Arctic warming is happening faster than described, analysis shows

Publié le Mis à jour le

Icebergs float along the eastern coast of Greenland near Kulusuk in August 2019. Over the past four decades, the Arctic has been heating up four times faster than the global average, not the two to three times that has commonly been reported. | AFP-JIJI

The rapid warming of the Arctic, a definitive sign of climate change, is occurring even faster than previously described, researchers in Finland said Thursday.

Over the past four decades, the region has been heating up four times faster than the global average, not the two to three times that has commonly been reported. And some parts of the region, notably the Barents Sea north of Norway and Russia, are warming up to seven times faster, they said.

One result of rapid Arctic warming is faster melting of the Greenland ice sheet, which adds to sea-level rise. But the impacts extend far beyond the Arctic, reaching down to influence weather such as extreme rainfall and heat waves in North America and elsewhere. By altering the temperature difference between the North Pole and the equator, the warming Arctic appears to have affected storm tracks and wind speed in North America.

Manvendra Dubey, an atmospheric scientist at Los Alamos National Laboratory, in New Mexico, and an author of an earlier study with similar findings, said the faster rate of warming of the Arctic was worrisome, and points to the need to closely monitor the region. “One has to measure it much better, and all the time, because we are at the precipice of many tipping points,” like the complete loss of Arctic sea ice in summers, he said.

The two studies serve as a sharp reminder that humans continue to burn fossil fuels and pump greenhouse gases into the atmosphere at rates that are dangerously heating the planet and unleashing extreme weather.

Just weeks after a deadly heat wave clamped down on European capitals, shattering records in Britain, extreme temperatures are again engulfing western Europe this week. The heaviest rainfall in decades inundated Seoul, South Korea, killing at least nine and damaging nearly 3,000 structures. And the McKinney wildfire continues to rage in Northern California, destroying 60,000 acres, killing four people and triggering a mass fish kill.

If the rate of warming in the Arctic continues to speed up, the influence on weather could worsen, one of the researchers said. And projections of future climate impacts might need to be adjusted, said Mika Rantanen, a researcher at the Finnish Meteorological Institute in Helsinki.

 

Ice in the Northwest Passage near the CCGS Amundsen, a Canadian research ice-breaker navigating in the Canadian High Arctic, in September 2015. | AFP-JIJI
Ice in the Northwest Passage near the CCGS Amundsen, a Canadian research ice-breaker navigating in the Canadian High Arctic, in September 2015.
| AFP-JIJI

Even as the U.S. Congress is on the cusp of passing historic climate legislation, the country is still far from its goal to stop adding carbon dioxide to the atmosphere by 2050. That’s the target all major economies must meet, scientists say, for the planet to constrain average global temperature rise to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial levels. Beyond that threshold, the likelihood increases significantly of catastrophic droughts, floods, wildfires and heat waves. The planet has already warmed an average of about 1.1 C.

Although scientists have long known that average temperatures in the Arctic are increasing faster than the rest of the planet, the rate has been a source of confusion. Studies and news accounts have estimated it is two to three times faster than the global average.

Rantanen said he and his colleagues decided to look at the issue in the summer of 2020, when intense heat waves in the Siberian Arctic drew a lot of attention.

“We were frustrated by the fact that there’s this saying that the Arctic is warming twice as fast as the globe,” he said. “But when you look at the data, you can easily see that it is close to four.”

Their study was published Thursday in the journal Communications Earth and Environment,

(source: japantimes.co.jp)

 

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