Jonathan Nakstrand, via AFP
The Arctic has warmed nearly four times faster than the rest of the world over the past 40 years.
Environment – The Arctic has warmed nearly four times faster than the rest of the world over the past 40 years. These conclusions from a new study raise concerns that climate models for the poles are underestimated. What poses a big problem while global warming has a huge impact on sea level rise.
The study published in the journal Earth and Environment Communications Collection temper nature, significantly increases the rate of warming in the area around the Arctic. In 2019, the United Nations Climate Panel (IPCC) estimated that the Arctic is warming “More than double the global average”, under the influence of a region-specific operation. This phenomenon is called “Arctic amplification”It occurs when sea ice and snow, which naturally reflect the sun’s heat, melt into seawater that absorbs more solar radiation and heats up.
4-7 times faster heating
Although scientists have long agreed to observe the acceleration of warming in the Arctic, their estimates of the phenomenon vary depending on the period they choose to study or determine the geographical region of the North Pole, in one form or another.
In the new study, the researchers, based in Norway and Finland, analyzed four sets of temperature data collected across the entire Arctic Circle by satellite since 1979, when satellite data first became available. They concluded that the Arctic has warmed at a rate of 0.75 degrees Celsius per decade, four times faster than the rest of the planet. The Earth has already gained about 1.2°C compared to the pre-industrial era, due to greenhouse gases from human activities, mainly from fossil fuels.
The team found that the most advanced climate models predicted a warming of the Arctic by about a third less than their data shows.“The scientific literature considers that the Arctic is warming at twice the rate of the rest of the planet, so I was surprised that our conclusion was much higher than the usual figure.”, explains to AFP Ante Libonen, a member of the Finnish Meteorological Institute and co-author of the study. This discrepancy, in their opinion, can be explained by the obsolescence of previous models of the Arctic climate, which are constantly being improved.
The study also found significant local differences in the rate of warming within the Arctic Circle. Par exemple, le secteur eurasien de l’océan Arctique, près de l’archipel norvégien de Svalbard et celui russe de Nouvelle-Zemble, s’est réchauffé de 1,25 °C par décennie, soit environ sept foisle plus vite que From the world.
Extreme warming in the Arctic, in addition to the serious impact on local populations and fauna, which depends on the persistence of sea ice for fishing, will also have global repercussions. “Climate change is man-made, and as the Arctic warms, glaciers will melt, which will affect global sea levels. Remember, Ante Lebonin? Something is happening in the Arctic and it will affect all of us.”
The melting of the ice sheet is the main driver of sea level rise, before glaciers melt and the ocean expands due to rising waters. Melting sea ice (ice in the oceans) does not raise sea levels.
According to the Intergovernmental Panel on Climate Change (IPCC), the sea level has risen by 20 cm since 1900. However, the rate of this rise has almost tripled since 1990, and depending on the scenarios, the oceans could increase from 40 to 85 cm by the end of the century .. the ice sheet in Greenland, which can approach “turning point” It melts, according to recent studies, and contains a quantity of icy water capable of raising the level of the Earth’s oceans by up to six meters.
And what about Antarctica?
Another concern for scientists concerns Antarctica. Sea ice in Antarctica also reached record levels last month, with its surface area the smallest for July in 44 years of satellite records, European Climate Change Service Copernicus alerted, confirming an alarming year.
Sea ice is ice that floats on the ocean. So its melting does not raise sea levels, but rather contributes indirectly to global warming, as the open oceans absorb more heat.
This was only fixed in July, the southern hemisphere winter, at an average of 15.3 million square kilometers, which is 1.1 million square kilometers less (-7%) than the average for that month between 1991 and 2020, according to Copernican scholars ( C3S) found. In February, at the end of the Australian summer, sea ice had shrunk to an all-time low, much to the consternation of scientists. It was 30% below the average for the three decades between 1981 and 2010. Since February, it has remained below the season averages, according to C3S. And already in June, it reached its historic low for the month.
The natural cycle of sea ice, in the Arctic as in Antarctica, is that it melts in summer and re-forms in winter. In the long term, thawing is rapid in Greenland and the Arctic. On the other hand, in Antarctica, sea ice presents many anomalies: first of all, it melts less quickly despite significant annual and regional differences, without understanding the exact causes. Plus, unlike this year when it was the smallest ever, in July 2021 it was larger than average.
As a reminder, 2022 is the year of the world’s climate records. July was one of the three most recorded months in the world, according to the World Meteorological Organization (WMO), a Geneva-based United Nations specialized agency.
See also on The HuffPost: Global Warming: At the Poles, Another Catastrophe That Goes Unnoticed