Explained | Arctic Ocean could be ice-free in summer by 2030s, say scientists

Source: The post is based on the article “Explained | Arctic Ocean could be ice-free in summer by 2030s, say scientists” published in The Hindu on 23rd June 2023

What is the News?

According to a study, the Arctic Ocean could be ice-free in summer by the 2030s, even if we do a good job of reducing emissions between now and then.

About Melting of Arctic Ice in Summer

The Arctic has been experiencing climate heating faster than any other part of the planet. 

The ice which remains at the end of summer is called multiyear sea ice and is considerably thicker than its seasonal counterpart. It acts as barrier to the transfer of both moisture and heat between the ocean and atmosphere. 

Over the past 40 years this multiyear sea ice in the Arctic has shrunk from around 7 million sq. km to 4 million. That is a loss equivalent to roughly the size of India or 12 UKs.

In other words, it’s a big signal, one of the most stark and dramatic signs of fundamental change to the climate system anywhere in the world.

What is the Blue Ocean Event?

Blue ocean event refers to a situation in which the Arctic Ocean becomes ice-free during the summer, with the sea ice area dropping below 1 million square kilometers.

This threshold is used mainly because older, thicker ice along parts of Canada and northern Greenland is expected to remain long after the rest of the Arctic Ocean is ice-free.

What are the consequences of Ice free Arctic in summer?

Arctic sea ice is an important component of the climate system. As it dramatically reduces the amount of sunlight absorbed by the ocean, removing this ice is predicted to further accelerate warming, through a process known as positive feedback. 

This, in turn, will make the Greenland ice sheet melt faster, which is already a major contributor to sea level rise.

The loss of sea ice in summer would also mean changes in atmospheric circulation and storm tracks and fundamental shifts in ocean biological activity.