What is happening to Arctic sea ice?

Subject: Geography

Section: Physical geography

Context:

A recent study says that the loss of Arctic sea ice is inevitable in the decades ahead, even if the world somehow gets its act together and sharply reduces carbon emissions.

Why is the Arctic sea ice important?

It influences the global climate and the rise and fall in Arctic sea temperatures.
It reflects more sunlight back to space than liquid water, thus playing a vital role in keeping polar regions cool and maintaining the earth’s energy balance.
Sea ice also keeps the air cool by forming a barrier between the cold air above and the relatively warmer water below. As the amount of sea ice decreases, the Arctic region’s cooling effect is reduced, and this may initiate a ‘feedback loop’ whereby ocean warming caused by more absorption of solar energy leads to an even greater loss of sea ice and further warming.
Impact of changes in sea ice:
- Positive impact: Presents “commercial and economic opportunities” with the opening up of shipping lanes and increased access to natural resources in the Arctic region.
- Negative impact: It can affect biodiversity and impact mammals such as polar bears and walruses, which rely on the presence of sea ice for hunting, breeding, and migrating.
  - It also affects the traditional subsistence hunting lifestyle of indigenous Arctic populations such as the Yup’ik, Iñupiat, and Inuit

What does the new study say?

The world will see its first ‘sea-ice-free summer’ before 2050.
The global emissions will drive temperatures to beyond 4.5°C making the Arctic ice-free by 2081-2100.
There is no scenario under which the Arctic sea ice can be saved in summer.
Moreover, if drastic reductions in emissions aren’t undertaken, we could very well be seeing the first such summer in the 2030s.

Consequences:

The diminished sea ice while warming the Arctic also leads to a weakening of the polar jet streams, which are currents of air that form when warm and cold air meet.
This weakening has been linked to rising temperatures and heatwaves in Europe as well as unseasonal showers in northwest India.
While the ice-free summer may be inevitable, reducing carbon emissions might mean being better able to adapt to climate ‘tipping points.’