Ice sheets around the world have been retreating over the last few decades, but Greenland’s ice sheet has been shrinking at a particularly fast clip since the ’90s. New satellite observations have revealed the extent of this retreat, finding that Greenland has lost about 5,091 square kilometres of ice over the past four decades. More specifically, the ice sheet shrank by an average of 218 square kilometres every year since January 2000, according to the analysis. The authors note that this loss does not appear to substantially contribute to sea level rise but may play a part in ocean circulation patterns and how heat energy is distributed across the planet.
Funder: This research was supported by the NASA Cryospheric Science and MEaSUREs programmes and was conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration ©2023. All rights reserved.
From: Springer Nature
The Greenland Ice Sheet, the second largest in the world, has lost approximately 5,091 square kilometres of ice since 1985, according to a study in Nature. Although that amount has had a relatively small impact on sea level rise, the ice loss may have implications for ocean circulation and thus the distribution of global heat energy.
Ice sheets across the world have experienced retreat over the past several decades, with the Greenland Ice Sheet in particular experiencing a period of accelerated mass loss since the 1990s. Climate models anticipate with a high level of certainty that this loss of ice in Greenland will continue, but research into how the ice sheet has previously retreated could offer a glimpse into its future behaviour.
Chad Greene and colleagues used satellite imagery to establish 236,328 glacial terminus positions from 1985 to 2022. From this, the authors quantified the extent of calving — the process of ice breaking off at the terminus of a glacier — and changes to the edges of the ice sheet and thus total ice area lost. The authors found that the Greenland Ice Sheet had lost about 5,091 square kilometres of ice over the past four decades. This area equates to approximately 1,034 gigatonnes (1,034 trillion kilograms) of ice. More specifically, the ice sheet shrank by an average of 218 square kilometres every year since January 2000 according to the analysis. The authors further note that this retreat does not appear to substantially contribute to sea level rise but may play a part in ocean circulation patterns and how heat energy is distributed across the planet.
Greene and co-authors also found that some of the glaciers in the Greenland Ice Sheet that saw the greatest difference between winter growth and summer retreat in a single year (including Jakobshavn Isbræ and Zachariæ Isstrøm) were also the glaciers that retreated the most from 1985 to 2022. This indicates that seasonal variability of glaciers could be a predictor of long-term retreat.