Sustainable Arctic warming pushes the area of "unexplored territory" and is increasingly affecting the continental United States, scientists said on Tuesday.
"We see this continuing increase in heat penetrating the entire arctic system," said Emily Osbourne, an employee of the National Oceanic and Atmospheric Administration, who presented the agency's annual assessment of the state of the region. "
The Arctic has been warmer over the past five years than at any time since the recordings began in 1900, the report said, and the area is warming at a double pace like the rest of the planet.
Osborne, the lead editor of the report and head of the NOAA Arctic Research Program, said the Arctic is undergoing its "unprecedented transition to human history."
In 2018, "the warming temperatures of the air and oceans continue to lead to widespread long-term changes in the polar region, pushing the Arctic on uncharted territory," she said at a meeting of the American Geophysical Union in Washington.
The new edition of the report does not represent a radical break with past contributions but shows that the problems posed by climate change are increasing. Arctic air temperatures in 2018 will be the second-highest heat ever recorded, the report says, after 2016 only.
Susan M. Natalie, an Arctic scientist at Woods Hole Research Center in Massachusetts who did not participate in the study, said the report was another warning that would not happen. "Every time you see a report, things get worse and we still do nothing," she said. "There is added support that these changes happen that they are being observed."
The warmer air in the Arctic causes the stream to become "slow and unusually wavy," the researchers said. There are possible connections with extreme weather phenomena elsewhere in the world, including heavy storms in the last winter in the United States and bitter cold magic in Europe known as the Beast of the East.
The energy stream typically acts as a kind of atmospheric rotating lasso that surrounds and contains the cold air near the pole; the weaker, colder stream of jets can allow Arctic blasts to travel south in the winter and may interrupt weather systems in the summer, among others.
"On the eastern coast of the United States where the other part of the wave collapses," Osborne said, "you have these Arctic air temperatures that flow into the lower latitudes and cause these crazy winter storms.
Rapid warming in the upper part of the north, known as Arctic reinforcement, is linked to many factors, including the simple fact that snow and ice reflect a lot of sunlight, while the open-air water, which is darker, absorbs more heat. As the sea ice melts, less ice and more open water create a "feedback" to more flamboyant, resulting in gradually less ice and more open water.
And as Arctic waters become more free from ice, there are trade and geopolitical consequences: New shipping routes can be found, and rivalry with other countries, including Russia, is growing.
Some of the research results provided by 81 scientists from 12 countries include:
– In winter, the maximum area of sea ice in the region in March this year was the second lower than 39-year history.
– The ice, which lasts year after year, forming thick layers, disappears from the Arctic. This is important because very old ice has a tendency to resist melting; without this, the melting accelerates. Old ice accounts for less than 1% of the Arctic ice pack this year, down 95% over the past 33 years.
Donald K. Perovic, Dartmouth's marine ice expert, who contributed to the report, said the "big story" for this year's ice is in the Bering Sea, west of Alaska, where sea ice has reached a record low for almost the whole winter. In two weeks in February, usually when the sea ice grows, the Bering Sea has lost an area of Idaho-sized ice, Perovic said.
– The lack of ice and the accumulation of heat coincide with the rapid growth of algal species in the Arctic Ocean, linked to the harmful blooms that can poison the marine life and the people who eat the contaminated seafood. North Algae Shift "means that the Arctic is already vulnerable to introducing species into local communities and ecosystems that have never been exposed to this phenomenon," the report said.
– selenium and caribou have declined by 56% over the past two decades, with a fall of 2.1 million from 4.7 million. Scientists monitoring 22 herds found that two of them were at peak rates without dips, but five populations declined by more than 90% "and showed no signs of recovery."
– Small parts of oceanic plastic that can be swallowed by marine life are multiplying in the upper part of the planet. "Concentrations in the remote Arctic Ocean are higher than all other ocean basins in the world," the report said. Microplastics also appear in the Arctic ice. Scientists have found samples of cellulose acetate used in the manufacture of cigarette filters and plastic particles used in bottle caps and packaging material.
"The report's map continues to document the rapid discovery of the Arctic," said Rafe Pomerantes, chairman of Arctic 21, a network of organizations targeting the training of politicians and others on Arctic climate change. "Signs of decline are so strong, and the consequences are so great that they require much more urgent than all governments to cut emissions."