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We have underestimated the pace at which the Arctic is melting



Arctic

Credit: CC0 Public Domain

Arctic sea ice is melting faster than previously thought. Today’s climate models should not include the steep rise in temperatures that have occurred over the past 40 years. This, according to a new study by researchers at the University of Copenhagen and other institutions.

Temperatures in the Arctic Ocean between Canada, Russia and Europe are warming faster than climate models researchers have been able to predict.

Over the past 40 years, temperatures have risen by one degree every decade, and even more so over the Barus Sea and around Norway̵

7;s Svalbard archipelago, where they have risen by 1.5 degrees per decade throughout the period.

This is the conclusion of a new study published in Natural Climate Change.

“Our analysis of Arctic Ocean conditions demonstrates that we have been clearly underestimating the rate of temperature rise in the atmosphere closest to sea level, which has ultimately caused sea ice to disappear faster than we expected,” he explains. Jens Hesselbjerg Christensen, professor at the University of Copenhagen Niels Bohr Institutes (NBI) and one of the study researchers.

Together with his NBI colleagues and researchers from the Universities of Bergen and Oslo, the Danish Metrology Institute and the Australian National University, he compared current temperature changes in the Arctic with the climate fluctuations we know from, for example, Greenland during the era. of ice between 120,000 –11,000 years ago.

“The sudden rise in temperature that is now being experienced in the Arctic has only been observed during the last ice age. During that time, ice core analyzes revealed that temperatures over the Greenland Ice Sheet rose several times, between 10 and 12 degrees, over a 40- to 100-year period, “explains Jens Hesselbjerg Christensen.

He emphasizes that the importance of steep temperature rise should not be fully appreciated. And, that an increased concentration in the Arctic and reduced global warming are, in general, whiskers.

Climate models must take into account sudden changes

So far, climate models have predicted that Arctic temperatures will rise slowly and steadily. However, the researchers’ analysis shows that these changes are moving at a much faster pace than expected.

“We have looked at climate models analyzed and evaluated by the UN Climate Panel. Only those models based on the worst case scenario, with the highest carbon dioxide emissions, come close to what our temperature measurements show. over the last 40 years, from 1979 to the present, “says Jens Hesselbjerg Christensen.

In the future, it should focus more on the ability to simulate the impact of sudden Arctic climate change. Doing so will allow us to create better models that can accurately predict temperature rise:

“Changes are happening so fast during the summer months that sea ice is likely to disappear faster than most climate models have predicted. We must continue to closely monitor temperature changes and incorporate the right climate processes into these.” models, “says Jens Hesselbjerg Christensen. He concludes:

“Thus, the successful implementation of the necessary reductions in greenhouse gas emissions to meet the Paris Agreement is essential in order to ensure an Arctic filled with sea ice throughout the year.”


Highest temperature ever recorded in the Norwegian Arctic archipelago


More information:
Eystein Jansen et al. Past perspectives on the current era of sudden Arctic climate change, Natural Climate Change (2020). DOI: 10.1038 / s41558-020-0860-7

Provided by the Niels Bohr Institute



citation: New study warns: We have underestimated the pace at which the Arctic is melting (2020, August 10) taken August 10, 2020 by https://phys.org/news/2020-08-underestimated-pace-arctic.html

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