How do the melting of the Arctic ice… · toppers’ answers, UPSC 2021

Toppers wrote this one in a test series: “The Arctic and Antarctic regions are both experiencing sea ice loss, but the rates and patterns of shrinkage are remarkably different." Discuss the factors that contribute to the differential shrinkage of sea ice in these polar regions. (15M)”

Raj Krishna JhaAIR 8 · CSE 2024 · 294 wordsTheir whole copy

Opening

The polar regions of the Earth are the worst affected by the climate change induced global warming. Retreating glaciers have been observed at both the regions, albeit the rates are different.

Body · points and prose

Arctic & Antarctic region facing sea loss:

Due to polar amplification ↳ caused by positive albedo feedback loop.

Diagram

[Ice loop: warming sea -> ice melts -> albedo reduces -> heat increases -> back to warming sea] [Water vapor loop: water vapor increases -> absorption of heat increases -> intensity further heating -> leads to warming of sea] Fig: Polar amplification (ice) Fig: Polar amplification (water vapor)

Changing upper air circulation. ↳ led to polar vortex weakening → Reduced Anticyclonic conditions at poles. → Temperature increased.
Ocean sea water heating ↳ due to global warming warm oceanic waters reaching the poles through oceanic current. → led to glacial melting.
Ozone Depletion ↳ aided by Chloro-floro & Hydro-chloro florocarbons. ↳ Exposure to Ultraviolet rays has increased.
Global atmospheric temperature rise ↳ as per IPCC, 1.2°C temperature rise on average has globally occurred compared to pre-industrial level (6th assessment report).

Factors contributing differential shrinkage

Unequal land mass distribution ↳ Arctic sea is surrounded by extensive land masses of US, Canada, Russia & Greenland. ∴ It is affected significantly by land temperature changes. → Antarctica is more open.

Diagram

[Circular map sketch with Canada, US, Russia, Norway, Greenland surrounding the Arctic sea] Fig: Arctic sea

Thus, Antarctica undergoes less heating caused by land mass.

(2) Human exploitation ↳ due to closeness with human settlement (eg. Eskimos), compared to Antarctica, Arctic gets more impacted by human factors. ↳ eg: ongoing attempts for initiating sea-shelf exploration of oil. ↳ Submarine movement in Arctic.

(3) Comprehensive treaty ↳ for fair usage of Antarctica exists; this does not exist for Arctic.

(4) Rossby waves ↳ due to closeness with land, Rossby waves meandering are more pronounced in Arctic region.

Diagram

[Sketch of meandering wave entering Arctic with 'warm air' arrows] Fig: Rossby wave

(5) Arctic sea is supposed to be over water; but antarctic region has underlying land mass.

Close · a way forward

It is a cause of concern that climate regulators like Arctic & Antarctic ice shelves are melting; CoP-26 Glasgow targets must be adhered.

How toppers approach this question, and more on its topic: open the question.

How do the melting of the Arctic ice and glaciers of the Antarctic differently affect the weather patterns and human activities on the Earth ? Explain.

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