Older Arctic sea ice is being replaced by thinner, younger ice. NOAA reports that multiyear ice accounts for just 21 percent of the ice cover in 2017. Credit: Thomas Newman/CICS-MD/NOAA
Climate scientists say the magnitude and rate of sea ice loss this century is unprecedented in 1,500 years and issue a warning on the impacts of a changing climate...
The Arctic experienced its second-warmest year on record in 2017, behind only 2016, and not even a cooler summer and fall could help the sea ice rebound, according to the latest Arctic Report Card.
"This year's observations confirm that the Arctic shows no signs of returning to the reliably frozen state that it was in just a decade ago," said Jeremy Mathis, director of the Arctic program at National Oceanic and Atmospheric Administration (NOAA), which publishes the annual scientific assessment.
"These changes will impact all of our lives," Mathis said. "They will mean living with more extreme weather events, paying higher food prices and dealing with the impacts of climate refugees."
The sea ice in the Arctic has been declining this century at rates not seen in at least 1,500 years, and the region continued to warm this year at about twice the global average, according to the report. Temperatures were 1.6° Celsius above the historical average from 1981-2010 despite a lack of an El Nino, which brings warmer air to the Arctic, and despite summer and fall temperatures more in line with historical averages.
Among the report's other findings:
- When the sea ice hit its maximum extent on March 7, it was the lowest in the satellite record, which goes back to 1979. When sea ice hit its minimum extent in September, it was the eighth lowest on record, thanks in part to the cooler summer temperatures.
- Thick, older sea ice continues to be replaced by thin, young ice. NOAA reported that multiyear ice accounts for just 21 percent of the ice cover, compared with 45 percent in 1985.
- Sea surface temperatures in the Barents and Chukchi seas in August were up to 4°C warmer than the 1982-2010 average.
- Permafrost temperatures in 2016 (the most recent set of complete observations) were among the highest on record.
The report card's findings were announced at the annual conference of the American Geophysical Union, an organization of more than 60,000 Earth and space scientists. The report card is peer reviewed, and was contributed to by 85 scientists from 12 countries.
When the Arctic sea ice hit its maximum extent on March 7, 2017, it was the lowest in the satellite record. Credit: Arctic Report Card
Timothy Gallaudet, a retired Navy admiral who is the acting NOAA administrator, told the audience of scientists that the findings were important for three main reasons. The first reason, he said, was that "unlike Las Vegas, what happens in the Arctic doesn't stay in the Arctic."
The next two reasons, he said, "directly relate to the priorities of this administration": national security and economic security.
"From a national security standpoint, this information is absolutely critical to allow our forces to maintain their advantage," Gallaudet said.
From an economic one, the changes in the Arctic bring challenges—like those faced by Alaskan communities threatened by coastal erosion—but also opportunity. "Our information will help inform both of those as we approach the changing Arctic," he said.
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