Arctic Amplification

Why in news?

• Finnish researchers have found that the Arctic is heating four times faster than the rest of the planet.

More about the news:

• The warming is concentrated in the Eurasian part of the Arctic, where the Barents Sea north of Russia and Norway is warming at an alarming rate — seven times faster than the global average.
• Other studies indicate that the Arctic amplification is four times the global rate.

About Arctic Amplification:

• Global warming has hastened due to anthropogenic forces or human activities since pre-industrial times and has increased the planet’s average temperature by 1.1 degrees Celsius.
• While changes are witnessed across the planet, any change in the surface air temperature and the net radiation balance tend to produce larger changes at the north and south poles.
• This phenomenon is known as polar amplification; these changes are more pronounced at the northern latitudes and are known as the Arctic amplification.

Causes of Arctic Amplification:

• Among the many global warming-driven causes for this amplification, the ice-albedo feedback, lapse rate feedback, water vapour feedback and ocean heat transport are the primary causes.
• Sea ice and snow have high albedo (measure of reflectivity of the surface), implying that they are capable of reflecting most of the solar radiation as opposed to water and land.
• In the Arctic’s case, 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 i.e. lapse rate decreases with warming.
• Studies show that the ice-albedo feedback and the lapse rate feedback are responsible for 40% and 15% of polar amplification respectively.

Impacts:

• If the sheet melts completely, the sea level would rise by seven metres, capable of subsuming island countries and major coastal cities.
• The warming of the Arctic Ocean and the seas in the region, the acidification of water, changes in the salinity levels, are impacting the biodiversity, including the marine species and the dependent species.
• The warming is also increasing the incidence of rainfall which is affecting the availability and accessibility of lichens to the reindeer.
• The Arctic amplification is causing widespread starvation and death among the Arctic fauna.
• The permafrost in the Arctic is thawing and in turn releasing carbon and methane which are among the major greenhouse gases responsible for global warming.
• Experts fear that the thaw and the melt will also release the long-dormant bacteria and viruses that were trapped in the permafrost and can potentially give rise to diseases.

Impacts on India:

• In recent years, 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 the heavy reliance on rainfall for water and food security.
• A study says that reduced sea ice in the Barents-Kara sea region can lead to extreme rainfall events in the latter half of the monsoons — in September and October.
• The changes in the atmospheric circulation due to diminishing sea ice combined with the warm temperatures in the Arabian Sea contribute to enhanced moisture and drive extreme rainfall events.

Add ons:

• In 2014, India deployed IndARC, India’s first moored-underwater observatory in the Kongsfjorden fjord, Svalbard.
• It aims to monitor the impact of the changes in the Arctic Ocean on tropical processes such as the monsoons.

PRACTICE QUESTION:

Consider the following statements:

1. Any change in the net radiation balance tends to produce a larger change in temperature near the poles than in the planetary average

2. Diminishing sea ice in the Arctic combined with the warm temperatures in the Arabian Sea contribute to extreme rainfall events in Indian sub-continent

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer