Arctic transforming into ‘dramatically different state’ due to climate change
The Arctic is warming significantly faster than the rest of the world — possibly up to 4 times faster — and this is propelling the region into a very different state than it was in just a few decades ago.
A new report provides an in-depth look at the rapid and dramatic shifts being experienced in the Arctic due to climate change.
For the 16th year, now, the U.S. National Oceanic and Atmospheric Administration (NOAA) has issued their annual Arctic Report Card. Penned by over a hundred scientists from a dozen countries around the world, the report presents a comprehensive look at how the impacts of global warming and climate change over the past year — from October 2020 through September 2021 — have affected one of the world's most vulnerable climate regions.
"This year's Arctic Report Card continues to show how the impacts of human-caused climate change are propelling the Arctic region into a dramatically different state than it was in just a few decades ago," NOAA Administrator Rick Spinrad stated in a NOAA press release on December 14. "The trends are alarming and undeniable. We face a decisive moment. We must take action to confront the climate crisis."
As stated in the report, the Arctic continues to warm significantly faster than the rest of the world — at least twice the global rate, although new research indicates it could be up to four times faster. In 2020, October to December set a new record as the warmest Oct-Dec period in the Arctic in over 120 years. Taking the entire year into account, it was the 7th warmest year for the Arctic Circle.
This map shows how warm the Arctic was, on average from October 2020 to September 2021, compared to the 1981-2020 average. The graph shows just how much faster the Arctic is warming compared to the globe. Credit: NOAA Climate.gov
This warmth had impacts on both snow cover across land and on sea ice coverage across the Arctic Ocean.
For the 15th year in a row, June snow cover extent for Arctic North America was below the long-term average. Similarly, in Arctic Europe, there has been below average June snow cover for 14 of the past 15 years. Across Arctic Eurasia, June 2021 had the 3rd lowest terrestrial snow cover on record. And still, snow extent isn't the only thing being impacted by Arctic warming. The duration of the 'snow-free period' — between when snow melts between February and July, and the onset of snow cover in August to January — is increasing in many regions.
"One of the big [headline statements] is that 2020 had the longest snow-free period across Eurasia that we've seen in the 22-year record," Lawrence Mudryk, a research scientist at Environment and Climate Change Canada, said in an interview with The Weather Network.
Mudryk and his colleagues, who wrote the snow cover section of the report, also found that 2020 had the second longest snow-free period for the entire Arctic.
These maps plot the changes in snow cover for the 2020-21 snow year. On the left, (a) shows the onset of snow cover (August to January), with red indicating late onset and blue early onset. On the right, (b) shows the start of spring melt (February to July), with red indicating early melt and blue late melt. The 'snow-free period' refers to the number of days between these two times — spring melt and snow onset. Credit: Mudryk, et al./NOAA Arctic Report Card
As Mudryk explained, with an earlier snow melt, the water released from the melting snow enters the ground sooner than it normally would. This means the soil has more time to dry out by the end of the warm season. If there is any kind of prolonged drought period after that, Mudryk said, there is a greater potential for wildfires.
For Arctic sea ice, the September 2020 minimum extent was the second lowest seen in the 42 years of record-keeping. At just 3.74 million square kilometres, this is less than half of what was present in September of 1980. The only year with a smaller extent was 2012. While the 2021 minimum extent was only 12th lowest on record, the report card emphasizes that it was still significantly lower than the long-term average. Also, all 15 of the lowest minimum extents have occurred in the last 15 years.
An even more important indicator of Arctic climate change than the summer sea ice minimum is the sea ice maximum at the end of spring. In March of 2021, we saw the 7th smallest maximum on record, and the 10 smallest extents have all occurred since 2005.
Additionally, both the volume and age of sea ice are excellent gauges for the health of the Arctic climate. The Arctic Report Card states that the April 2021 volume of post-winter Arctic sea ice, when the ice should be at its thickest, was the lowest since records began in 2010. Also, the amount of multiyear sea ice — which is vitally important to marine life — at the end of summer 2021 was the second-lowest since records began in 1985.
The age and thickness of sea ice is just as important as extent, or even more important, and the current age and thickness of ice across the Arctic Ocean is very different from what was seen in the mid-1980s. Credit: NOAA Climate.gov
While many of these findings have been reported on separately, with their own headlines, this Arctic Report Card brings all of this information together in one place, so that we may see how it all ties together.
"I think one thing the report does a really good job of showing is the interconnected nature of Arctic change," said Mudryk. "Essentially, warmer temperatures are driving a host of interconnected changes in the region — not only sea ice and snow, but follow-on changes that those changes in sea ice and snow also cause."
"Sea ice affects primary productivity in the ocean," Mudryk noted, referring to how ocean organisms convert carbon dioxide in the water into organic matter, which provides a basis for the entire ocean food web. "Snow can affect the thaw rate of permafrost and spring runoff conditions, which of course have further follow-on effects in the ecosystem. So, one thing the report does is it provides an integrated view, year by year, of how those are affecting one another."
"There's undeniable evidence at this point that the Arctic is fundamentally different than it was in a previous generation," Mudryk said. "Essentially, the extent to which we're able to mitigate global warming is going to determine how much further the Arctic will change from what it already has."
Thumbnail image courtesy Mario Tama/Getty Images
