The Greenland and Antarctic ice sheets have lost more than 500 billion tons annually since 2000, equivalent to six Olympic-sized swimming pools every second.
But climate models have so far underestimated their contribution to sea level rise, taking into account only rising temperatures and ignoring interactions between the atmosphere, oceans, ice sheets and some glaciers.
A study by researchers from South Korea and the United States established that if current climate policies were maintained, the melting of the ice sheet in Antarctica and Greenland would cause a rise in sea level of about half a meter between now and 2050.
The figure would increase to 1.4 meters in the worst case scenario, which implies a significant increase in greenhouse gas emissions.
The experts based their predictions on the basis of the different scenarios proposed by the experts of the United Nations Intergovernmental Panel on Climate Change (IPCC).
“Inflection point”
The research, published this week in the journal Nature Communications, also pinpoints when the uncontrollable melting of ice sheets and glaciers could accelerate.
“Our model sets thresholds of between 1.5°C and 2°C of warming — with 1.8 °C being our best estimate — for accelerated ice loss and sea level rise,” Fabian told AFP. Schloesser, of the University of Hawaii, a co-author of the study.
Temperatures have already risen by almost 1.2ºC worldwide since the pre-industrial era.
Scientists have long known that the West Antarctic and Greenland ice sheets — which could raise sea levels by as much as 40 feet in the long term — have “tipping points” beyond which their breakup is inevitable. .
But the temperatures associated with this phenomenon had never been precisely identified.
Other studies published this week in Nature show, on the other hand, that the Thwaites Glacier, in West Antarctica, is fracturing in an unprecedented way.
This glacier, the size of Great Britain, has already shrunk 14 km since the 1990s, but the phenomenon was not well understood due to a lack of data.