The Arctic winter has ended with more news that worries even scientists who are closely watching the effects of climate change.
The region experienced its warmest winter on record. Sea ice hit record lows at the time of year, new US weather data revealed on Tuesday.
"It's crazy, crazy," said Mark Serreze, director of the National Snow and Ice Data Center in Boulder, Colorado, who has been studying the Arctic since 1982. "These heat waves, I've never seen anything like it."
Experts say what is happening is unprecedented, part of a cycle fueled by global warming that likely played a role in the recent strong freezing storms in Europe and the northeastern United States.
The ground weather station closest to the North Pole, at the tip of Greenland, passed more than 60 hours above freezing in February. Before this year, scientists had seen the temperature there rise above freezing in February only twice before, and then very briefly. Record temperatures last month were closer to typical May, said Ruth Mottram, a climate scientist at the Danish Meteorological Institute.
Out of nearly three dozen different Arctic weather stations, 15 of them were at least 10F (5.6C) above normal during winter.
Arctic warming: scientists alarmed by "crazy" temperature increases
"The extended heat has really left us all reeling," Mottram said.
In February, Arctic sea ice covered 5.4 million square miles, about 62,000 square miles smaller than last year's all-time low, the ice data center reported, and was 521,000 square miles below the normal of 30 years.
Sea ice is frozen ocean water that, in contrast to icebergs and glaciers, forms, grows, and melts in the ocean. It's still growing, but "what we grow now is going to be something thin" that melts easily in the summer, Serreze said.
Something similar was observed in the open water Pacific in the normally icy Bering Sea, said data center lead scientist Walt Meier. Happening to be happening on opposite sides of the Arctic at the same time was unusual, he added.
"Climate change is the most important thing," Meier said.
Original article (in English)