南极冰盖过去的临界点曾在一个十年内发生

自然-通讯，11月15日

最后一个冰河时代结束时，有八个时期全球气温升高导致南极洲大块冰山断裂。在这些时期中的大多数时期，冰山排放量的测量表明，南极冰盖在十年或更短时间内达到了不稳定的临界点；但这些临界点随后导致了持续几个世纪或几千年的冰量损失，以及相对快速的海平面上升。.

This apparent past sensitivity of Antarctica has serious implications for the impact from today’s global heating on the West Antarctic Ice Sheet in particular. As the authors conclude, “Emerging ice-sheet modeling suggests once initiated, retreat of the Antarctic Ice Sheet (AIS) can continue for centuries….Our findings are consistent with a growing body of evidence suggesting the recent acceleration of AIS mass loss may mark the beginning of a prolonged period of ice sheet retreat and substantial global sea level rise.” In other words, the observed response of Antarctica to the warming of recent decades could usher in a similarly self-sustaining and irreversible period of ice sheet retreat, with a corresponding rise in sea level of several meters globally.

该研究还表明，南极洲在越过临界点后重新稳定的所需时间取决于未来变暖的程度。这凸显了立即减少温室气体排放的必要性，以降低许多世纪灾难性海平面上升的风险，从而避免主要海岸线、城市和基础设施的损失。.

https://www.nature.com/articles/s41467-021-27053-6