Summer melt season shrinks Arctic sea ice to second-lowest level in satellite record

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In the spring of 2004, freelance adventurer Ben Saunders, then just 26 years old, had to give up his attempt to make a solo trip across the North Pole from Cape Artichevsky in Siberia to Canada. He set out on skis March 5 and reached the pole on May 11. But 72 days after starting out, he had to be rescued about 30 miles from Canada because open water blocked his way. He had trekked 599 miles, often without mittens or hat, with temperatures as high as 60 degrees Fahrenheit compared with 2001 when it had averaged 33 degrees F. “The weather this year was the warmest since they began keeping records,” he told a reporter at the Ottawa Citizen before flying back to his U.K. home.

At the time, and for many years afterward, a number of climate science deniers asserted that ice in the Arctic Ocean was not melting more than in the past, but actually expanding. Last week, scientists at the National Snow and Ice Data Center based at my alma mater at the University of Colorado in Boulder announced that the extent of ice in the Arctic at the end of the summer melt season in 2020 is the second lowest in the satellite record, 2012 still being lowest. The 40-year trend, though not a straight line, is continuing its downward path and will someday soon result in ice-free summers in the Arctic Ocean, though predictions for that range from a few years to mid-century. The impacts for species dependent on the ice, for shipping, for weather around the planet, and for the people who live in the circumpolar world will be immense.

The NSIDC scientists wrote:

This year’s minimum set on September 15 was 350,000 square kilometers (135,000 square miles) above the record minimum extent in the satellite era, which occurred on September 17, 2012 (Figure 2a). It is also 2.51 million square kilometers (969,000 square miles) below the 1981 to 2010 average minimum extent, which is equivalent in size to roughly the states of Alaska, Texas, and Montana combined, or Greenland and Finland combined.

NSIDC Director Mark Serreze told Andrew Freeman at The Washington Post that people should view this as another warning. “We knew this would happen. … We knew this was coming, and here it is. … Maybe you should start listening to the scientists,” he said. What we’re seeing, is “a fundamentally different Arctic. I think the ramifications are extreme.”

Over the past 42 years, the extent of the end-of-summer ice visible on the surface has fallen by 31%. But, just as with icebergs, the bulk of the sea ice floats below the surface and, compared with the 1980s, the volume of ice in September has shrunk by 70%.

In 1985, according to a report from the National Oceanic and Atmospheric Administration, 16% of the Arctic Ocean was covered by the very oldest ice—more than 4 years old—at the height of winter. Now only about 1% is. The youngest ice, first-year ice, made up 55% of the sea ice in the 1980s, but that has now risen to 77%. The rest is just 2 or 3 years old. As sea ice becomes younger, the near-term prospect of ice-free summers grows. Chris Mooney wrote about this in detail two years ago.

As more ice melts, less sunlight is reflected back into outer space and more heat is absorbed by the ocean. Warmer water means more melting and more open water to absorb more heat and …. more melting.

Scientists observing the Arctic this year found much of the ice had turned to slush by late summer. Natalie Thomas and Cassandra Garrison reported two weeks ago:

From the deck of a research ship under a bright, clear sky, “ice pilot” Paul Ruzycki mused over how quickly the region was changing since he began helping ships spot and navigate between icebergs in 1996.

“Not so long ago, I heard that we had 100 years before the Arctic would be ice free in the summer,” he said. “Then I heard 75 years, 25 years, and just recently I heard 15 years. It’s accelerating.”

At the Climate News Network, Tim Radford writes that scientists believe the polar ocean is getting hotter at a rate faster than even the worst-case climate scenario predictions:

Such dramatic rises in Arctic temperatures have been recorded before, but only during the last Ice Age. Evidence from the Greenland ice cores suggests that temperatures rose by 10°C or even 12°C, over a period of between 40 years and a century, between 120,000 years and 11,000 years ago.

“We have been clearly underestimating the rate of temperature increases in the atmosphere nearest to the sea level, which has ultimately caused sea ice to disappear faster than we had anticipated,” said Jens Hesselbjerg Christensen, a physicist at the University of Copenhagen in Denmark, one of 16 scientists who report in the journal Nature Climate Change on a new analysis of 40 years of data from the Arctic region.

That acceleration is reflected in event after event. The Milne ice shelf, the last intact ice shelf in the Canadian Arctic, has collapsed. A Siberian town saw the temperature hit a record 100 degrees F in June. “Zombie” fires that had smoldered beneath the ice across the Arctic in winter blazed to life when snow melted in the spring, releasing thousands of tons of greenhouse gases. A study shows Greenland lost 586 billion tons of ice last year, far above the decade-long average of 259 billion tons a year and exceeding the record set in 2012. In the 1990s, the average loss was 33 billion tons a year. Thawing permafrost is transforming the Arctic. The list goes on and on. 

If what happens in the Arctic stayed in the Arctic, the change going on at the top of the world right now would be troublesome only for the 4 million people living in places like the near-Arctic Siberian city of Yakutsk where buildings are literally tipping over because of melting permafrost and for the 400,000 indigenous Inuit circumpolar peoples who are seeing whole towns collapsing for the same reason. As we know all too well, however, what happens in the Arctic will have far-reaching effects. Melting permafrost, for instance, puts not only carbon dioxide in to the atmosphere but methane as well, which, over 20 years, is 86 times more potent a greenhouse gas than CO2.

The impact on Inuit is not a new occurrence. In 2002, the 1,200-page Arctic Climate Impact Assessment was released. Cited in the report was Sheila Watt-Cloutier, an inhabitant of Iqaluit in the Canadian Arctic where her ancestors have lived and fished for thousands of years. 

”Talk to hunters across the North and they will tell you the same story—the weather is increasingly unpredictable. The look and feel of the land is different. The sea-ice is changing. Hunters are having difficulty navigating and traveling safely. We have even lost experienced hunters through the ice in areas that, traditionally, were safe! Our Premier, Paul Okalik, lost his nephew when he was swept away by a torrent that used to be a small stream. the melting of our glaciers in summer is now such that it is dangerous for us to get to many of our traditional hunting and harvesting places.  … Inuit hunters and elders have for years reported changes to the environment that are now supported by American, British, and European computer models that conclude climate change is amplified in high latitudes.”

While indigenous people, people of color, and people of low income will suffer the worst impacts from the climate crisis, everyone alive will be affected at least somewhat by the Arctic temperature rise of 9 degrees Fahrenheit that scientists think will occur by mid-century, 15° F by 2100. That rise is baked in even if the world’s nations were to fulfill their pledges under the Paris climate accord. So far, the promised actions come nowhere close to what is needed to prevent the global temperature rise from exceeding 3.6 degrees Fahrenheit.