南极冰盖的歇斯底里
Julius Garbe1,2, Torsten Albrecht1, Anders Levermann1,2,3
1Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, Potsdam, Germany.
Nature
|September 24, 2020
概括
南极冰层的崩是不可逆转的, 超过2°C的气候变暖将导致西南极洲崩,6-9°C之间出现显著的冰层损失,威胁全球海平面.
科学领域:
- * 冰川学和气候科学
- * 地球系统动力学
- * 海平面上升研究
背景情况:
- 南极冰层拥有地球一半以上的淡水, 成为全球海平面上升的关键因素.
- 它的稳定性对沿海地区至关重要,但缺乏对其应对变暖的全面分析.
- 冰,大气,海洋和固体地球之间的复杂反会导致对温度变化的非线性反应.
研究的目的:
- 在全球变暖的各个阶段对南极冰层的稳定性进行综合分析.
- * 确定不可逆转的冰损失的临界温度值.
- * 在不同变暖情景下量化南极洲海平面上升的贡献.
主要方法:
- 使用平行冰盖模型 (PISM) 进行先进的冰盖模拟.
- * 分析了冰盖稳定性,以应对工业化前平均水平以上的全球变暖水平.
- * 将模型输出与古数据进行比较,以验证冰盖行为的发现.
主要成果:
- * 已发现多个温度值,导致南极冰层不可逆转地消失.
- 由于海洋冰盖的不稳定性, 西南极洲将在2°C的温度下部分崩.
- * 6-9°C的升温将使南极失去超过70%的冰量,主要是通过地表升高反.
- 超过10°C的升温将导致南极洲几乎没有冰.
- 冰盖每摄氏度升温的海平等效贡献随着温度升高而显著增加 (1.3 m/°C至2°C,2.4 m/°C在2-6°C之间,和~10 m/°C在6-9°C之间).
- * 观察到歇斯底里症:即使温度下降,冰盖的配置也不会恢复.
结论:
- 如果未能实现"巴黎协定"的目标,南极洲的海平面贡献将大幅增加.
- * 已识别的变暖值表明南极冰层的消失将不可逆转.
- 西南极冰层的回收能力有限,需要显著减少变暖.
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