Models warn Thwaites Glacier could rival entire Antarctic ice loss by 2067
The future of one of Antarctica's most iconic glaciers could be far more dramatic than scientists previously thought. Using satellite calibrated ice sheet models, a team of researchers from the University of Edinburgh found that the Thwaites Glacier in West Antarctica could be shedding 180–200 gigatonnes of ice per year by 2067—a rate roughly comparable to the entire Antarctic ice sheet's current mass loss. That would represent a stunning acceleration in ice loss from a single glacier and underlines urgent concerns about future contributions to sea level rise.
Thwaites Glacier is already one of the fastest changing and most closely watched glaciers on Earth, losing ice more than five times faster than in the 1990s. It drains a huge area of the West Antarctic Ice Sheet and outlets into the Amundsen Sea. In recent decades, observations from satellites have shown that it has been thinning and accelerating, losing more ice to the ocean than it gains from snowfall. This imbalance is what drives its contribution to global sea level rise.
Understanding how much ice could be lost in the coming decades is not just a matter of measuring what's happening now. Scientists rely on computer models that simulate the physics of ice flow, ocean melting, and changing surface conditions, but those models need to be calibrated against real observations—in this case, data on how fast the glacier surface is lowering and how the ice is moving.
Reshaping future scenarios
One of the key findings of the new study, published in Geophysical Research Letters, is that the way models are "trained" against observations strongly influences their long-term predictions. Models that were constrained using satellite measurements of surface elevation change (how the height of the glacier is decreasing over time) projected the largest future mass losses. Those projections suggest that by 2067, the rate of ice loss from Thwaites Glacier could equal what the entire Antarctic ice sheet currently contributes to sea level rise each year.