A recent study says that the loss of Arctic sea ice is inevitable in the decades ahead, even if the world sharply reduces carbon emissions.
What is Arctic sea ice?
They are the massive sheets of ice that pad the Arctic region.
During winter, the sea ice envelops most of the Arctic Ocean and in summer, due to longer periods of exposure to sunlight, a portion of it melts.
Sea ice normally melts and is at its thinnest and most sparse in mid-September.
With the onset of winter and dipping temperatures, the ice reaches its zenith in March.
What is happening to Arctic sea ice?
The Arctic sea ice is decreasing as acknowledged in several reports of the Intergovernmental Panel on Climate Change (IPCC).
Ice-free arctic - If the global emissions drive temperature beyond 4.5°C, then the Arctic is ice-free by 2081-2100.
Under this assumption, the world will see its first ‘sea-ice free summer’ before 2050.
Polar jet streams - They are currents of air that form when warm and cold air meet.
The diminished sea ice while warming the Arctic also leads to a weakening of the polar jet streams.
Western disturbances - This weakening has been linked to rising temperatures and heatwaves in Europe as well as unseasonal showers in northwest India.
The rate of arctic ice loss has been nearly 13% every year, ever since satellites began to monitor arctic.
What does the new study say?
As much as 90% of the ice-melting was due to human-instigated, or anthropogenic factors and the rest of it (10%) is caused by natural variability.
The new study corrected for the existing climate models and the ice-free summer is inevitable.
But reducing carbon emissions might better able to adapt to climate ‘tipping points.’
Above 4.5°C - It turned out that there were also likely to be ice-free Augusts and Octobers by 2080 in the emission scenarios where temperatures rose above 4.5°C.
Below 2°C - Even if the temperature-rise was restricted to say 1.5°C or 2°C, as envisaged in the Paris Agreement, there is no scenario under which the Arctic sea ice can be saved in summer.
Why is the Arctic sea ice important?
Arctic sea ice play a major role in influencing global climate and the rise and fall in Arctic sea temperatures.
Albedo effect - Sea ice is light-coloured and therefore has more albedo.
Thus sea ice plays a vital role in keeping Polar Regions cool and maintaining the earth’s energy balance.
Natural barrier - Sea ice also keeps the air cool by forming a barrier between the cold air above and the relatively warmer water below.
Feedback Loop - As the amount of sea ice decreases, the Arctic region’s cooling effect is reduced leading to ‘feedback loop’.
More absorption of solar energy causes ocean warming, which leads to more loss of sea ice and further warming.
Biodiversity - Changes in sea ice can affect biodiversity and impact mammals such as polar bears and walruses.
These mammals rely on the presence of sea ice for hunting, breeding, and migrating.
Arctic lifestyle - The reduction in ice cover also affects the traditional hunting lifestyle of indigenous Arctic populations such as the Yup’ik, Iñupiat, and Inuit.
New pathways - Reduced ice can open commercial and economic opportunities provoking global competition.
Reduced ice opens up shipping lanes and increases access to natural resources in the Arctic region.
