The melting of West Antarctic ice is expected to accelerate considerably in the coming decades and could raise sea levels, according to a study published this Monday, October 23, in the journal Nature Climate Change by researchers from the British Antarctic Survey. And this, even if the world respects its commitments to limit global warming.
Researchers have warned that humanity has “lost control” over the fate of ice shelves, these giant icy structures that float at the edge of the main ice sheet (a very extensive ice sheet, editor’s note) and which play a stabilizing role in slowing the drift and melting of glaciers in the ocean.
While Antarctica has already experienced accelerated ice loss in recent decades, scientists said the West Antarctic Ice Sheet, which contains enough water to raise ocean levels by several metres, could approach a “point climate tipping point.
The researchers found, using computer models, that faster melting of ice shelves is already inevitable in the coming decades due to warming oceans.
Is the ocean warming three times faster?
Even in a scenario where greenhouse gas (GHG) emissions are reduced and warming remains within the limits of the most ambitious goal of the Paris Agreement (i.e. 1.5°C compared to the era preindustrial), their results are substantially identical. Even in the best-case scenario, ocean warming could be three times faster in the 21st century than in the 20th century.
Kaitlin Naughten, lead author of the study, said researchers had “every reason to expect” that melting ice would contribute to sea level rise – already expected to reach one meter by the end of the century – although they did not. have expressly studied. .
“The melting of the West Antarctic ice shelf is one of the effects of climate change to which we will probably have to adapt,” he believes.
Millions of people around the planet currently live in low-lying coastal areas and some “coastal communities will have to be built around them or abandoned,” he adds.
“An attention call”
According to Alberto Naveira Garabato, professor of physical oceanography at the University of Southampton, this study is “sobering.”
“This illustrates how our past decisions have likely resulted in substantial melting of the West Antarctic Ice Sheet and subsequent sea level rise, which we will inevitably have to adapt to as a society for decades and centuries to come,” he told the Science Media Center.
But he stresses that it is also a “wake-up call” to reduce greenhouse gas emissions to avoid other serious climate consequences, including the melting of the East Antarctic ice sheet, currently considered more stable.
The study authors note that while a major reduction in emissions would not make much difference to the loss of the West Antarctic ice sheet this century, it could have a significant long-term impact, as the ice sheet would likely It will take centuries to recover. , if not millennia, to fully respond to climate change.
Jonathan Bamber, a professor at the University of Bristol’s school of geographic sciences who was not involved in the research, says the study is somewhat limited because the researchers used only one ocean model and did not explicitly study the effect of warming waters on oceans. sea levels. .
Source: BFM TV
