A new modeling study from scientists at UC San Diego’s Scripps Institution of Oceanography suggests that meltwater flowing out to sea from beneath Antarctic glaciers is making them lose ice faster.
The model’s simulations — published in a study today in Science Advances — suggest this effect is large enough to make a meaningful contribution to global sea-level rise under high greenhouse gas emissions scenarios.
The extra ice loss caused by this meltwater flowing out to sea from beneath Antarctic glaciers isn’t currently accounted for in the models generating major sea-level rise projections, such as those of the Intergovernmental Panel on Climate Change (IPCC). If this process turns out to be an important driver of ice loss across the entire Antarctic ice sheet, it could mean current projections underestimate the pace of global sea-level rise in decades to come.
According to Tyler Pelle, the study’s lead author and a postdoctoral researcher at Scripps:
“Knowing when and how much global sea-level will rise is critical to the welfare of coastal communities. Millions of people live in low-lying coastal zones and we can’t adequately prepare our communities without accurate sea-level rise projections.”
The study modeled the retreat of two glaciers in East Antarctica through the year 2300 under different emissions scenarios and projected their contributions to sea-level rise. Unlike previous Antarctic ice sheet models, this one included the influence of this flow of meltwater from beneath glaciers out to sea, which is known as “subglacial discharge.”
Jamin Greenbaum, co-author of the study and a researcher at Scripps’ Institute of Geophysics and Planetary Physics, added:
“I think this paper is a wake up call for the modeling community. It shows you can’t accurately model these systems without taking this process into account.”
Check out the full study here.