Climate change drives increased melting of glaciers around the world, including about 280 glaciers that drain ice from Greenland’s massive ice sheet through deep fjords into the ocean. Greenland’s ice has the potential to increase global sea level by more than 7 meters, but the exact effects and their timing are difficult to predict.
In a new review, Catania et al. synthesize recent progress and highlight ongoing challenges in understanding and forecasting the future of Greenland’s ice sheet–draining glaciers. They emphasize that a deeper understanding is needed to predict not just the resulting sea level rise but impacts on ocean circulation and other ocean properties, nutrient cycling, and ecosystem functioning—from local to global scales.
Advances in computational modeling and observational capabilities, especially via aircraft and satellites, have greatly improved knowledge of the interconnected processes that underlie depletion of the Greenland ice sheet. For example, scientists now know that meltwater from the surface of a glacier flows under the ice and promotes submarine melting where the glacier meets the sea.
Much of the uncertainty in predicting the future of Greenland’s ice arises from the difficulty of observing and modeling complex links between processes that occur where ice meets atmosphere, ice meets ocean, or ice meets land. Models must account for numerous factors at varying spatial and temporal scales, including ocean temperature, the shape and depth of fjords, iceberg calving, shifts in global climate, local weather patterns, and many more.
The researchers recommend several courses of action to address these uncertainties. They stress the need for improved technology to conduct long-term observations at the boundaries between ice and ocean and between ice and land. They also call for stronger links to be made between models of glaciers and models of the atmosphere and ocean.
To accomplish these goals, the authors say, glacier researchers should strive to make their data and visualizations easily accessible for colleagues and stakeholders. They also recommend efforts be made to increase diversity within the community of researchers studying Greenland’s ice and to expand collaborations with researchers from other fields as well as with representatives from Greenlandic communities. (Journal of Geophysical Research: Earth Surface, https://doi.org/10.1029/2018JF004873, 2020)
—Sarah Stanley, Science Writer