The Arctic isn't quite the winter wonderland it used to be. The region is heating up twice as quickly as the rest of the planet, and it just experienced its warmest year on record, with average surface-air temperatures measuring "by far the highest since 1900," according to the 2016 Arctic Report Card. As an exclamation point for what's happening, a Christmas heat wave is expected to send North Pole temperatures soaring far above normal, approaching the 32-degree Fahrenheit (0 Celsius) melting point.
The Arctic has been on the front lines of climate change for a long time, losing its sea ice at a rate unseen in recorded history. But 2016 has been especially sweltering, and the year's last two months have raised concern among scientists that all this warmth could lead to record-low Arctic ice coverage in 2017. And because the white veneer of sea ice creates albedo, which helps reflect heat from the top of the world, more melting can kick off a feedback loop that triggers even more heat.
"Rarely have we seen the Arctic show a clearer, stronger or more pronounced signal of persistent warming and its cascading effects on the environment than this year," says Jeremy Mathis, director of the U.S. Arctic Research Program.
November and December normally kick off the season of sea-ice growth in the Arctic, but this November brought a brief retreat of sea ice unlike anything seen in nearly 40 years of satellite records, according to the National Snow and Ice Data Center, helping November 2016 set a record for lowest sea-ice extent since 1850. The area around the North Pole is typically 95 percent ice-covered by December, but this year's December coverage has only been about 80 percent. And according to a study released this month, it's "extremely unlikely" that these events aren't related to human-induced climate change.
"For all phases of this variability, a warm event like the one of this year would have been extremely unlikely in the climate of a century ago," the researchers write. "The probability was so small it is hard to estimate, but less than 0.1 percent per year. The model analyses show that the event would also have been extremely unlikely in a world without anthropogenic emissions of greenhouse gases and aerosols, attributing the cause of the change to human influences."
2015 was already the warmest year ever measured for the Earth overall, and 2016 is widely expected to break that planetary record. But the Arctic has been heating up at least twice as quickly as the global average, largely due to its feedback loop from lost sea ice. And while this spells trouble for entire Arctic ecosystems — including iconic wildlife like polar bears and reindeer — such dramatic changes in the Arctic will have ripple effects all around the world. As Mathis noted at a news conference this month, we're all closer to the North Pole than we might think, and now is a good time to heed what's happening up there.
"We need people to know and understand," he said, "the Arctic is going to have an impact on their lives no matter where they live."