If world leaders and policy makers can’t find a way to reduce emissions and limit warming to 2 degrees Celsius, the target set by the Paris Agreement, new models suggest runaway Antarctic ice losses will trigger dramatic sea level rise.
According to a study published on Wednesday in the journal Nature, current global warming trends have planet Earth set to overshoot the Paris Agreement targets by 2060.
If that happens, researchers and their models predict the destabilization of Antarctica ice will guarantee between 17 and 21 centimeters of unstoppable sea level rise by the end of the century.
To limit the damages caused by climate change, whether by prolonged droughts or rising seas, scientists generally agree that world leaders should work to limit warming to 1.5 degrees Celsius above preindustrial levels – the most ambitious target set by the Paris Agreement.
However, climate scientists estimate policy makers can also ensure a livable planet by meeting a slightly less aggressive target and limiting warming to 2 degrees.
But if world leaders can’t find a way to meet one of the two Paris Agreement targets, scientists have said, all bets are off.
For the new study, a team led by researchers at the University of Massachusetts Amhurst looked at how Antarctica’s ice is likely behave under different warming scenarios.
According to the analysis, if global warming is limited to between 1.5 and 2 degrees, the most up-to-date Antarctic ice loss models predict the Southern Continent’s ice sheet would contribute between 6 and 11 centimeters of sea level rise by 2100.
If global warming approaches 3 degrees above preindustrial temperatures, models predict Antarctic ice loss will contribute 17 to 21 centimeters of sea-level rise by the end of the century.
If current warming trends hold, Earth and the Antarctica ice sheet will reach the tipping point for runaway sea level rise by 2060.
Because significant amounts of ice sheet destabilization gets baked in as the climate warms, even moderate warming will ensure Antarctica continues to suffer significant ice losses over the next few centuries.
The latest models suggest continued warming beyond Paris Agreement targets will ensure seas rise upwards of 10 meters by 2300.
Conversely, the models show that if policy makers can meet Paris Agreement targets, longterm sea level rise can be limited to 1 meter.
Some studies have shown Antartica’s ice sheet will continue to melt for the next 300 years, even if warming is dramatically slowed. But if warming continues, melting and sea level rise will accelerate more dramatically and faster, researchers say.
Researchers suggest the source of Antarctica’s vulnerabilities is found along the coast.
As the continent’s coastal glaciers shrink, they become increasingly vulnerable to warm water currents and less able to slow the descent of inland ice.
This pattern of accelerating ice loss has become especially apparent in Greenland, where warming trends have been more pronounced.
“If the world continues to warm, the huge glaciers on Antarctica might begin behaving like their smaller counterparts on Greenland, which would be disastrous in terms of sea level rise,” study first-author Rob DeConto, co-director of Amhurst’s School of Earth and Sustainability, said in a press release.
Recent studies have shown melting rates across much of Greenland have dramatically accelerated in recent decades.
One study even showed Greenland is now losing four times as much ice each year as it was nearly two decades ago.