TheArctic Circle, currently at roughly 66° north of theEquator, defines the boundary of theArctic seas and landsA political map showing land ownership within the Arctic regionArtificially coloured topographical map of the Arctic regionMODIS image of the Arctic
The Arctic region is a unique area among Earth's ecosystems. The cultures in the region and theArctic indigenous peoples have adapted to its cold and extreme conditions. Life in the Arctic includeszooplankton andphytoplankton, fish andmarine mammals, birds, land animals, plants, and human societies.[3] Arctic land is bordered by thesubarctic.
The word Arctic comes from theGreek wordἀρκτικόςarktikos "near the Bear, northern"[4] and from the wordἄρκτοςarktos meaning "bear" for either to theconstellation known asUrsa Major, the "Great Bear", which is prominent in the northern portion of thecelestial sphere,[5][6] or the constellationUrsa Minor, the "Little Bear", which contains thecelestial north pole (currently very nearPolaris, the current north Pole Star, or North Star).[7]
There are several definitions of what area is contained within the Arctic. The area can be defined as north of theArctic Circle (about 66° 34'N), the approximate southern limit of themidnight sun and thepolar night. Another definition of the Arctic, which is popular withecologists, is the region in theNorthern Hemisphere where the average temperature for the warmest month (July) is below 10 °C (50 °F); the northernmosttree line roughly follows theisotherm at the boundary of this region.[8][9]
Theclimate of the Arctic region is characterized by cold winters and cool summers. Its precipitation mostly comes in the form of snow and is low, with most of the area receiving less than 50 cm (20 in). High winds often stir up snow, creating the illusion of continuous snowfall. Average winter temperatures can go as low as −40 °C (−40 °F), and the coldest recorded temperature is approximately −68 °C (−90 °F). Coastal Arctic climates are moderated by oceanic influences, having generally warmer temperatures and heavier snowfalls than the colder and drier interior areas. The Arctic is affected by currentglobal warming, leading toclimate change in the Arctic, includingArctic sea ice decline, diminished ice in theGreenland ice sheet, andArctic methane emissions as thepermafrost thaws.[10][11] The melting of Greenland's ice sheet is linked topolar amplification.[12]
Due to the poleward migration of the planet's isotherms (about 56 km (35 mi) per decade during the past 30 years as a consequence of global warming), the Arctic region (as defined bytree line and temperature) is currently shrinking.[13] Perhaps the most alarming result of this is Arctic sea ice shrinkage. There is a large variance in predictions of Arcticsea ice loss, with models showing near-complete to complete loss in September from 2035 to sometime around 2067.[14][15]
Arctic vegetation is composed of plants such asdwarf shrubs,graminoids,herbs,lichens, andmosses, which all grow relatively close to the ground, formingtundra. An example of a dwarf shrub is thebearberry. As one moves northward, the amount of warmth available for plant growth decreases considerably. In the northernmost areas, plants are at their metabolic limits, and small differences in the total amount of summer warmth make large differences in the amount of energy available for maintenance, growth, and reproduction. Colder summer temperatures cause the size, abundance, productivity, and variety of plants to decrease. Trees cannot grow in the Arctic, but in its warmest parts, shrubs are common and can reach 2 m (6 ft 7 in) in height;sedges, mosses and lichens can form thick layers. In the coldest parts of the Arctic, much of the ground is bare;non-vascular plants such as lichens and mosses predominate, along with a few scattered grasses andforbs (like theArctic poppy).
There are copiousnatural resources in the Arctic (oil, gas, minerals, freshwater, fish, and, if the subarctic is included, forest) to which modern technology and theeconomic opening up of Russia have given significant new opportunities. The interest in the tourism industry is also on the increase.
