Science | Antarctic thaw could reach a critical point in 2060, study finds

2060 is the year set by a group of scientists. If “ambitious measures” are not taken beforehand to stop the global warming, in line with the Paris Agreement, “no human intervention” could stop the rise of the sea, from 17 to 21 centimeters in 2100 due to the melting of Antarctica.

The study published this Wednesday Nature is based on a model, with the use of satellite observations, paleoclimate data and machine learning, to predict how the Antarctica this century depending on whether the objective of the Paris Agreement (2015) of not exceeding two degrees of global warming.

Experts from the universities of Rutgers and Massachusetts Amherst (USA) indicate that current international policies are likely to provoke a global warming three degrees, which would accelerate “drastically” the rate of sea level rise, due to a rapid retreat of the ice sheet between 2050 and 2100.

“If the rhythm of global warming continues on its current trajectory, we will reach a turning point in 2060, from which these consequences would be irreversible on time scales of several centuries “, they warn.

“Major leap in the thaw”

In that scenario, the risk that the ice shelves around the perimeter of the ice sheet would melt would increase significantly and their collapse would trigger a rapid melting of the ice sheet. Antarctica.

The study models the impact of various warming scenarios on the ice sheet of the Antarctica. If the most optimistic temperature targets were reached, between 1.5 and 2 degrees, it would contribute to raising the sea level by 6 to 11 centimeters in 2100.

But, if the current heading is held towards 3 degrees, the model points to a significant jump in the thaw.

Thus, the authors warn that, “unless ambitious measures are taken to halt warming before 2060, no human intervention, including geoengineering (removal of carbon dioxide from the atmosphere and its sequestration or storage), could stop the rise in sea level from 17 to 21 centimeters just because of the thaw of the Antarctica at 2100 “.

“Globally catastrophic levels”

Looking at the longer term, in 2300 and without measures to mitigate greenhouse gas emissions, the contribution of the Antarctica at sea rise it would reach “globally catastrophic levels of ten meters or more.”

Research indicates that the architecture of the Antarctic ice sheet plays a key role in ice loss.

That layer naturally slides into the ocean, where it begins to melt, but that movement occurs slowly thanks to a ring of ice shelves, which act as dikes, preventing the edges of the ice sheet from collapsing.

As the global warmingAs ice shelves thin, meltwater can deepen the cracks and cause them to completely disintegrate.

This allows the ice sheet to flow into the faster warming ocean and the exposed edges of the ice sheet to break away, raising sea levels.

These processes are currently observed in Greenland, but have not become widespread, at least for the time being, in the colder ice sheet of the Antarctica.

Lead study author Rob DeConto noted that, “if the world continues to warm, the huge glaciers of the Antarctica they could start to behave like their smaller Greenland counterparts, which would be disastrous in terms of rising sea levels. “

Not meeting the temperature targets of the Paris Agreement and allowing the extensive loss of the supporting ice shelves represents, for the research team, “a possible turning point in the future of the Antarctica“.

(With information from EFE)

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