ARCTIC WARMING

Source-the Hindu

2021 was the Arctic’s 7^th warmest year on record.
The Arctic is heating 4times faster than the rest of the planet.
The warming is more concentrated in the Eurasian part of the Arctic, where the Barents Sea north of Russia & Norway is warming at an alarming rate-7 times faster than the global average.
Earlier studies proved that the Arctic is warming 2 or 3 times faster, recent studies show that the region is fast changing which cannot be predicted accurately.

Global warming, the long-term heating of the earth’s surface, hastened due to anthropogenic forces since pre-industrial times & increased the planet’s average temperature by 1.1°.
The changes are witnessed across the planet and the net radiation balance tends to produce larger changes at the north & south poles.
This phenomenon is known as polar amplification, these changes are more pronounced at the northern latitudes & known as the Arctic amplification.
Among many global warming-driven causes, the ice-albedo feedback, ocean heat transport, lapse rate feedback, and water vapour feedback are the primary causes.
Sea ice and snow have a high albedo(a measure of the reflectivity of the surface), implying that they are capable of reflecting most of the solar radiation as opposed to water & land.
Global warming is resulting in diminishing sea ice.
As the sea ice melts, the Arctic ocean will be more capable of absorbing solar radiation, thereby driving the amplification.
The rate at which the temperature drops with elevation decreases with warming.
Studies show that the ice-albedo feedback & the lapse rate feedback are responsible for 40% & 15% of polar amplification respectively.

The extent of Arctic amplification is debated, as studies show various rates of amplification against the global rate.
Studies show that the Arctic was warming at twice the global rate before the beginning of the 21^st“Special Report on the Ocean & Cryosphere in a Challenging Climate” in 2019, said that the Arctic surface air temperature has likely increased by more than double the global average over the last two decades.
The Arctic Monitoring & Assessment Program(AMAP) warned that the Arctic has warmed 3times quicker than the planet.
The chance of the sea ice completely disappearing in summer is 10 times greater if the planet is warmer by 2°C above the pre-industrial levels.
The average annual temperature in the region increased by 3.1^°C compared to the 1^°C for the planet.
Recent studies show that the mean Arctic amplification saw steep changes in 1986 & 1999, when the ratio reached 4.0, implying 4 times faster heating than the rest of the planet.

The causes & consequences of Arctic amplification are cyclical.
The Greenland ice sheet is melting at an alarming rate & the rate of accumulation of sea ice was low since 2000.
The Greenland ice sheet saw a sharp spike in the rate & extent of melting in July this year.
The unusual summer temperature resulted in a melt of 6 billion tonnes of ice sheet per day, amounting to 18 billion tonnes in 3 days.
Greenland ice sheet holds the 2^nd largest amount of ice, after Antarctica.
In 2019, this was the single biggest cause of the rise in the sea level, about 1.5 meters.
If the sheet melts completely, the sea level would rise by 7 meters, capable of subsuming island countries & major coastal cities.
Warming of the Arctic Ocean, seas in the region, acidification of water, and changes in the salinity levels are impacting biodiversity.
The warming is increasing the incidence of rainfall which is affecting the availability & accessibility of lichens % of the reindeer.
The Arctic amplification is causing widespread starvation & death among the Arctic fauna.
The permafrost in the Arctic is releasing carbon & methane which are among the major greenhouse gases responsible for global warming.

Scientists have pondered over the impact the changing Arctic can have on the monsoons in the subcontinent.
The link between the two is growing in importance due to the extreme weather events the country faces, and heavy reliance on rainfall for water & food security.
The reduced sea ice in the Barents-Kara sea region can lead to extreme rainfall events in the latter half of the monsoons.
The changes in the atmospheric circulation due to diminishing sea ice combined with the warm temperature in the Arabian Sea contribute to enhanced moisture & drive extreme rainfall events.
India deployed IndARC, India’s first moored-underwater observatory in Svalbard, to monitor the impact of the changes in the Arctic Ocean on tropical processes like monsoons.

According to the World Meteorological Organization’s report, the sea level along the Indian coast is rising faster than the global average rate.
The primary reason for this rise is the melting of sea ice in the polar regions, especially the Arctic.

Share to Social