Scientists working at the National Aeronautics and Space Administration (NASA), and the European Space Agency (ESA), conducted a series of aerial surveys over Greenland using two drones, the CryoSat-2 and the ICEsat-2. Greenland is the world’s largest island and 80% of its surface is covered by a single ice sheet or glacier with an average thickness of 1.67 kilometers. The aim of the survey was to monitor the thickness of this ice sheet over time. The results were worse than expected and show that the ice sheet is melting faster than ever.
From 2010 to 2023, the ice sheet has thinned at an average of 1.2 meters per year. The thinning around the outer edges of the ice sheet has been five times worse, at an average of 6.4 meters year. Greenland’s outlet glaciers (valley glaciers that originate from ice sheets but move towards the sea) have taken the biggest hit. Peak thinning was recorded at Sermeq Kujalleq, in west central Greenland at 67 meters and at Zachariae Isstrøm, in the northeast of Greenland, at 75 meters.
Over the 13 years of survey, the ice sheet shrank by a total of 2,347 cubic kilometers, which is enough water to completely fill Lake Victoria in Africa. 2012 and 2019 proved to be the worst years, when the average summer temperatures rose to above 48⁰C. This caused the ice sheet to lose about 400 cubic kilometers or 400 trillion liters of water! Rising sea levels is the biggest and most obvious concern; however, this excess water also disrupts ocean currents and global weather patterns. Scientists have predicted that if the thinning continues at the same rate, Europeans will have to endure harsher and colder winters, while Australian summers are set to become hotter and wetter.
NASA’s ICEsat-2 measured the thickness of the ice sheet by sending laser pulses towards it and timing how long they took to reflect. On the other hand, ESA’s CryoSat-2 used radar to measure the height of the ice sheets. Thorsten Markus, a project scientist from NASA for the ICESat-2 mission, said, “Understanding the similarities and differences between radar and laser ice sheet height measurements allows us to fully exploit the complementary nature of those satellite missions.”
Tommaso Parrinello, manager of the CryoSat-2 mission, further said, “This collaboration represents an exciting step forward, not just in terms of technology but in how we can better serve scientists and policymakers who rely on our data to understand and mitigate climate impacts.”
If all of Greenland’s ice sheet was to melt, sea levels across the globe would rise by 7.4 meters or 24 feet – the height of the BFG (Big Friendly Giant), a character from Roald Dahl’s famous children’s novel. We must act now to limit climate change, ocean acidification, and other threats to protect Greenland’s majestic ice sheet!
References:
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL110822
https://phys.org/news/2024-12-esa-nasa-satellites-joint-picture.html