Antarctic ice sheet melting could raise sea levels by 20% by end of this century: Study

A new study from Harvard researchers revealed that global sea levels could rise by 20 per cent by the end of this century owning to the continuous melting of the West Antarctic Ice Sheet. The researchers used new calculations based on what they witnessed along with the ice sheets, which they’ve referred to as a “water expulsion mechanism”. 

The researchers explained that the mechanism happens when the solid base of the ice sheet begins to move upwards, decreasing the total weight of the ice sheet. In usual circumstance, they said that the solid base or “bedrock” remains below sea level. But when it lifts itself, the water from the surrounding area is pushed into the ocean, contributing to the global increase in sea levels. 

Jerry X. Mitrovica, the Frank B. Baird Jr. Professor of Science in the Department of Earth and Planetary Sciences and a senior author on the paper, said, “Every published projection of sea-level rise due to melting of the West Antarctic ice sheet that has been based on climate modelling, whether the projection extends to the end of this century or longer into the future, is going to have to be revised upward because of the work”. 

Sea-level amplified by 30% within 1,000 years 

According to the research, the predictions additionally also show that in the case of a total collapse of the ice sheet, the global sea level estimated would be amplified by an additional meter within 1,000 years.  Evelyn Powell, a Ph.D. in earth and planetary science in GSAS, said that if the West Antarctic Ice Sheet collapsed, the most widely cited estimate of the resulting global mean sea level rise that would result is 3.2 meters. She added that the team believes that the water expulsion mechanism will add an additional meter, or 30 per cent, to the total. 

During the research, the scientists even noticed more water expulsion from the West Antarctic ice sheet than they were expecting. They investigated how the expulsion mechanism affected sea-level change when the low viscosity, or the easy flowing material of the Earth's mantle beneath West Antarctica, is considered. Linda Pan, the co-author of the study, said that no matter what scenario the team used for the collapse of the West Antarctic Ice Sheet, they always found that this extra one meter of global sea-level rise took place. 

Now, the researchers hope that their calculations show fellow researchers that they need to incorporate both the water expulsion effect and the mantle's low viscosity beneath Antarctica. Pan said that sea-level rise doesn't stop when the ice stops melting. “The damage we are doing to our coastlines will continue for centuries," she added. 

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