Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden.
Nat Commun. 2022 May 9;13(1):2519. doi: 10.1038/s41467-022-29529-5.
Floating ice shelves buttress inland ice and curtail grounded-ice discharge. Climate warming causes melting and ultimately breakup of ice shelves, which could escalate ocean-bound ice discharge and thereby sea-level rise. Should ice shelves collapse, it is unclear whether they could recover, even if we meet the goals of the Paris Agreement. Here, we use a numerical ice-sheet model to determine if Petermann Ice Shelf in northwest Greenland can recover from a future breakup. Our experiments suggest that post-breakup recovery of confined ice shelves like Petermann's is unlikely, unless iceberg calving is greatly reduced. Ice discharge from Petermann Glacier also remains up to 40% higher than today, even if the ocean cools below present-day temperatures. If this behaviour is not unique for Petermann, continued near-future ocean warming may push the ice shelves protecting Earth's polar ice sheets into a new retreated high-discharge state which may be exceedingly difficult to recover from.
浮动冰架支撑着内陆冰，并限制了基岩冰的排放。气候变暖导致冰架融化，最终冰架断裂，这可能会加剧海洋边缘冰的排放，从而导致海平面上升。如果冰架崩塌，即使我们实现了《巴黎协定》的目标，也不清楚它们是否能够恢复。在这里，我们使用一个数值冰盖模型来确定格陵兰岛西北部的彼得曼冰架是否能够从未来的破裂中恢复过来。我们的实验表明，像彼得曼冰架这样的受限冰架在破裂后的恢复是不太可能的，除非冰山崩解大大减少。即使海洋温度降至目前水平以下，彼得曼冰川的冰排放仍将比今天高出 40%。如果这种行为对彼得曼冰架来说并非独一无二，那么未来的近岸海洋变暖可能会将保护地球极地冰盖的冰架推向一个新的后退高排放状态，而这种状态可能极难恢复。
