Troubling Study Reveals Greenland's Northern Glaciers in Peril, Signaling Potential for Dramatic Sea Level Rise
Greenland's northern glaciers face alarming instability, posing a significant threat of dramatic sea level rise, a recent study reveals
Greenland's massive glaciers at the top of the world, once believed to be fairly stable, are facing significant challenges, reveals a recent study. The warming of the ocean is causing rapid deterioration of Greenland's last remaining ice shelves, which in turn is destabilizing the adjacent glaciers. This poses a serious risk of "dramatic" repercussions for the rise in sea levels, as reported in a study published in the journal Nature Communications on Tuesday.
Ice shelves are ice formations that extend into the ocean, serving as barriers that prevent glaciers on land from flowing into the sea too quickly, thereby reducing ice melting. However, when these ice shelves melt and weaken, they enable more land-based ice to enter the ocean, contributing to the rise in sea levels.
A group of scientists conducted an analysis on eight ice shelves that support glaciers in northern Greenland. Collectively, these ice shelves contain a significant amount of ice, capable of elevating sea levels by 2.1 meters or nearly 7 feet if they were to collapse and fully melt.
"These glaciers in northern Greenland have remained relatively stable, making them the largest and most significant glaciers of the ice sheet," stated Romain Millan, a glaciologist at the Grenoble Alpes University in France and co-author of the study.
But this appears to no longer be the case, according to the study.
West Antarcticahome to the Thwaites Glacier, also known as the "Doomsday glacier"is the continent's largest contributor to global sea level rise.
Jeremy Harbeck/OIB/NASA
Rapid melting in West Antarctica is inevitable, posing severe implications for the rise in sea levels, according to a study. Millan and his colleagues utilized numerous satellite images, climate models, and field measurements to gain a deeper insight into the factors behind, as well as the timing of, past and present alterations in the ice shelves.
The study revealed a significant and extensive rise in the deterioration of ice shelves. Over the course of nearly five decades, the study observed that the ice shelves, which are crucial in supporting glaciers in northern Greenland, have experienced a reduction of more than 35% in their overall volume. Furthermore, the research indicated that three of these ice shelves have completely collapsed since the early 2000s, while the remaining five are currently melting and causing instability in nearby glaciers.
Millan, the researcher, highlighted that this finding is particularly noteworthy as it provides novel insights into the weakening of the ice shelves. Until now, it was widely believed that this specific area of Greenland demonstrated remarkable stability.
The Petermann Glacier, located in northwestern Greenland, is a major glacier that links the Greenland ice sheet to the Arctic Ocean. Over the past few years, there has been a notable increase in the speed at which the ice flows in the Petermann Glacier.
Copernicus Sentinel-2/ESA
The ice loss came from a mixture of factors, the study found, including increased calvingchunks of ice breaking off to form icebergs  and surface melting.
Between 2000 and 2020, a significant factor driving ice melt was basal melting caused by warm ocean currents. According to the study, there was a noticeable rise in the rate of basal melting, which closely correlated with the increase in ocean temperature. The scientists observed a direct consequence on glaciers, with the ice shelves melting and causing the grounding lines – the point at which the glacier loses contact with the ground and begins to float – to retreat.
"These natural boundaries serve as crucial indicators of glacier stability," Millan stated. He further explained that as the grounding line recedes, there is an accompanying increase in ice discharge into the ocean.
Should the oceans continue to warm, Millan warns of the potential permanent weakening of the ice shelves. "Moreover, in due time, these shelves may even collapse, resulting in substantial ramifications for the Greenland ice sheet's contribution to rising sea levels."
Between 2006 and 2018, the melting of Greenland's ice sheet accounted for more than 17% of the documented rise in sea levels, states the report. Millan explained that although it is challenging to determine specific timelines for the occurrence of a collapse, notable changes have occurred rapidly since the early 2000s.
After the ice shelf of the Zachariæ Isstrøm glacier collapsed in 2003, there was a twofold increase in the discharge of ice into the ocean, as reported by the study. Millan's visits to the glacier in 2016 and 2017 revealed alarming changes. He described the scene as "a chaotic array of tabular icebergs."
A glacier in northern Greenland on October 4, 2023. The region's glaciers are destabilizing as the ice shelves melt, according to the new study.
Thomas Traasdahl/Ritzau Scanpix/AFP/Getty Images
The fate of the glaciers is closely linked to global efforts in reducing pollution that contributes to the heating of the planet, according to Millan. The report emphasizes the importance of ongoing monitoring to gain a deeper understanding of how the ice shelves will react to climate change. Additionally, it highlights the need to further explore the intricate process of basal melting and its potential implications for rising sea levels.
The report states that this will give us a better understanding of the future of these glaciers and the larger ice shelves in Antarctica. A recent study conducted in Antarctica has discovered that the rapid melting of the continent's ice shelves may now be inevitable due to melting occurring from underneath. Sophie Nowicki, an expert on ice sheets from the geology department at the University at Buffalo, who was not part of the research, emphasized the importance of the study's findings in identifying the causes and triggers of changes to Greenland's ice sheet.
The longer-term and comprehensive perspective on the evolution of ice shelves is the new aspect, she told CNN. What is impressive about this study is that it offers a more precise understanding of the timing and extent of the change associated with the melting of the ice shelf due to ocean temperature.
According to Nowicki, this study further contributes to the general comprehension of the response of polar regions to the climate crisis caused by human activities.
According to her, the poles were previously considered dull, but the advent of satellite observation by scientists about forty years ago has revealed that they are actually dynamic and highly vulnerable areas. She pointed out that as global warming persists, we ought to be worried about the rapidity of these changes, although they should not catch us off guard.
