The National Oceanic and Atmospheric Administration on Tuesday released its annual Arctic Report Card, covering everything from rising temperatures on land and sea, to sea ice declines and its impact on Arctic ecosystems and the rest of the world.
Since the beginning of the 20th century, the report finds surface air temperatures in the Arctic have increased by 5.2 degrees Fahrenheit.
Jackie Richter-Menge is with the the Army Corps of Engineer’s Cold Regions Research and Engineering lab. She says half of that warming has happened in the last three decades.
“Between October 2014 and September 2015, the Arctic-wide annual average surface air temperature over the region was 1.3 degrees centigrade – or 2.3 degrees Fahrenheit – above the 1981-2010 baseline average,” Richter-Menge said.
That’s the highest annual average temperature in the observational record since it began in 1900.
Generally, Richter-Menge says air temperatures in all seasons were above average in the Arctic this year, with some reaching 5.4 degrees Fahrenheit above the baseline.
She says it was also an interesting year for sea ice, and the changes correlate strongly to the increasing air temperatures.
“In February 2015, the lowest-ever maximum ice extent in the satellite record – which begins in 1979 – occurred on the 25th of February,” Richter-Menge said. “This was 15 days earlier than average.”
And that record-low maximum was capped off with the 4th-lowest sea ice minimum on record in September 2015.
Along with declining sea ice, Richter-Menge says the composition of the sea ice has changed dramatically over the last few decades.
“In February and March, the oldest ice – defined as being greater than 4-years-old – made up 3 percent of the ice cover, while new first-year ice made up 70 percent of the ice pack,” Richter-Menge said. “Thirty years ago, in 1985, the composition of the ice cover was much different. Twenty percent of the ice pack was over 4-years-old and only 35 percent was classified as first-year ice.”
She says these observations confirm a trend toward a thinner, more vulnerable ice pack.
The ice pack isn’t the only thing made vulnerable by a warming climate. According to Kit Kovacs, with the Norwegian Polar Institute, marine mammals are greatly impacted – particularly walrus populations, which are hauling out on land rather than sea ice as they follow the retreating sea ice edge.
“This new haulout behavior is raising concerns about the well-being of females and their young that must now make a 180-kilometer long – that is 110 miles – feeding trips each direction from coastal haul-outs to areas of high prey abundance, rather than simply utilizing nearby ice edges as they did in the past,” she said.
Kovacs says fish populations are also changing in places like the Barents Sea – north of Scandinavia – where rising ocean temperatures are attracting fish species normally found in warmer waters, displacing cold-water, Arctic species.
Impacts are not limited to marine habitats. Martin Jeffries, an adviser for the U.S. Office of Naval Research, says the warming Arctic is resulting in lower snow pack coverage in May and June, and increasing water discharges from Arctic rivers.
“In 2014, the year for which we have the most-recent complete record, the combined discharge of the eight largest Arctic rivers was 10 percent greater than the average of 1980-1989,” Jeffries said.
The report says the changes recorded over the last few decades are clearly evident. And combined with projections of continued warming temperatures, we can expect to see further change throughout the Arctic in the future.