Recent Arctic warming unprecedented
Each year for the past 12 years, an international team of scientists have issued a ‘report card’ on the Arctic climate system. The report amounts to a physical exam of the vast, rapidly changing region, including details on everything from surface air temperatures to sea ice melt and permafrost loss.
With each passing year, the report cards have become more dire, depicting a region that is moving into a totally new regime as sea ice melts, air temperatures warm, and the once permanently frozen ground gives way. The report is the product of 85 scientists from 12 different countries, mashable. com wrote.
The 2017 Arctic Report Card, released at the annual meeting of the American Geophysical Union in New Orleans, is no exception, with scientists warning that the magnitude and the pace of the 21st Century plunge in sea ice extent as well as the amount of ocean surface warming is unprecedented in at least the past 1,500 years.
High-resolution Arctic paleo-reconstructions, based on 45 different ‘proxy’ indicators, such as tree rings, sediment cores, and ancient air bubbles trapped in ice cores, permit scientists to trace sea ice extent back well before there were satellites monitoring the region.
“The Arctic shows no signs of returning to the reliably frozen state it was in just a few decades ago,” said Jeremy Mathis, who leads the Arctic program for the National Oceanic and Atmospheric Administration (NOAA).
“The Arctic is going through the most unprecedented transition in human history,” Mathis said.
He explained that everyone in the US and the rest of the Northern Hemisphere has a stake in what happens in the far north.
“We want every single American to know… these changes will impact all of our lives,” he added, citing climate refugees, extreme weather events, and higher food prices that have potential links to rapid Arctic climate change. Mathis said modeling studies increasingly show that there are links between sea ice loss in the Arctic, which changes the amount of heat and moisture in the air there, and extreme weather events that affect the US and Europe, though he cautioned this research is not yet definitive.
According to the report, the Arctic had its second-warmest year on record in 2017, with an average annual air temperatures of 2.9F° above the 1981 to 2010 average. Temperature data for the region dates back to 1900.
Sea ice extent, which peaks in late winter, didn’t have much of a recovery after summer melting. The winter ice maximum was the lowest on record since satellite measurements began in 1979, the report said.