Rapid Ice Melt in Amundsen Sea, West Antarctica

GS Paper III Environment and Ecology

Context:

The rapid melting of West Antarctica’s ice sheet due to warm waters around it is now unavoidable, no matter how much carbon emissions are cut, according to a new study.

To conduct the analysis, the scientists have used a high-resolution computer model of the Amundsen Sea to provide the most comprehensive assessment of warming in West Antarctica to date.
Scientists have used the model to run many different simulations of the 21st century, totalling over 4,000 years of ocean warming and ice-shelf melting in the Amundsen Sea.

Amundsen Sea

Amundsen Sea is an arm of the Southern Ocean, the Amundsen Sea lies off the coast of Western Antarctica’s Marie Byrd Land.
The eastern and western extent of the Amundsen Sea are marked by the Cape Flying Fish and Cape Dart, respectively.
The Thwaites Ice Tongue extends into this sea which remains ice-covered in most parts.

Amundsen Sea

Ocean warming and ice-shelf melting in the 1.5°C scenario is statistically the same as in a mid-range scenario, which is closer to what existing pledges to reduce fossil fuel use over the coming decades would produce.
- This will most likely lead to an increased sea level rise, which will affect coastal communities across the world, including in India.

About Ice Sheet:

An ice sheet is essentially a mass of glacial ice that covers more than 50,000 square kilometers of land — roughly large enough to blanket Uttarakhand in ice.
There are two major ice sheets in the world: Greenland ice sheet and Antarctic ice sheet.

Amundsen Sea

Melting of Ice Sheets: There are various processes through which ice sheets melt. One of them is when warm ocean waters melt ice shelves — the edges of an ice sheet which floats on the ocean.Even under a best-case scenario of limiting global warming to 1.5 degree Celsius above pre-industrial levels, water in West Antarctica will continue to get warmer three times faster than in the 20th century, leading to an increased melting of the region’s ice sheet.
Sea-level rise: The melting West Antarctic ice sheet is just one contributor to sea level rise, which is just one impact of climate change.
Climate Change Impact: Some impacts of climate change can no longer be avoided, and substantial ice loss in West Antarctica is probably one of them.
- But, climate change is not all or nothing, and there are many other impacts which we can still avoid or limit: like the loss of the East Antarctic Ice Sheet, or the severity of heatwaves, droughts, and extreme rainfall.

News Source: The Indian Express