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What is the News?
Arctic sea ice has appeared to have hit its annual maximum extent on February 25, 2022, after growing through the fall and winter. According to National Snow and Ice Data Centre(NSIDC), this year’s Arctic sea ice wintertime extent is the 10th-lowest in the satellite record.
Note: NSIDC is a United States information and referral centre in support of polar and cryospheric research.
What is Sea Ice?
Sea ice is essentially frozen ocean water. All stages of winter sea ice – formation, growth and melting – occur in the ocean, unlike icebergs, glaciers and ice shelves that originate on land.
Why is polar sea ice important?
Polar sea ice is important to maintain global temperatures. This is because sea ice reflects 80% of the sunlight that strikes its surface, thus keeping the polar regions cool.
Once the ice melts in the summer, the dark surface of the ocean is exposed, and it absorbs 90% of the sunlight that falls on it. This causes a rise in the temperature of the polar region.
Moreover, small temperature changes at the poles can lead to greater warming over time, making polar regions extremely sensitive to climate change. The loss of sea ice can accelerate global warming.
What is happening to the Arctic Sea Ice?
Sea ice waxes and wanes with the seasons every year.
In the Arctic, it reaches its maximum extent around March after growing through the colder months and shrinks to its minimum extent in September after melting through the warmer months. In the Southern Hemisphere, Antarctic sea ice follows an opposite cycle.
According to NASA, the maximum extents of the sea ice in the Arctic have declined at a pace of about 13% per decade since 1979 – when satellites began reliably tracking the data.
This is in sync with human global warming activities like the emission of carbon dioxide, deforestation and so on.
Source: This post is based on the article “Explained | Arctic sea ice peaked on February 25 this year. Why Is that important?” published in The Hindu on 1st April 2022.