Risk of large ice blocks breaking off in Greenland is increasing

Global climate change is accelerating the melting of the Greenland ice sheet at an alarming rate, with serious potential implications not only for the Arctic climate, but also for the global climate, including Europe.

According to a study led by researchers from the University of Barcelona (UB), episodes of extreme melting (periods in which large areas of snow and ice melt rapidly) have been approximately twice as frequent during the summers of recent decades compared to what happened in the summers of the period 1950-1990. The conclusions of the authors of the study have been amply supported by the terrifying collapse of the top of a mountain in Greenland last year and the colossal tsunami that this mass of ice and rock caused in the water of the fjord where it fell.

The research was led by Josep Bonsoms and Marc Oliva, professors and researchers at the Faculty of Geography and History of the UB; Juan Ignacio López-Moreno, researcher at the Pyrenean Institute of Ecology (IPE, dependent on the Spanish National Research Council (CSIC) in Spain; and Xavier Fettweis, from the University of Liège in Belgium.

The study analysed extreme melting episodes in Greenland between 1950 and 2022. The results show the figures for meltwater loss, which on average have reached around 300 gigatonnes per year (the equivalent of a volume of around 48 million Olympic swimming pools per year) between 1980 and 2010. In addition, approximately 40% of melting episodes have been extreme in recent decades. This figure increases to 50% in the coldest areas of the north and northwest of the island. “This loss of surface glacial melting must be added to that of other dynamic processes, such as the calving of icebergs directly into the sea and the flow of glaciers into the ocean, both accelerated by the increase in melting,” the UB researchers add.

Increased risk of large ice blocks breaking off

Ice melting phenomena have been directly linked to global warming, as recent studies have shown that the Arctic is warming at four times the global average due to increased greenhouse gases. The authors of the study explain that “increased melting is closely linked to episodes of extreme heat caused by more frequent, warm and humid anticyclonic air masses from more northern latitudes.” “These atmospheric patterns keep the air stagnant over Greenland during the summer, increase solar radiation and reduce the albedo (reflectance of sunlight) of snow and ice, which further accelerates warming and melting,” they add.

According to the UB researchers, the melting is occurring in higher areas of the ice cap, where between 1950 and 1990 no ice melting was observed. This situation has created cracks and other structural changes in the ice cap, and increases the risk of large blocks of ice breaking off into the ocean. “International climate reports anticipate a significant increase in temperatures in the polar regions, which would accelerate the trend we have observed in this study,” the researchers add.

Between 1980 and 2010, the equivalent of ice from approximately 48 million Olympic-sized swimming pools was lost each year. (Photo: Josep Bonsoms)

Future projections and impacts in Europe

The melting of Greenland ice has global consequences, as it is one of the major contributors to rising sea levels and also affects atmospheric circulation patterns. According to the researchers, these changes may also influence the climate of Europe. “These changes in temperature and precipitation patterns could impact socio-economic activities, ecosystems and may contribute to increasing climatic extremes in nearby regions of the North Atlantic,” the experts point out.

The researchers also warn that projected climate scenarios indicate an increase in these episodes: “This highlights the urgency of reducing greenhouse gas emissions to mitigate the impacts of climate change in the coming decades,” they conclude.

The study is titled “Rising Extreme Meltwater Trends in Greenland Ice Sheet (1950–2022): Surface Energy Balance and Large-Scale Circulation Changes.” It has been published in the academic journal Journal of Climate. (Source: Universitat de Barcelona)