and once by plane. Let’s also take into account the transport from the production site to the airport and seaport, as well as from the point of arrival to the shop in Europe.

  • Scenario 1: Ship
    The total distance in this scenario is 10,295 kilometres. The ship travels 9,000 kilometres. The product is also on a train for 360 kilometres, and on the road in a truck for 935 kilometres.

  • Scenario 2: Plane
    At 7,495 kilometres, the total distance in this scenario is shorter than transport by ship. This is because the aircraft can fly in more or less a straight line. In this scenario, the plane covers 7,000 kilometres. The remaining 495 kilometres represent transport to and from the airport by truck.

Now, let’s evaluate each scenario using two separate criteria:

  • Criteria #1 – Environmental Pollution
    This assessment considers the resources used for transport as well as total pollutant emissions. This includes water and energy consumption, mineral and land use, climate change, ozone layer depletion, air pollutants and dust, air pollutants that cause cancer, water pollutants, noise and radioactive substances.

  • Criteria #2 – Climate Change Contribution
    This assessment strictly considers greenhouse gas emissions. The calculation takes into account CO2, methane, nitrous oxide and fluorocarbons.

Results Using Criteria #1

Air transport causes 20 times more pollution than transport by ship:

  • Plane
    In this scenario, 93% of the distance is travelled by plane, causing 98% of the environmental impact.

  • Ship
    In this scenario, 87% of the itinerary is by ship, accounting for 38% of the environmental impact. Transport by truck causes 57%, while 5% can be attributed to the train.

Results Using Criteria #2

The aircraft makes a 55-fold greater contribution to climate change compared to the ship, causing 99% of greenhouse gas emissions. In scenario #2, the ship is responsible for 36% of the emissions, the biggest offender being the truck, which is responsible for 59%.

Conclusion: Environmentally, the efficiency of the mode of transportation plays a more crucial role than the distance travelled.

Cultivation pollutes the environment far more than transport

Things become interesting when we look at the ecological impact of individual foods instead of the means of transportation. Let’s consider almonds, chocolate, coffee, bananas, and rice.

Transport by container ship is only responsible for 0.4 to 6.8% of the environmental pollution associated with one kilogramme of these products. Other means of transportation like trucks cause 1.3 to 10.3% of the pollution.

The majority of environmental pollution can be attributed to cultivation. With bananas, cultivation causes roughly 75% of the pollution per kilogramme of fruit. For coffee and rice, the number exceeds 90%.

Conclusion: Yes, ships are an environmental burden. However, transport by ship hardly affects the overall ecological impact per kilogramme of food.

Shipping Is Getting Better

These calculations don’t change the underlying problem: ships are dirty and they have to get cleaner. That’s why the International Maritime Organization, a special UN agency, adopted new reduction targets for container ships in 2018. The targets were originally valid for 2025, but are now binding as of 2022. From then onwards, depending on their size, newly built container ships must be 30 to 50% more energy-efficient than those built in 2014.

Initiatives such as the Clean Shipping Index or the Environmental Ship Index rely on financial incentives. The initiatives collaborate with ports that offer shipping companies discounts or other advantages if they have their ships assessed and certified for their environmental impact by the organisations. The better a ship is rated, the more favourable conditions it receives from the participating ports.

As for us, we concentrate on the things that we can really influence for the time being: the beginning and the end of the supply chain. From our point of view, these are the most important factors that shape the ecological footprint of our products.

We influence these factors by changing the rules of the game together: we trade differently, you buy differently. We produce more sustainably and fairly, you order large packages to be shared with friends and family to avoid food waste.


The complete study by ESU-services can be downloaded here.

Sources used

Environmental pollution of ship transport: Fact sheet for public discussion – a study carried out by ESU-service on behalf of gebana

Reducing greenhouse gas emissions from ships, International Maritime Organization (http://www.imo.org/en/MediaCentre/HotTopics/Pages/Reducing-greenhouse-gas-emissions-from-ships.aspx, abgerufen am 30/07/2020)

Emission Control Areas, Wikipedia (https://de.wikipedia.org/wiki/Emission_Control_Area, abgerufen am 30.07.2020)

Container ship, Wikipedia (https://de.wikipedia.org/wiki/Containerschiff, accessed on 30/07/2020)

Photo: Andy Li, https://unsplash.com/photos/CpsTAUPoScw