Could the Answer to Saving the West Antarctic Ice Sheet Be Man-Made Snow?
A team of scientists believes it might be possible to stabilize the West Antarctic Ice Sheet (WAIS) by using large quantities of artificial snow. Using computer models they have shown that this could prevent a catastrophic collapse of the ice sheet into the ocean.
What happens if the WAIS destabilizes?
According to estimates, marine-based ice sheets in Antartica hold enough water to raise global sea levels by more than 20 meters.
"It is prone to marine ice sheet instability and increasing evidence from satellite observations and numerical simulations suggest that a self-sustaining discharge from West Antarctic has been initiated and might not be stoppable by reduction of greenhouse gas emissions," Feldmann et at 2019.
If their worst fears were to be realized then, according to their estimates, any sea-level rise above 3 meters could be catastrophic. Large global population centers the likes of Calcutta, Shanghai, New York City and Tokyo would face some serious challenges.
What do they propose to do about it?
Johannes Feldmann of the Potsdam Institute for Climate Impact Research, RD1 - Earth System Analysis, Potsdam, Germany, and his co-authors propose a radical solution to this perceived threat.
Using computer models, like 3-D Parallel Ice Sheet Model (PISM) they have shown that the solution might be artificial snow from seawater. By pumping seawater from coastal regions surrounding the WAIS and converting it to snow, it might be possible to prevent the ice sheet catastrophically sliding into the ocean.
The plan is to increase the mass of snow at the point near where the ice sheet reaches the ocean. This, they believe, should prevent it from breaking off into the ocean.
"[The] West Antarctic Ice Sheet can 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. This is equivalent to a global sea-level drop of about 2 mm yr-1 if the mass is taken out of the ocean."
They were quick to point out that the timing of such an undertaking is critical. If the mass deposition of artificial snow is at too low a rate over a longer period of time, much more man-made snow would be needed.
By their estimates, for every decade that goes by, an additional 500 Gt would be needed to provide the desired effect.
How much energy will they need for this?
This kind of project won't be easy and, more importantly, is going to need a lot of energy. But where will it come from?
"The power required to pump ocean water in the equivalent of 1 mm yr-1 to the medium height of the stabilization region in order to [deposit] snow on the ice sheet is approximately 90 GW, and is available in the regional wind field," they said.
"Although our findings suggest that the West Antarctic Ice Sheet can in principle be stabilized by mass deposition, we find that the precise conditions of the intervention are crucial and potential benefits need to be weight against environmental hazards, future risks and enormous technical challenges implied in such an operation," Feldmann et al continued.
The authors caution that while the findings offer a potentially feasible and less dangerous solution compared to other proposed methods, they say that implementing their approach would be incredibly costly, present immense technical challenges and may harm sensitive marine ecosystems.
The study was originally published in the journal Science Advances.