The Arctic ocean is the world’s smallest ocean (covering 6.1 million square miles). It is the Earth’s northernmost body of water and encircles the North Pole.
The Arctic ocean is belatedly getting the undivided attention of all scientists as it is warming quicker than anywhere else on Earth.
The geographical jurisdiction of six countries – namely Canada, Greenland, Iceland, Norway, Russia and the U.S. extends into the Arctic ocean.
Climate change in Arctic ocean
Global warming in Arctic ocean (or climate change in Arctic ocean) includes rising air / water temperatures, sea ice loss and melting of the Greenland ice sheet.
Also, because of a cold temperature anomaly, there are other effects such as increased input of freshwater, ocean circulation changes and ocean acidification.
Other indirect impacts could lead to a greater frequency of extreme weather events such as drought, fires and flooding, biological, ecological, biological migrations / extinctions, displacement, stress on natural resources apart from human health and life itself.
Rising temperatures in Arctic ocean
During 1995 – 2005, the warmest decade since at least 17th century temperatures were 2°C (3.6°F) above 1951 – 1990 average. Temperatures in the region haven’t been as high as they presently are since some 44,000 years ago and possibly even as long as 120,000 years ago.
The Arctic temperature has increased by 2.3°C compared to the 1970s.
Ice and snow, being shiny in nature (surface reflectivity), reflect much of the sun’s energy into space. With the loss of ice and snow, bare rocks and dark ocean waters absorb more of the sun’s energy, making it even warmer. This is known as the Albedo effect.
Thus, sea ice loss may could mean a tipping point in climate change in Arctic ocean, when uncontrollable climate change starts.
But oddly, on this subject, scientists are not in agreement on the matter amongst the own fraternity!
Climate change in Arctic: Arctic sea ice decline
Sea ice is currently in decline in area, extent, and volume and will cease to exist during the 21st century.
When it comes to climate change in Arctic ocean, the decline in area, extent, and volume of sea ice is significant and the September sea ice cover was only 30% compared to 1980. Summers in the Arctic end in September. Not entire sea ice melts in summers – or at least that used to be the case. Multi-year ice could undergo years of melting and growing, getting thicker and more structurally complex. But, over the last 50 years, multi-year ice has become scarce. Compared to a one-third of the Arctic’s ice cover more than four years old in the 1980s – today, there is no multi-layer ice.
Due to climate change in Artic ocean, the sea ice is melting rapidly and a 2016 study determined by 2040, the Arctic ocean will be ice-free for ships to sail unhindered to the North Pole.
During the last century, global sea levels have risen 4-8 inches. Melting Arctic ice will lead to even greater sea level rise, which according to some experts may be as high as 23 feet by 2100.
Melting of the Greenland ice sheet
Climate models suggest a sea level increase of about 5 cm. (2 in.) from melting of the Greenland ice sheet in the 21st century.
In 2018, due to climate change in Arctic ocean, part of Greenland ice sheet became sea ice free for the first time in millions of years and the Arctic ocean experienced a record setting second-worst sea ice decline.
Arctic amplification and thawing of permafrost
To repeat, when the white sea ice melts in summer, areas of dark open water are exposed which can absorb more heat from the sun. That extra heat then helps melt even more ice.
Thawing (melting) of Arctic permafrost (grounds that remain frozen for at least two years) results in plant and animal decay releasing large amounts of carbon. Some two-thirds of the released carbon escapes to the atmosphere as carbon dioxide.
Enough evidence has been collected by experts that such positive feedbacks are present in the Arctic. The phenomena goes by the scientific name Arctic amplification.
CO2 in the atmosphere has resulted in increased concentration of CO2 in oceans, leading to increased acidity (lower pH) of water – known as ocean acidification.
Black carbon deposits from marine engines reduce the albedo when deposited on snow or ice, and fasten effect of the melting of snow / sea ice.
Climate change in Arctic ocean: Ecology and Biodiversity
Plankton (algae and bacteria) is at the bottom of the Arctic food chain. They convert CO2 from the atmosphere into organic form which feed all sea life from small fish to large bowhead whales. In the sea ice reside the plankton-eating zooplankton and in the deep ocean Arctic reside corals, sea anemones and sponges.
The northward shift of the subarctic climate zone allows more climate adaptable animals to move into the far north, thus replacing species that are accustomed to the pure Arctic climate.
Studies have also confirmed that over the next 50 years, much of the polar bear habitat will be wiped out as the floating Arctic sea ice will continue its rapid shrinkage. The shrinkage of sea ice would also lessen the seal hunting season due to late formation and early thaw of pack ice.
More woody plants, more precipitation, and warmer temperatures change the ecological balance and threatens the survival of caribou, fish (which are temperature sensitive and moving northwards), small Artic fox, reindeer, musk oxen and walruses. Also at threat are narwhals and bowhead whales from killers whales.
The Arctic animals also have to contend with exposure to human-caused sound, entanglement in fishing nets or lines, pollution and ship strikes.
Social impacts on indigenous population
About 4 million (40 lakhs) people stay in the Arctic, most of them indigenous people for whom the Arctic is their ancestral land.
They live off the land, by engaging themselves in activities such as fishing, sealing and whaling.
Climate change by burning of greenhouse gases in other places in the world is having a profound effect on Arctic people and other communities elsewhere in the world.
For the Inuit and other small communities, hunting – the major way to survive is forever being changed by the increasing temperatures as the decrease in sea ice will cause some animal populations to decline or become extinct.
Fish and whale are important food sources and in 2018, it was formally recognized that as climate change in Arctic was leading to rampant fishing. 10 countries also agreed to a moratorium on further fishing until such time scientists could determine if sustainable fishing was possible in the Arctic.
Transportation routes and land pipelines are getting disrupted by melting of sea ice. The usual mode of transportation for many Arctic communities is frozen roadways is being challenged by a changing landscape and weather unpredictability.
The Transpolar Sea Route (or Trans-Arctic Route) is becoming an Arctic shipping lane of the future from the Atlantic Ocean to the Pacific Ocean traversing the centre of the Arctic Ocean. Compared to the Northeast Passage (that includes Northern Sea Route) and the North-West Passage, its navigational advantage is that mostly avoids the territorial waters of Arctic states and lies in international high seas.
For a host of reasons, many governments and the private industry are increasing their stake in the Arctic.
Shipping companies stand to gain from the shortened distance of northern routes. Governments stand to gain from access to valuable minerals and offshore oil and gas. Additionally, there will be commercial fishing, military operations and tourism.
The economic lure of the Arctic for those without scruples or qualms about climate change in Arctic ocean is so strong that they will go to any lengths to dominate the Arctic ocean.
Russia and Norway have expanded their military presence for an ice-free Arctic. Russia, on last count, had deployed a third nuclear icebreaker ship in the Arctic ocean. China too has displayed its interest by sending a submarine and participating in Russia-led forums. Canada and the US already have a military presence in the Arctic.
Whoever controls change in the Artic will enjoy good fortune and power.