Climate change is accelerating the melting of ice in Greenland at an alarming rate, with serious implications not only for the Arctic, but also for the global climate, including Europe. According to a study led by researchers at the University of Barcelona, extreme melting episodes—periods when large areas of snow and ice melt rapidly—have been about twice as frequent during summers in recent decades compared to the period 1950–1990.

The paper, published in the Journal of Climate, shows that the last decade has seen peak years of extreme melting in Greenland. For example, during the summer of 2012, 610 gigatons of ice (the equivalent of 244 million Olympic-sized swimming pools) melted, and in 2019, 560 gigatons (224 million Olympic-sized swimming pools) melted.

The study was carried out by the Antarctica, Arctic and Alpine (ANTALP) research group of the UB’s Department of Geography. It was led by lecturers and researchers from the Faculty of Geography and History Josep Bonsoms and Marc Oliva, Juan Ignacio López-Moreno, a researcher at the Pyrenean Institute of Ecology (IPE-CSIC), and Xavier Fettweis, from the University of Liège (Belgium).

Development of melting ice in Greenland

The study has analyzed extreme melt episodes in Greenland between 1950 and 2022. The results show meltwater loss figures that, on average, have reached about 300 gigatons per year—the equivalent of a volume of about 48 million Olympic-sized swimming pools per year—between 1980 and 2010.

In addition, about 40% of the melting episodes have been extreme in recent decades. This figure rises to 50% in the coldest areas in the north and northwest of the island.

“This loss of surface glacial melt must be added to that of other dynamic processes, such as the detachment of icebergs directly into the sea and the flow of glaciers into the ocean, both of which are accelerated by increased melting,” add the UB researchers.

The risk of large ice blocks breaking off increases

Ice melting phenomena have been directly linked to global warming, with recent studies showing that the Arctic is warming at four times the global average rate due to increased greenhouse gases. The authors of the study explain that “increased melting is closely related to episodes of extreme warmth caused by more frequent, warmer and wetter anticyclonic air masses from more northern latitudes.”

“These atmospheric patterns keep the air over Greenland stagnant during the summer, increase solar radiation and reduce the albedo (sunlight reflectance) of snow and ice, which further accelerates warming and melting,” they add.

According to UB researchers, melting is occurring in higher areas of the ice cap, where no ice melt was previously observed between 1950 and 1990. This has created cracks and other structural changes in the ice sheet, 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.

Future predictions and impacts in Europe

Greenland’s melting ice has global consequences, as it is a major contributor to sea level rise and it also affects atmospheric circulation patterns. According to the researchers, these alterations may also influence Europe’s climate.

“These changes in temperature and precipitation patterns could impact on socio-economic activities, ecosystems and may contribute to increased climate extremes in nearby regions of the North Atlantic,” the experts note.

In addition, 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.

Researchers at University of Tsukuba have shown that the 1995 Kobe (Hyogo-ken Nanbu) earthquake, which struck southern Hyogo Prefecture, may have been triggered by deep underground flooding beneath Arima Hot Springs. By analyzing the stable isotope ratios of hydrogen and oxygen as well as chloride ions in Arima hot spring water over several decades, the researchers have uncovered a likely connection between the earthquake and water originating from the subducting Philippine Sea Plate.

Hot springs frequently contain water that originates from rocks within the Earth’s crust. This can be confirmed through isotopic analysis. Arima Hot Springs, located in Kobe, Hyogo Prefecture, Japan, exhibit unique characteristics, including salinity that is more than twice that of seawater, indicating that their water likely originates from the Philippine Sea Plate. However, direct evidence supporting this connection is lacking.

In a study appearing in Communications Earth & Environment, researchers confirmed that the isotopic ratios of plate-derived water beneath Arima Hot Springs, as predicted by a numerical model, agreed with those of nonmeteoric water components found in the actual spring water. Additionally, they observed that the proportion of plate-derived water decreased exponentially after the development of deep well drilling in the 1940s but saw a temporary increase around 1995.

Notably, before the 1995 Kobe (Hyogo-ken Nanbu) earthquake in southern Hyogo Prefecture, such an increase was observed in three of the seven springs studied, and this phenomenon is similar to the increased concentrations of chloride ions and radon in groundwater, which have been reported as precursors to the earthquake.

The estimated volume of plate-derived water during this period exceeded 100,000 cubic meters, potentially weakening the fault and triggering the 1995 Kobe earthquake.

Moreover, this phenomenon is not unique to Arima. The Matsushiro earthquake swarm (1965–67) also displayed similar characteristics. Researchers have found that a substantial amount of water in Matsushiro hot springs originates from the Philippine Sea Plate.

Therefore, monitoring such hot spring water could offer valuable insights for earthquake prediction.