In News: The first-of-its-kind study raises new concerns about how fast climate change is weakening Antarctica’s floating ice shelves and accelerating the rise of global sea levels.
- Antarctica’s coastal glaciers are shedding icebergs more rapidly than nature can replenish the crumbling ice, doubling previous estimates of losses from the world’s largest ice sheet over the past 25 years, a satellite analysis showed.
- The study’s key finding was that the net loss of Antarctic ice from coastal glacier chunks “calving” off into the ocean is nearly as great as the net amount of ice that scientists already knew was being lost due to thinning caused by the melting of ice shelves from below by warming seas.
- Taken together, thinning and calving have reduced the mass of Antarctica’s ice shelves by 12 trillion tons since 1997, double the previous estimate.
- The net loss of the continent’s ice sheet from calving alone in the past quarter-century spans nearly 37,000 sq km (14,300 sq miles), an area almost the size of Switzerland
- Antarctica is crumbling at its edges, and when ice shelves dwindle and weaken, the continent’s massive glaciers tend to speed up and increase the rate of global sea level rise.
- The consequences could be enormous.
- Antarctica holds 88% of the sea level potential of all the world’s ice.
- When ice shelves are stable, the long-term natural cycle of calving and re-growth keeps their size fairly constant.
- The accelerated glacial calving, like ice thinning, was most pronounced in West Antarctica, an area hit harder by warming ocean currents.
- But even in East Antarctica, a region whose ice shelves were long considered less vulnerable, are witnessing more losses than gains.
The losses measured from calving outpaced natural ice shelf replenishment so greatly that researchers found it unlikely Antarctica can return to pre-2000 glacier levels by the end of this century.
Source: Indian Express