Earth's northern ice cap experienced a rapid shift in 2016, setting the stage for widespread changes in not just Arctic environments, but the entire northern hemisphere, editors and contributors to the 2016 Arctic Report Card said.
"We've seen a year in 2016 in the Arctic like we've never seen before," Jeremy Mathis, director of NOAA's Arctic Research Program, told reporters Tuesday at the American Geophysical Union conference in San Francisco.
"The report card this year clearly shows a stronger and more pronounced signal of persistent warming than in any previous year in our observational record," Mathis said.
Particularly dramatic was the late start to the annual autumn ice buildup, noted Marco Tedesco, with the Lamont-Doherty Earth Observatory at Columbia University in New York.
The report, which is based on observational evidence not computer models, shows air temperatures over Arctic lands were 3.5 degrees Fahrenheit warmer in 2016 - compared to 1981-to-2010 baseline measurements - and the warmest on record since observations began in 1900, Mathis said.
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For the past 11 years, those observations have been collected and published in an annual report.
"When we started you kind of had to listen closely because the Arctic was whispering change and now it's not whispering anymore. It's speaking change, it's shouting change," said Dartmouth College geophysicist Donald Perovich.
For example, in the 1980s the amount of ice covering Arctic seas every September was equivalent to the size of the continental United States, Perovich said.
This year, the equivalent of all the land east of the Mississippi River, plus all the states from Minnesota to Louisiana and all of North Dakota, were exposed.
"The changes are significant. The changes are real," Perovich said.
Issues posed by Arctic warming include food production and the survival of local communities, but the melt of ice sheets also opens new opportunities for commerce, such as commercial shipping routes, resource exploration and extraction and tourism, Mathis said.
"There will be new opportunities in the Arctic that allow us to grow commerce and support the economy, so it will be a tradeoff over the next few decades as the Arctic changes," Mathis said. "We just need to make sure that we are providing the information to the residents and to the stakeholders so that our responses are effective and as good as they can be."
The loss of ice triggers a cascade of secondary effects, such as additional absorption of heat from the sun since the dark ocean does not reflect light like white ice. Melted permafrost also releases greenhouse gases into the atmosphere that were previously locked in the frozen tundra.
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"What happens in the Arctic doesn't stay in the Arctic," Mathis said.
When asked about how the incoming Trump Administration might impact science funding for the collection of data and publication of the annual report, Mathis noted that the project is widely backed and not intended for any specific audience.
"This is the best possible science that we can do and the best possible information we can provide to the American people and to our leadership in the U.S. government and around the world.
"The Arctic Report Card provides us with an opportunity to explain the changes we are seeing in the Arctic and to put it into a context that people can understand," Mathis said. "We have every intention of continuing to publish the Arctic Report Card."
The Helheim/Kangerdlugssuaq region of Greenland on Sept. 11, 2016, shows the midmorning sun glinting of the Denmark Strait. Credit: NASA's IceBridge Survey/John Sonntag.
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