What the study found
The study found that uncertainty in bed topography, meaning the shape and elevation of the ground beneath the Antarctic Ice Sheet, has a large effect on projections of Antarctic ice evolution. The authors report that these uncertainties can change estimates of Antarctica's sea-level contribution by more than 40 cm by 2150 and 1 m by 2300.
Why the authors say this matters
The findings indicate that errors in bedrock elevation are a critical but underexplored source of uncertainty in Antarctic ice-sheet projections. The authors conclude that additional observations in critical regions are needed to help reduce these systemic uncertainties.
What the researchers tested
The researchers used simulations of Antarctic ice-sheet evolution at both continental and regional scales. They compared the effects of bed topography uncertainties, using error estimates reported in BedMachine Antarctica, with the effects of different climate forcing scenarios.
What worked and what didn't
Bed topography uncertainty affected projected sea-level contribution by more than 40 cm in 2150 and 1 m in 2300, according to the simulations. The impact was especially important for grounding line retreat and mass loss in the Amundsen Sea, Ross, and Filchner-Ronne basins, and it was even larger in higher-resolution regional and glacier-scale simulations. The abstract also says that the influence of bedrock uncertainties produced more variation in grounding line positions and mass change than seen in the broader-scale cases.
What to keep in mind
The abstract does not describe detailed limitations beyond the use of reported error estimates from BedMachine Antarctica. The findings are based on simulations, so they describe modeled projections rather than direct observations of future ice-sheet change.
- Uncertainty in Antarctic bed topography can change projected sea-level contribution by more than 40 cm by 2150 and 1 m by 2300.
- The effect of bed topography uncertainty is described as comparable to the effect of different emission scenarios.
- The Amundsen Sea, Ross, and Filchner-Ronne basins are highlighted as especially sensitive areas.
- Higher-resolution regional and glacier-scale simulations show even larger effects from bedrock uncertainty.
- The authors say more observations are needed in critical regions to reduce systemic uncertainty.

