南极两大冰川正以至少五千年来最快的速度融化

Nature Geoscience, 9 June 2022

Over the past three decades, ice loss has more than doubled from the Thwaites and Pine Island glaciers in West Antarctica. These massive glaciers, which form part of the West Antarctic Ice Sheet (WAIS) are especially vulnerable to rapid melting. This is because they sit on sloping bedrock, where warm ocean water can intrude under floating parts of the glaciers, eroding them along their base. Such warm water currents therefore accelerate melting and can destabilize these glaciers, leading to potentially rapid collapse. Five thousand years ago, Earth’s climate was much warmer than it is today; yet during this period, the Thwaites and Pine Island glaciers were relatively stable. However, recent rapid ice loss has produced local fluctuations in sea level five times larger than previously recorded. These findings suggest that this region of West Antarctica is currently retreating at unprecedented rates. The accelerated loss of these two huge glacier basins alone will increase the flow of Antarctic ice into the ocean, contributing as much as 3.4 meters to global sea-level rise over the next several centuries.

https://www.nature.com/articles/s41561-022-00961-y