The Arctic will lose all its ice for the first time in the next two decades

The ice covering the Arctic reaches its minimum each September, thanks to the warm summer heat. Since the end of the century, this minimum has been more and more pronounced. According to NASA data, based on several of their satellites, the extent of the polar cap has been shrinking at a rate of 12.6% every decade since 1980. But climate variability itself makes it difficult to know when the entire Arctic Ocean will be water. Now, a study supported by observations from NASA and ESA satellites and a sophisticated climate model predicts that, between 2030 and 2050, the first ice-free September will arrive. And if greenhouse gas (GHG) emissions are not reduced, by 2100 the Arctic region will be ice-free for almost half a year.

Until the beginning of the century, trying to navigate the Northwest Passage (the one that connects the Atlantic Ocean with the Pacific Ocean through northern Canada) was an adventure restricted to summer and on board an icebreaker ship. The situation was somewhat better in the Northeast Passage (through the far north of Russia), where the ships could coast a couple of months out of the year. Today, both routes are relatively safe in summer, so much so that there are beginning to be tourist cruises on old icebreakers. But the Arctic Ocean resists circumnavigation: Even today, the Wandel Sea, the portion that connects to northern Greenland, remains frozen year-round. But according to a new study published today in the scientific journal Nature Communicationsships could even reach this area and the very center of the North Pole in a few years.

“We see that the Arctic Ocean will be free of ice in summer between 2030 and 2050 in all the emission scenarios that we consider,” says the researcher at the Climate Change Research Laboratory of the University of Pohang (South Korea) in an email. Seung-Ki Min, co-author of the study. It must be taken into account that the future emission scenarios correspond to the objective of not exceeding the 2º of extra warming that was approved in the 2015 Paris Agreement. This is the most optimistic scenario, so it seems that the thaw is inevitable . But it also means that, as Min says, “we can avoid a summer ice-free Arctic if we can cut GHG emissions more aggressively, like the 1.5º warming alternative path.” The problem is that, according to various studies, this limit for the increase in global average temperature has already been exceeded regionally and could be exceeded globally in less than five years.

The work led by Min is based on the evolution of Arctic ice followed by various satellites, with data dating back to 1979 and up to 2019. One of the contributions of these 40 years of data is that, at least since the end of the decade From the 1990s, the polar cap loses ice every month, not just in summer. Since the end of the last ice age, the annual cycle of the Arctic followed the same pattern: the extent of the Arctic sea ice reached its maximum extent between March and April, to decrease in the following months, until its minimum between September and October, when it returned to start cycle. But all the data indicates that the frozen portion of the ocean is getting smaller every new March, so there is also melting even in the coldest years, even if it is in the margins.

“Previous work had looked at melting throughout the year, but our study confirms that the decline in Arctic sea ice in all months is mainly due to increases in human-induced greenhouse gases,” Min said. It is the other great contribution of this work, the confirmation of human responsibility. The Sun, its rays and heat, are what melt the Arctic sea ice. But there are agents that can mitigate or aggravate the action of solar radiation. The natural atmospheric agent that most affects are volcanic emissions. The particles act as a sunshade, cooling. Other particles, these caused by industry, cars and human heating, also have their role. What they have seen is that neither natural nor artificial particles are being decisive: their cooling capacity cannot counteract the warming caused by carbon dioxide (CO₂) and the rest of the GHG.

“Almost all of the melting that we have observed in recent decades has been caused by us humans”

Dirk Notz, Deputy Director of the Institute for Oceanography at the University of Hamburg

The deputy director of the Institute of Oceanography at the University of Hamburg, Dirk Notz, is one of the leading experts on Arctic ice dynamics. In fact, he was one of the main authors of the sixth and last report of the Intergovernmental Panel on Climate Change (IPCC) and co-author of the section dedicated to the ocean, the cryosphere and the sea level. Notz is also a co-author of this new study on Arctic melting and insists on human responsibility: “We quantified the human impact on the massive loss of sea ice observed in the Arctic by up to 90%. This means that almost all of the melting that we have observed in recent decades has been caused by us humans.”

The authors of the work used the latest system to model the evolution of the climate, known as CIMP6, capable of running several climate models at the same time, with a huge amount of data and requiring great computing power. To validate their results about the future, they compared those obtained by CIMP6 over the last 40 years and compared them with the real ones recorded by the satellites. “We saw that under all considered future scenarios, including the most optimistic scenario with substantial reductions in greenhouse gas emissions, the Arctic will be ice-free for the first time in September before 2050. This means that it is already too late to continue to protect the Arctic summer sea ice as a landscape and as a habitat: it will be the first major component of our climate system that we will lose due to our emissions.”

Although going beyond 2050 introduces more uncertainty, things will only get worse as the century progresses. The study predicts that, by 2100 and in the worst of the expected climate scenarios (in which GHGs are not reduced and the current rate of emissions is maintained), the Arctic would be without ice between May and October. The consequences of half a year without an Arctic ice pack would be far-reaching.

Despite what it may seem, the melting ice will not lead to a rise in sea level. Unlike the land ice accumulated in Greenland or Antarctica, the Arctic ice is already in the water, so nothing to worry about here. But so many months without ice will accelerate climate change: frozen water has the largest albedo effect in nature after snow. That turns the North Pole into a giant mirror that reflects much of the solar radiation, cooling the region. But, thawed, a sea enriched by oxygen from fresh water darkens, absorbing more of the sun’s energy. So the melting ice caused by global warming increases global warming.

The environmental consequences have already been observed since the beginning of the century. Many marine mammals need a minimum amount of ice to breed and rest (such as seals and elephant seals) or to hunt, such as arctic foxes and bears. In principle, an ice-free Arctic Ocean for half the year could be good for the large marine mammals, the whales. But after the thaw, humans will arrive. Shipping companies, mining companies, fishing boats, tourist cruises… The growing thaw is causing a series of geopolitical movements that could reconfigure a large part of the world order.

“An ice-free Arctic Ocean means that competition for resources and shipping via what China calls the Polar Silk Road could become a reality sooner than expected.”

Kristina Spohr, Professor of International History at the London School of Economics (United Kingdom)

“An ice-free Arctic Ocean means that competition for resources (fishing, oil and gas exploration) and shipping along what China calls the Polar Silk Road could become a reality sooner than expected,” says Professor of International History at the London School of Economics (United Kingdom) Kristina Spohr. From Berlin, where he was speaking on a panel on Russia, the war in Ukraine and the Arctic, Spohr believes that “there will be more tension between what is considered international and national open waters: international waters must be governed in a new way (fishing, maritime transport , exploration from the seabed); but national waters and ports will pose security concerns and therefore we will see more militarization, but it will also attract non-Arctic players such as investors in ports and other infrastructure and mining resources (China, but also Japan, Singapore, South East Asia, India and European countries).

For this expert in geopolitics, “the melting of the Arctic and the thawing of the world order, due to climate change, the war in Ukraine and tectonic changes in the international balance of power as China and Russia push for a subsequent world order to that of the West and a multipolarity that exceeds the rules imposed after the fall of the Wall [de Berlín], carries risks for the indigenous peoples of the Arctic, for the ecology, the regional flora and fauna and the situation of the region in general”. A region that, as Spohr recalls, “since the late 1980s has been considered a zone of exceptional peace”, protected by ice.

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