Global warming Greenland: The land of ice really turns green

Greenland ice is disappearing and being replaced by vegetation: in the last 30 years, 1.6% of the surface has become green, which has also caused profound changes in the landscape and ecosystems. This is revealed in an updated vegetation map led by Michael Grimes of the University of Leeds and published in the journal Scientific reports.

The transformation, which is also a consequence of global warming, risks exposing parts of the land of ice that are real treasure troves thanks to the natural resources they contain. A fact that, from a geopolitical point of view, could change quite a few things in the short term, given the current status of Greenland, a country that is only partially independent as it is subject to the Danish crown. In the last political election, the environmental party representing the Inuit community won thanks to its commitment to protecting the environment, for example by opposing the transfer – as the previous government wanted to do – of the rights to use the mountain, rich in “rare earths”. ” to Chinese companies. Exploitation that would affect not only the territory, but also the culture and society of Greenland. This stance is not surprising: there has been talk of a possible Arctic Brexit in the past.

At 2.1 million square kilometers, Greenland is the world’s largest island and is almost entirely covered in ice, but the effects of global warming are rapidly changing the landscape. Between 2007 and 2012, the region experienced an increase in average temperature of 3 degrees compared to the temperature recorded between 1979 and 2000, which led to a reduction in glacier coverage of almost 29 thousand square km, an extension slightly larger than the whole of Sicily.

Melting that led to the development of new vast green areas that did not exist before and that led, via a feedback mechanism, to faster melting of adjacent frozen areas, as rocks and soil absorb the Sun’s heat more easily than ice reflects most of the Sun’s rays. In addition, the reduction of the ice cover involves the emission of methane molecules – a gas that further accentuates the warming of the atmosphere – that were until now trapped in the frozen ground, permafrost. Finally, Grimes points out, “the expansion of vegetation that occurs simultaneously with the retreat of the glacier and the ice sheet significantly changes the flow of sediments and nutrients to coastal waters.” “Important changes especially for indigenous populations – concluded the British researcher, whose traditional hunting and subsistence based on the stability of these sensitive ecosystems.”

The retreat of the Arctic sea ice is not only affecting Greenland, but also all the countries located in this quadrant, such as Russia and the United States, who see this scenario as an opportunity to gain new resources to exploit. This retreat appears to support the advance of boreal forests into high latitudes. This is also proven in this case by a study published in a journal Science, conducted by researchers from the University of Alaska Pacific. A team led by Roman J. Dial combined field observations and remotely acquired images of 19 sites spanning 22 degrees of longitude along the treeline of northern Alaska. In addition, the research team examined a meta-analysis of data collected from 60 other Arctic sites. Experts explain that temperature is the main determining factor in the separation of forested landscapes and tundra at high latitudes. For this reason, scientists predict that boreal forests will also expand into high latitudes and replace tundra due to rising temperatures in the Arctic.

These changes, the researchers point out, could negatively affect the presence of albedo, promote the release of carbon from the soil and increase the risk of fire. As part of the work, the team linked the advance of the boreal forest to the retreat of Arctic sea ice. According to the survey, a greater percentage of boreal forests have developed where the surrounding sea is rapidly losing its autumn ice cover. However, in areas adjacent to persistent sea ice, forest expansion appeared more limited.

These results, the researchers comment, show that warmer temperatures and deeper snow cover through increased precipitation from the open water of the Arctic Ocean provide enriched soil nutrients and security for plants. These factors may drive forest advances through increased growth and survival of individual trees, promoting the replacement of arctic tundra by boreal forest. “Despite the rapid expansion of boreal forests – the authors write – it is unlikely that the northward advance will outpace the retreat of southern forests in the face of current climate change and other anthropogenic influences.” Although the causes of boreal forest expansion in the Arctic can be predicted, the full consequences of this and other biome changes remain unknown. Further investigation will therefore be necessary“.


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