Why the Arctic route is heating up for global shipping

Going via the Northwest Passage can shorten the distance between East Asia and Western Europe by over 10,000 kilometres. Keystone / AP

Swiss researchers have studied how ships’ exhaust fumes affect cloud formation and melting ice in the Arctic, at a time when climate change and Middle East conflict are pushing vessels towards polar routes.

Julia Schmale, a professor at the Swiss Federal Institute of Technology Lausanne (EPFL), and PhD student Benjamin Heutte had initially been more interested in something else – natural aerosols in the Arctic. They wanted to find out more about how these particles are formed, how they move, and how they affect clouds and the climate.

To explore this, the team spent a year on a research vessel in the Arctic Ocean. But there was a problem: exhaust fumes – that is, aerosols which are not natural. Most of the time, with the wind coming from the same direction, their own ship’s exhaust gases were being blown directly over their measuring instruments.

They looked on the bright side. “We thought of it as a once-in-a-lifetime opportunity,” says Schmale, who describes it as “like a controlled experiment”. Air pollution in the Arctic is currently almost non-existent in summer, which meant their team could closely examine the effect of particulate matter and pollutants from a single ship on cloud formation.

Clouds play a key role in Arctic climate: they influence radiation by reflecting the sun’s rays back into the sky and the Earth’s infrared radiation back down to the ground.

But this doesn’t always happen in the same way. The higher the liquid water content in the cloud, the more it acts “like a blanket”, Schmale explains – meaning the Earth’s warm infrared radiation is sent back. This radiation transports heat even in icy conditions. And such clouds, which consist more of water droplets than small ice crystals, in turn influence the rate at which the ice melts.

Route planning: ships still have to weave their way through the ice, but it might become easier in future. Keystone / AP

When the cloud is situated above the ice, the impact of shipping-caused pollutants on the cloud within a radius of 100m leads to additional ice melt of around 1mm per day, according to the researchers’ preliminary estimates.

Conversely, when the cloud is over water, it has a cooling rather than a warming effect.

The study is a small piece of the larger puzzle of how clouds are formed – and how they affect the climate. As such, its significance is limited. But the overarching question is extremely relevant: do emissions from ships in the Arctic influence cloud formation and, consequently, ice melt?

Countries eye the Arctic route

According to the Alfred Wegener InstituteExternal link, a German polar and marine research centre, summer sea ice in the Arctic has been declining by 13% per decade since the 1990s. Satellite data even suggests the Arctic could experience its first ice-free summer as early as 2030External link.

As a result, passages once difficult to navigate are increasingly becoming transport routes for global shipping.

According to the Arctic CouncilExternal link, an intergovernmental forum of eight countries, shipping traffic in the Arctic has jumped by 40%External link in 12 years. Some countries are keen to explore the new sea routes and plan to make even greater use of them in future. The Arctic forms partExternal link of China’s Belt and Road Initiative, for example, and via its polar strategy, the country aims to position itself as a “near-Arctic state”External link by 2035. “China wants to become the leading nation in the Arctic,” says Anastasios Leonburg, a former captain and now a maritime risk adviser at Allianz Insurance in Germany.

To this end, China has long been active in the Arctic Council, where it has had observer status since 2013. It is also strengthening its partnerships with Arctic states. In Russia, for example, China is investing in a new LNG plant on the Yamal Peninsula.

For its part, Russia has announced plans to invest $400 billionExternal link (CHF333 billion) in infrastructure along the Arctic corridor, which runs along the Russian coast and links Europe with East Asia. Other countries also seem to be interested in the region as a future trade route: this August, South Korea sent a first merchant ship on a trial voyageExternal link through the Arctic.

A vast emptiness: but for how much longer? Keystone / AP

Geopolitical shifts steer ships towards the Arctic

Not all of this is down to melting ice and the Arctic becoming more accessible to commercial shipping during the summer months. It is also due to the current geopolitical situation, explains Leonburg. “What is happening in the straits of Hormuz and Bab al-Mandab is a catalyst for more ships sailing through the Arctic,” he says.

