The Arctic has warmed nearly four times faster than the rest of the world over the past 40 years, a new study finds, raising new concerns about the underestimation of climate models at the poles, whose warming has a major impact on sea-level rise.

The study, published in the journal Communications Earth & Environment of the Nature, significantly increases the rate of warming in the region around the North Pole.

In 2019, the UN’s Intergovernmental Panel on Climate Change (IPCC) estimated that the Arctic is warming “more than twice the global average” as a result of some process in the region.

This phenomenon, called “Arctic intensification,” occurs when sea ice and snow that naturally reflect the sun’s heat melt into seawater that absorbs more solar radiation and warms.

Although scientists have long agreed on the accelerated warming of the Arctic, their estimates of this phenomenon still differ depending on the period they choose to study or the more or less broad definition of the Arctic geographic zone.

In the new study, researchers from Norway and Finland analyzed four sets of temperature data collected above the Arctic Circle by satellites since 1979, the year satellite data first became available.

They concluded that the Arctic is warming by an average of 0.75 degrees per decade, almost four times faster than the rest of the planet.

Due to greenhouse gases produced by human activities, mainly fossil fuels, the planet has already gained almost 1.2 degrees C since the pre-industrial era.

“The scientific literature suggests that the Arctic is warming about twice as fast as the rest of the planet, so I was surprised that our finding was much higher than the usual figure,” said Antti Lipponen, a member of the Finnish Meteorological Institute and co-author of the study.

However, the study found significant local variations in the rate of warming within the Arctic Circle. For example, the Eurasian sector of the Arctic Ocean, near Norway’s Svalbard archipelago and Russia’s Novaya Zemlya, is warming by 1.25 degrees per decade, about seven times faster than the rest of the world.

Melting ice sheets are the main driver of sea level rise, outpacing melting glaciers and ocean expansion due to warming water.

Sea levels have risen by 20 cm since 1900. However, the rate of this increase has nearly tripled since 1990, and depending on the scenarios, the oceans could gain between 40 and 85 cm by the end of the century.

The Greenland ice sheet, which may be approaching a melting “tipping point” according to recent research, contains enough frozen water to raise the level of Earth’s oceans by up to six meters. (Source: AFP)

Photo: Dreamstime.com