Context: A new study published in the journal Earth’s Future, has put a timeline to an impending disaster of shrinkage of summer sea ice in the Arctic.
About the study
The research looked at two scenarios

Optimistic scenario: (if carbon emissions are brought in check)

• Some summer ice could persist indefinitely.

Pessimistic: (if emissions continue as they are)

• Summer ice would disappear by the end of the century.
• Under the low-emissions scenario, Ice from even the central Arctic will wane by mid-century, and will no longer endure through the year.

Findings of the study

• Shrinkage of summer sea ice in the Arctic has long been a concern, especially for species that depend on it for survival.
• If carbon emissions continue at current levels, summer ice will disappear by 2100 and, along with it, creatures such as seals and polar bears.
• In winter, most of the Arctic Ocean surface freezes, and scientists expect this to continue for the foreseeable future, even as climate warms.
• In summer, when some of the ice melts, winds and currents carry it for great distances– some of it into the North Atlantic, but much of it into the Arctic’s farthest-north coasts, along Greenland and the Canadian islands.
• This results in a rich marine ecosystem. On the Arctic ice, algae bloom.
• These feed tiny animals, which in turn feed fish, which in turn feed seals, which feed polar bears at the top of the chain.
• The irregular topography also helps create lairs for seals, and ice caves for polar bears during the winter.
• But with a warming climate, summer sea ice has been shrinking fast, and now consistently spans less than half the area it did in the early 1980s.

Implications

• Under the low-emissions scenario, at least some seals, bears and other creatures may survive.
• These species currently exist under similar summer conditions along western Alaska and parts of Hudson Bay.
• Under the higher-emissions scenario, by 2100, even the locally formed ice will disappear in summer and with that there will be no ice-dependent ecosystems.
• If the year-round ice goes away, entire ice-dependent ecosystems will collapse, and something new will begin.