In September 2026, the Houthi militia captured the Yemeni city of Mocha near the Bab al-Mandab Strait – further fuelling fears that the militia could also block this bottleneck, which is crucial for global trade. Even before that, Houthi rebels had attacked ships linked to Saudi Arabia. “As a result, some ships are opting for the longer route round Africa,” says Leonburg.

By comparison, the Arctic corridor cuts the journey time from East Asia to Europe by half, Leonburg adds. This is what makes it so attractive to shipping companies: not only do they save time, they also use less fuel – and thus potentially save on taxes. Ships calling at European Union (EU) ports must purchase emission allowances for their CO₂ emissions. The International Maritime Organization (IMO) also agreed in April 2025 on a minimum tax on CO₂ emissions from global shipping. This is set to come into force in 2028 at the earliest.

By comparison, the Arctic corridor cuts the journey time from East Asia to Europe in half, Leonburg adds. This is what makes it so attractive to shipping firms: they save not just time but also fuel – and potentially taxes. Ships calling at European Union (EU) ports are obliged to purchase allowances for their CO₂ emissions. The International Maritime Organization (IMO) also agreed in April 2025 on a minimum tax on CO₂ emissions from global shipping, which is set to come into force in 2028 at the earliest.

And beyond that again, there is another decisive geopolitical factor in the race for the Arctic route: the war in Ukraine and Western sanctions against Russia. “Before 2022, it was largely European shipping companies that were testing this route,” says Leonburg. But now they face a problem: if their ships break down or need an icebreaker while at sea, they would have to get one from nearby Russia. This is not possible due to the Western sanctions – which have therefore potentially helped to create a competitive advantage for China.

>> As Arctic activity picks up, so does politics and diplomacy – what can Switzerland contribute?

Opinions differ on how shipping in the Arctic will develop in the future. Arild Moe from the Fridtjof Nansen Institute in Norway, who researches the Russian energy sector and shipping in the Arctic, says large sections of the Northern Sea Route are still covered in ice most of the year, and only remain commercially navigable for a few summer months. “All in all, the Arctic accounts for only a small proportion of global trade volumes,” he says.

In the longer term, the Arctic could conceivably become more important for shipping, Moe adds. “But any predictions on this remain speculative for now.” For example, the melting of the ice also raises security concerns for Russia by leaving its northern coast more exposed, he says.

For his part, Leonburg has a more optimistic outlook. “I don’t want to be too euphoric,” he says. “But shipping is a commercial sector. If companies see others increasingly sailing through the Arctic, they will try to do the same to remain competitive.”

Unclear impact on ice and climate

This does not bode well for air pollution in the Arctic – just as global shipping is harldly positive for the climate. However, it is uncertain whether more ship emissions in the Arctic will have a major impact on the melting of the polar ice. According to Christian Haas, head of the Sea Ice Physics Section at the Alfred Wegener Institute, the impact of shipping on ice melt is marginal.

Still, Haas commends the EPFL researchers for having addressed the question of cloud formation. “Clouds play a key role in ice melt due to their radiative effect,” he says. “At the same time, they are the greatest source of uncertainty.” Clouds are difficult to study: their properties are determined not only by their composition but also, for example, by their altitude – and, not least, they are constantly changing.

The prospect of increased commercial shipping in the Arctic does worry Haas, but more because of pollution and its consequences on ecosystems. “An oil spill, for example, would have far more severe consequences here than elsewhere, because microbial degradation occurs much more slowly due to the cold,” says Haas.

On the other hand, Haas notes, one could argue that overall CO2 emissions from shipping might decrease due to the shorter route, which in turn could be beneficial for the global climate. Whether this will happen or whether shipping volumes will continue to rise overall remains to be seen.

Similarly, many of the effects of climate change on the Arctic have yet to be researched. Since July, at least, Schmale from the EPFL has been on another eight-month research expedition in the Arctic winter – to collect samples and gain insights.

Edited by Benjamin von Wyl; Adapted from German by Patrick Julian Huwyler/dos

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