Melting Arctic sea-ice could have dramatic effect on ocean circulation

By Thomas Nilsen, The Independent Barents Observer October 30, 2024
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It has been a record warm summer here at 80 degrees, north of Svalbard in the Arctic Ocean. Enhanced melting of sea-ice can significantly change ocean circulation, causing lower temperatures across northern Europe, a new study warns.

A photo for the next generation. Will kids growing up today be the last to experience ice-covered waters in the Arctic during summer periods? A lot is a stake for the future of planet earth. Photo: Thomas Nilsen

The photo above was taken by the Barents Observer mid-summer this year, a few hours sailing north of Svalbard into the Arctic Ocean. Here, the ice edge can move fast this time of the year depending on wind and currents.

The trend, however, is alarming. Arctic sea-ice is now not shrinking at a rate of 12% per decade compared with the average extent during the time of satellite recordings, from 1981 till today.

Minimum extent is September. After that, waters at the top of the planet starts freezing again. Minimums this year was estimated to 4,28 million square kilometres, slightly more than the 4,23 million sq. km. seen in 2023, but far below the 7,54 million sq. km. in 1981, according to the National Snow and Ice Data Centre with the University of Colorado Boulder.

To put that into perspective, it means the Arctic is losing sea-ice at a size similar to the country of Austria annually.

The map on the left shows Arctic sea-ice extent for September 11, 2024, at 4.28 million square kilometers. The orange line shows the 1981 to 2010 average extent for that day. The graph on the right shows Arctic sea-ice extent as of September 11, 2024, along with daily ice extent data for four previous years and the record low year. 2024 is shown in blue, 2023 in green, 2022 in orange, 2021 in brown, 2020 in magenta, and 2012 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. ;ap and illustration: National Snow and Ice Data Center

This summer was the third consecutive warmest summer on record at Svalbard. The one temperature record after the other were broken across the Arctic. In August, Longyearbyen for the first time ever measured above 20°C for the month.

Despite being the warmest summer ever, the sea-ice extent this September became seventh lowest in the more than 40-years of record, NASA reported. Extent, however, is one of three key sea ice metrics, the others be the volum of the ice and the age of the ice.

NASA’s data show that there are nearly no more 4-years old ice left in the Arctic. In the 80ties, the 4-years old ice constituted more than 30% of the sea ice. In 2024, about 60% of the ice was 0-1 years old. First year ice is much thinner, from a few centimetres and up to one meter, compared with multiple-year old ice which can be up to 3 metres thick. Thin ice naturally melts faster and might disappear fully during summer months.

The trend will eventually result in ice-free summer seasons, believed to be a reality by 2050.

A new study published in Nature Communications by scientists with the UiT – Arctic University of Norway, warns that warming climate in polar regions may significantly disrupt ocean circulation patterns. Looking at the distant past, the study document how growing inflows of freshwater from melting Arctic sea-ice into the Nordic Seas likely affected ocean circulation, causing temperatures to drop across northern Europe.

Our finding that enhanced melting of Arctic sea-ice likely resulted in significant cooling on northern Europe in the earth’s past is alarming, says Mohamed Ezat from the iC3 Polar Research Hub.

He notes that this is a reminder that the planet’s climate is a delicate balance, easily disrupted by changes in temperature and ice cover.

Scientists are now blowing the alarm bell, warning that circulation change in the North Atlantic would have devastating and irreversible impacts.

Waters between Norway and Greenland area a key area for oceanic heat transport. It influences weather patterns far beyond the west Nordic region.

The study looked at the warming period over 100,000 years ago when Arctic sea-ice melted and how that affected regional sea-surface temperatures and ocean circulation. With melting ice that time, the salinity and density of the water lead to changes in circulation patterns and heat distribution.

In November, the United Nations next climate conference, COP29, kicks off in Baku, the capital of Azerbaijan. This year’s focus for the world leaders is how to give more money to ramp up actions to reduce emissions of climate gases.

Phase out of fossile fuels and investing in renewable energy are the only solutions providing hope for the Arctic Ocean to remain ice-covered.

Right now, that goal seems like an unattainable dream.

Located in Kirkenes, Norway, just a few kilometres from the borders to Russia and Finland, the Barents Observer is dedicated to cross-border journalism in Scandinavia, Russia and the wider Arctic.

As a non-profit stock company that is fully owned by its reporters, its editorial decisions are free of regional, national or private-sector influence. It has been a partner to ABJ and its predecessors since 2016.