There is evidence that a self-sustaining ice discharge from the West Antarctic Ice Sheet (WAIS) has started, potentially leading to its disintegration. The associated sea level rise of more than 3m would pose a serious challenge to highly populated areas including metropolises such as Calcutta, Shanghai, New York City, and Tokyo. Here, we show that the WAIS may be stabilized through mass deposition in coastal regions around Pine Island and Thwaites glaciers. In our numerical simulations, a minimum of 7400 Gt of additional snowfall stabilizes the flow if applied over a short period of 10 years onto the region (−2 mm year−1 sea level equivalent). Mass deposition at a lower rate increases the intervention time and the required total amount of snow. We find that the precise conditions of such an operation are crucial, and potential benefits need to be weighed against environmental hazards, future risks, and enormous technical challenges.

Snapshots for a set of three simulations (shown in Figs. 2 and 3 of the paper)Forcing_8000Gt_20yr --> forcing with 8000 Gt of additional snow over 20 yrForcing_8000Gt_40yr --> forcing with 8000 Gt of additional snow over 40 yrNoForcing_Reference --> no addition of snow

Supplement to: Feldmann, Johannes; Levermann, Anders; Mengel, Matthias (2019): Stabilizing the West Antarctic Ice Sheet by surface mass deposition. Science Advances, 5(7), eaaw4132