A report by the World Economic Forum (WEF) has pointed out that with change in climatic conditions, multi-year ice is depleting.
In the last four decades, the multi-year ice around the Arctic has shrunk to half.
Arctic sea ice, without a doubt, plays an important role in maintaining the Earth’s energy balance. As the area is covered with snow for most of the year, it reflects around 80 per cent of the solar radiation and sends it back to outer space. Further, the oceans have the capacity of absorbing 90 per cent of incident solar radiation. Therefore, the amount of heat absorbed by the planet and the rate of absorbing is dependent on how much sea ice cover is there. Now the world has a bigger problem on its hands as these ice covers are depleting.
A report by the World Economic Forum (WEF) has pointed out that with change in climatic conditions, multi-year ice is depleting. It is to note that every year, a thin layer of the ocean water freezes and forms sea ice. This sea ice melts during summer, but some part of it does not thaw due to resilience. This part is known as multi-year ice. The report said that multi-year ice at the Arctic is now under threat as it has been declining at twice the rate (possibly more) than the rest of the world.
In the last four decades, the multi-year ice around the Arctic has shrunk to half. This has alarmed scientists as there is a possibility of an ice-free Arctic Ocean during summers in the coming decades. An exceptional summer heatwave in the Russian Arctic has made the situation more worrisome this year. In the Laptev Sea, which is located north of the Siberian coast, reported a record low in 2020. In October, new ice was formed due to the heat wave and this has delayed the regrowth of sea ice significantly. Surprisingly, this part of the ocean is considered “a factory for new sea ice in autumn and winter” as the temperature dips to minus degrees. However, this was not the case this year.
This has indicated that the whole Arctic Ocean is heading for drastic conditions in near the future where the ocean can be ice-free. WEF has defined this as a condition where less than one million square kilometres of ice cover is formed. Shockingly, this has come down from 8 million square kilometres of ice covers formed around 40 years ago. With this, a record delay in ice formation has been observed and this rapidly changing Arctic sea has been stated as a global cause for concern. The quick thawing permafrost is also responsible for methane release in the environment. Methane is a greenhouse gas known for 84 times more potency when compared to Carbon dioxide that has been measured over 20 years.
Meanwhile, the Greenland Ice Sheet is also melting and contributing to a rise in sea levels. The largest ice mass in the northern hemisphere has the capacity to raise global sea level by 7.4 metres.