Rising snowfall in Antarctic may help offset global sea-level surge

New York: More temperature could mean increased snowfall in Antarctica which could in turn help reduce the global sea-level rise by 51 to 79 millimetres by 2100, according to a new study.

When Antarctica's air temperature rises, moisture in the atmosphere increases. That should mean more snowfall on the frozen continent, the researchers noted.

The expectation of more snowfall is something of a silver lining as temperatures rise. Global warming is already increasing sea level through melting ice and thermal expansion. 

"Increased snowfall over Antarctica is the sole process connected to global warming that is thought to have a significant mitigating effect on global sea level rise," said lead author Michael Previdi, Professor at Columbia University's Lamont-Doherty Earth Observatory in New York. 

"While the magnitude of this effect is uncertain, it is likely that the balance of different processes determining Antarctica's net contribution to global sea level rise will be decidedly different in the future than it has been in the recent past," Previdi noted.

On a continental scale, surface mass balance is the difference between the amount of snowfall that accumulates and the amount of snow lost to sublimation. 

It affects global sea level because the amount of water on earth is essentially constant, so when more water is stored as snow or ice on land, less water is available to contribute to rising seas.

For the study, published in the journal Environmental Research Letters, the researchers evaluated surface mass balance simulations from 35 coupled atmosphere-ocean climate models, which simulate the physical forces that affect Antarctica.

The models allow scientists to quantify both the human influence on surface mass balance and the influence of natural variability. 

The analysis showed that rise in snowfall could help reduce the amount of global sea level rise by 51 to 79 millimetres by mid-century.