Article from Magasinet Grøn Omstilling, by Helene Chéret 

A small country, a large seafaring nation. Denmark has the world's fifth largest merchant fleet, surpassed only by Greece, Singapore, China and Japan. Unfortunately, this proud fleet has a serious flaw. The vast majority of our ships sail on heavy bunker oil – one of the world's most polluting fossil fuels.  

"The Danish politicians like to describe Denmark as a green pioneering country that builds wind turbines and sets high goals for the climate and the environment. But when it comes to shipping pollution of the sea, there is a worrying silence.” 

That's what Kåre Press-Kristensen says, who is a senior advisor at the Green Transition Denmark. In his opinion, Denmark should take responsibility as soon as possible and take the lead in preventing ships from emitting pollution on the scale they do today. Ships sailing on heavy bunker oil emit large amounts of tar matter, heavy metals, particles and gases. Part of the pollution flies via the air over land and causes damage to people and nature, while much of the pollution also smokes in the sea. The tar substances and heavy metals are concentrated in the seabed or absorbed by animals and plants and accumulate in the food chain, so that they can later end up in our shellfish and fish or damage our marine ecosystems. 

"The green transition is underway everywhere else in society. Why should shipping just be able to emit toxins into the air and into the sea? We cannot accept that. We are in the 21st century and yet we use the sea as a dumping ground,” 

Kåre Press-Kristensen, senior adviser at the Green Transition Denmark 

Scrubbers as a cheap solution 

In the longer term, according to Kåre Press-Kristensen, shipping must move away from fossil fuels and onto ammonia, made with the help of solar and wind energy. But right now it's all about reducing the emissions of sulphur, tar substances and particles from shipping. It requires the shipping companies to replace their current fuel, the heavy bunker oil, with less sulphurous bunker oil and clean the flue gas with both filters and catalysts. Unfortunately, the trend right now is quite different. It is connected with the fact that, from an international perspective, shipping was given a loophole when action was taken against sulfur pollution. 

Sulfur content in the air is harmful and can lead to respiratory diseases and death. Air pollution from shipping causes health damage in Denmark corresponding to half of the health damage caused by Danish sources of pollution on land. In order to reduce air pollution from shipping, the UN Maritime Organization, IMO, decided that from 2020 ships' fuel must contain no more than 0,5 percent sulfur, as opposed to the previous 2,5 percent outside low-emission areas. In low-emission areas such as in the waters around Denmark, the ships must use fuel that contains a maximum of 0,1 percent sulphur. However, it is still 100 times more sulfur than ordinary road diesel.  

And it is here that the shipping companies that own the ships are served an alternative that is of decisive importance for the green transformation of shipping. They can choose to sail on the expensive, more environmentally and climate-friendly fuel. Or they can sail on with the cheaper but more sulphurous fuel if they install so-called scrubbers on their ships. Scrubbers are sometimes called smoke scrubbers, but they do not remove the pollution. They mix smoke that would otherwise have been discharged through the chimney with seawater and dump all the pollution untreated into the sea. The flue gas water contains carcinogenic tar substances and toxic heavy metals.  

The consequence is that the number of ships with scrubbers has exploded in the last decade. 13 years ago there were a handful of ships with scrubbers - today over 4.000 ships use the technology. According to Kåre Press-Kristensen, it is close to catastrophic that they chose to give the shipping companies that option.   

"The sulfur requirements are absolutely necessary, and the sulfur level has dropped significantly in the air over Denmark since 2014," says Kåre.

By allowing scrubbers, they have legitimized that ships can continue to sail on one of the most polluted fuels in the world: heavy bunker oil

Kåre Press-Kristensen, senior adviser at the Green Transition Denmark 

"It might look fine above the water surface - because with a scrubber, the ships don't send nearly as many harmful particles and gases out through the chimney. In return, the environmentally hazardous substances are dumped directly into the water. So you have not solved a pollution problem, but simply moved it somewhere else - to the sea," he says and continues: 

"Here we have done nature in the sea a huge disservice. We should never have done that.” 

