The climate is changing rapidly, and scientists are genuinely concerned by some recently discovered signs. In the far north of Greenland, the Cape Morris Jesup weather site has had a record 61 hours of temperatures above freezing so far in 2018, linked to a rare retreat of sea ice in the dark arctic winter.
"It has never been so extreme," said Dr Ruth Mottram, a climate scientist at the Danish Meteorological Institute (DMI).
Reuters Newsagency reports that heat was entering the Arctic both from the Atlantic and through the Bering Strait, driving and with cold air to the south.
Around the entire Arctic region, temperatures are now around 20 degrees Celsius above normal, at -8.0 ° C, according to DMI calculations.
To the south, a strange snowstorm hit Rome and some Brussels mayors planned to detain the homeless overnight if they refused to take shelter in temperatures that would drop to -10 ° C next week.
Struck by winds from the east of Siberia, cities from Warsaw to Oslo were below -8.0 ° C.
As early as 1973, a study suggested that an ice-free Arctic Ocean could make regions even colder to the south.
That "warm Arctic, cold continent" (WAC # C) pattern is sometimes referred to as "wacc-y" or "crazy" among climate scientists.
"The weird weather continues with terrifying strength and persistence," tweeted Professor Lars Kaleschke, a professor at the University of Hamburg.
“The question is whether this weather will occur more frequently.
"This is just one event, so it is difficult to establish a causal relationship," he told Reuters.
Scientists say that a long-term reduction in sea ice in the Arctic Ocean, linked to global warming, exposes warmer water that releases more heat into the atmosphere.
That in turn may be altering the high altitude jet stream.
"The jet stream becomes more wavy, which means cooler air can penetrate further south and warmer air further north," said Nalan Koc, director of research at the Norwegian Polar Institute.
Arctic Ocean sea ice is at an all-time low by the end of February at 14.1 million square kilometers, according to the United States National Snow and Ice Data Center.
That's about a million less than normal, or about the size of Egypt.
Erik Solheim, the United Nations Environment Chief, said the rare climate fits a broader pattern driven by the build-up of greenhouse gases, mainly from the burning of fossil fuels from cars, factories and plants. Energy.
“What we once considered anomalies are becoming the new normal. Our climate is changing right in front of our eyes, and we only have a short period of time to prevent this from getting significantly worse, "he told Reuters.
Under the 2015 UN-sponsored Paris Agreement on climate change, nearly 200 nations agreed to limit a rise in temperatures to "well below" 2.0 ° C above pre-industrial times, while continuing to strive to limit it to 1.5 ° C.
"The risk of an ice-free Arctic in summer is around 50 percent or more" with warming between 1.5 ° C and 2.0 ° C, according to a leaked draft of a scientific report from a UN panel of scientists, Obtained by Reuters.
The World Meteorological Organization said the cooling in Europe was caused by a "sudden warming of the stratosphere" over the North Pole that led to a split in the polar vortex, a cold area of air over the Arctic that spilled southward.
A big problem in determining whether the Arctic heat is dependent on human activities or natural variations is the lack of measuring stations.
There are no thermometers at the North Pole, and satellite measurements date from the late 1970s.
In the Norwegian archipelago of Svalbard, temperatures were above freezing, with rain, and about 13.4 ° C above the long-term average.
"There were also recent winters with similar deviations," said Dr. Rasmus Benestad, senior scientist at the Norwegian Meteorological Institute.
US President Donald Trump, who plans to abandon the Paris Agreement, has often expressed doubts about the science of dominant global warming during cold spells, such as New Years in the eastern United States.
Dr Mottram at DMI said that Europe's winters had become less severe.
“It's not really that cold. It's just that our perceptions have changed since a normal winter. "
By David Twomey
Original article (in English)