The collapse of the West Antarctic ice sheet – which could cause catastrophic sea level rise – is not “inevitable”, researchers concluded in a study published Monday in Nature Communications.
Since the early 1990s, scientists have observed an acceleration in the melting of the ice in this area of Antarctica, under the effect of climate change caused by human activity. Some fear a now irreversible collapse of the ice sheet, which would continue regardless of future climate change.
It would thus be one of the climatic “tipping points” generating catastrophic chain reactions – in this case a significant rise in the level of the oceans. But a team of researchers in the United States and UK has just published a study showing that everything is not over.
They observed the evolution of West Antarctica, which is home to giant, highly unstable glaciers and contains enough ice to raise sea levels by 3.3 meters. Using satellite observations and data, they determined that the rate and extent of ice disturbances along the coast vary with local climatic differences.
The rate of ice sheet retreat thus slowed in a vulnerable region of the coast between 2003 and 2015. This slowdown was caused by changes in ocean temperatures, which are caused by variations in offshore winds.
“Ice cap collapse is not inevitable,” concluded Eric Steig, a professor at the University of Washington at Seattle. “It depends on how the climate will change in the coming decades, a change that we can positively influence by reducing greenhouse gas emissions,” he stressed.
Curb CO2 emissions
In these regions, the wind usually blows from the west and brings warmer and saltier water, which increases the melting of the ice. But the intensity of these winds had been weaker off the Edmonton Sea during the period under review, thus sparing the glacier some of this water which attacks it.
“There is a strong link between climate and the way ice behaves,” said Frazer Christie of the Scott Polar Research Institute in Cambridge. “We have the opportunity to mitigate ice loss in West Antarctica – if we curb our emissions of CO2 “, he concluded.
Anders Levermann, of the Potsdam Institute for Research on the Effects of Climate Change, a scientist who was not involved in the study published on Monday, praised the method used while stressing that the period studied corresponded “to a blink of eyes” from the point of view of the mirror. According to him, it is necessary to continue to predict a rise in the level of the oceans “with the hypothesis of a destabilization of theAntarctic western”.