Birds caught in oil spill 

Another good reason to get rid of heavy bunker oil is to avoid the severe damage to nature when a ship runs aground, experiences a leak or intentionally washes their oil tanks. Most people have seen pictures or videos of birds and fish smeared in black oil. The heavy bunker oil breaks down very slowly and washes up on beaches, where birds and other animals are trapped and perish. If the ship instead leaks light bunker oil, it is diluted faster and does not cause as much damage to the ecosystems.  

“Almost every day there are shipwrecks somewhere on the planet. And sometimes it leads to serious oil spills, also here at home. At the same time, there are quite a few sailors of the old school who still manage to wash their oil tanks in the sea, even though it is illegal. The defense flies around and monitors the sea areas to make sure that doesn't happen. But far too many still see the sea as a landfill," says Kåre Press-Kristensen.  

Another challenge is that, regardless of whether ships sail on light or heavy bunker oil, they emit large amounts of nitrogen oxides (NOx), which can come into contact with rain or surface water and end up in the sea as nitrate. Nitrate helps to increase algae growth and thus cause oxygen depletion in the sea. So even though agriculture is the biggest emitter of nutrients (see page 4), the ships contribute to the problem, also in summer, when the emissions from the fields are otherwise smaller.  

"If you take all the cars, power plants and other sources on Danish soil that emit nitrogen oxides (NOx), shipping in the waters around Denmark emits well over twice as much. And while pollution from land-based sources will decrease drastically over the next ten years – partly due to stricter EU requirements for nuclear power plants and cars, partly due to more electric cars – NOx pollution from shipping will increase. This is because there is currently an increase in the number of ships at sea and their speed. We have introduced ambitious rules that regulate NOx emissions from 2021. But they only apply to new ships. So all the existing ones can continue to pollute. Otherwise, the solution here is quite simple. All that is needed is a catalyst on the ships' chimneys that can remove the harmful particles," he says.  

It must be trouble  

According to Kåre Press-Kristensen, the best way to get rid of heavy bunker oil is to go for a ban on the discharge of flue gas water. In the first instance, it is about getting a ban in Danish territorial waters. That is in the area approx. 12 nautical miles (22 km) from the coast. The Danish state can decide that itself, and it will mean that ships cannot dump flue gas water near coasts and inside our harbours. Countries like China and Malaysia have made such bans.  

"On the one hand, a ban will not mean a world, because most large cargo ships sail in the international parts of our waters. On the other hand, it will send a clear signal that we do not want ships on heavy bunker oil. And the cruise ships will not be able to sail into e.g. Copenhagen or Aarhus Harbor and discharge a huge amount of flue gas water when they are docked and have to generate electricity for cabins, pools and casinos. If we can then get many other countries to do the same, e.g. in the EU, then it starts to be a hassle to be a cargo ship or a cruise ship with scrubbers on a trip in Europe," he says, adding that some European countries have already banned flue gas emissions in e.g. harbours, rivers or fjords.  

A global ban on the discharge of scrubber water is the optimal goal that will once and for all force shipping to drop the heavy bunker oil. But the resistance is high and the workflows in IMO are slow. Meanwhile, the number of ships is increasing because more and more goods have to be transported. This increases the number of ships with scrubbers and the discharge of toxins into the sea. The Danish sea areas are particularly sensitive, as they are small, enclosed and shallow. There is no great dilution here, and the substances accumulate much more in fish and sediments than they do in the large open oceans. 

"So Denmark must take responsibility and ban it at home, just as many other states have already done. After all, it should be the case that in the future we can swim in the Danish harbors and that we can fish and collect mussels and eat them. So we must put an end to the pollution and thereby force the ships to switch to cleaner fuels," says Kåre Press-Kristensen.   

This article is from the theme 'Green hope for the blue ocean' in our summer issue of The magazine Grøn Omstilling. You can become a member or subscriber, and we will send the magazine to you by post.