Meeresspiegelanstieg doppelt so hoch wie bisher angenommen?
Sea levels could rise far more rapidly than expected in coming decades, according to new research that reveals Antarctica’s vast ice cap is less stable than previously thought.
The UN’s climate science body had predicted up to a metre of sea level rise this century - but it did not anticipate any significant contribution from Antarctica, where increasing snowfall was expected to keep the ice sheet in balance.
According a study collapsing Antarctic ice sheets are expected to double sea-level rise to two metres by 2100, if carbon emissions are not cut.
Previously, only the passive melting of Antarctic ice by warmer air and seawater was considered but the new work added active processes, such as the disintegration of huge ice cliffs.
The new research follows other recent studies warning of the possibility of ice sheet collapse in Antarctica and suggesting huge sea-level rises. But the new work suggests that major rises are possible within the lifetimes of today’s children, not over centuries.
“The bad news is that in the business-as-usual, high-emissions scenario, we end up with very, very high estimates of the contribution of Antarctica to sea-level rise” by 2100, said Prof Robert DeConto, who let the work. But if emissions were quickly slashed to zero, the rise in sea level from Antarctic ice could be reduced to almost nothing.
“This is the good news,” he said. “It is not too late and that is wonderful. But we can’t say we are 100% out of the woods.” Even if emissions are slashed there remains a 10% chance that sea level will rise significantly.