Climate change is causing a rapid decline in the ice surrounding the South Pole, and new research highlights that this might trigger a centuries-long phase of ice retreat. A study recently published in Nature Communications looks at past melting periods of the Antarctic Ice Sheet (AIS) to learn about what current melting might entail. The researchers found that multiple melting phases in the past destabilized the world’s largest ice sheet in as short a time as a decade. These rapid retreats were then responsible for “contributing to global sea-level rise for centuries to a millennium” before the AIS re-stabilized.
The international team of researchers analyzed the possible future of the AIS and found a host of variables supporting the possibility of long-term melting. These range from evidence of ice retreat in similar past events to modern-day tipping point analysis. A tipping point would be a threshold of change past which there is no immediate way to return to the prior state. In this case, the AIS could reach a point of ice retreat due to warming that continues even if global temperatures were brought back down to pre-warming levels. The melting would become self-propagating and continue regardless of lower temperature; the tipping point would have been reached.
If climate change-induced warming can destabilize the natural systems and waters around Western Antarctica, the study notes that the ice sheet “is projected to irrevocably contribute at least 3 m to [global mean sea-level rise] on centennial- to millennial-scales.” While this would occur over long periods of time, it would be in addition to sea-level rise from other sources. The tandem increase in water levels could spell disaster for coastal cities and communities. Such tragic possibility should motivate even greater climate mitigation action, or else we and dozens of future generations may suffer from centuries-long “self-sustaining and irreversible ice-sheet retreat.”
Source: Nature Communications