The Arctic contains some of the last and most extensive continuouswilderness areas in the world, and its significance in preservingbiodiversity andgenotypes is considerable. The increasing presence of humans fragments vital habitats. The Arctic is particularly susceptible to the abrasion ofgroundcover and to the disturbance of the rare breeding grounds of the animals that are characteristic of the region. The Arctic also holds 1/5 of the Earth's water supply.[16]
During theCretaceous period, the Arctic still had seasonal snows, though only a light dusting and not enough to permanently hinder plant growth. Animals such as theChasmosaurus,Hypacrosaurus,Troodon, andEdmontosaurus may have all migrated north to take advantage of the summer growing season, and migrated south to warmer climes when winter came. A similar situation may also have been found amongstdinosaurs that lived inAntarctic regions, such as theMuttaburrasaurus of Australia.
However, others claim that dinosaurs lived year-round at very high latitudes, such as near theColville River, which is now at about 70° N but at the time (70 million years ago) was 10° further north.[17]
The Dorset /Thule culture transition dates around the ninth–10th centuries CE. Scientists theorize that there may have been cross-contact between the two cultures with the sharing of technology, such as fashioning harpoon heads, or the Thule may have found Dorset remnants and adapted their ways with the predecessor culture.[22] The evidence suggested that Inuit descend from theBirnirk of Siberia, through the Thule cultureexpanded into northern Canada and Greenland, where they genetically and culturally completely replaced the IndigenousDorset people sometime after 1300 CE.[23] The question of why the Dorset disappeared so completely has led some to suggest that Thule invaders wiped out the Dorset people in "an example of prehistoric genocide."[24]
By 1300 CE, theInuit, present-day Arctic inhabitants and descendants of Thule culture, had settled in west Greenland and moved into east Greenland over the following century (Inughuit,Kalaallit andTunumiit are modern Greenlandic Inuit groups descended from Thule). Over time, the Inuit have migrated throughout the Arctic regions of Eastern Russia, the United States, Canada, and Greenland.[25]
Research in the Arctic has long been a collaborative international effort, evidenced by theInternational Polar Year. TheInternational Arctic Science Committee, hundreds of scientists and specialists of theArctic Council, and the Barents Euro-Arctic Council are more examples of collaborative international Arctic research.[30]
While there are several ongoingterritorial claims in the Arctic, no country owns the geographicNorth Pole or the region of the Arctic Ocean surrounding it. The surrounding six Arctic states that border the Arctic Ocean—Canada, the Kingdom of Denmark (with Greenland), Iceland, Norway, Russia, and the United States—are limited to a 200nautical miles (370 km; 230 mi)exclusive economic zone (EEZ) off their coasts. Two Arctic states (Finland and Sweden) do not have direct access to the Arctic Ocean.
Upon ratification of theUnited Nations Convention on the Law of the Sea, a country has ten years to make claims to anextended continental shelf beyond its 200 nautical mile zone.[26][31] Due to this, Norway (which ratified the convention in 1996),[32] Russia (ratified in 1997),[32] Canada (ratified in 2003)[32] and the Kingdom of Denmark (ratified in 2004)[32] launched projects to establish claims that certain sectors of the Arctic seabed should belong to their territories.
On 2 August 2007, two Russianbathyscaphes,MIR-1 and MIR-2, for the first time in history descended to the Arcticseabed beneath the North Pole and placed there aRussian flag made of rust-prooftitanium alloy. The flag-placing, duringArktika 2007, generated commentary on and concern for a race for control of the Arctic's vast hydrocarbon resources.[33]
Foreign ministers and other officials representing Canada, the Kingdom of Denmark, Norway, Russia, and the United States met inIlulissat, Greenland on 28 May 2008 at theArctic Ocean Conference and announced theIlulissat Declaration,[34][35] blocking any "new comprehensive international legal regime to govern the Arctic Ocean," and pledging "the orderly settlement of any possible overlapping claims."[26][36]
The Russian Federation is alsoclaiming a large swath of seabed along the Lomonosov Ridge but, unlike Denmark, confined its claim to its side of the Arctic region. In August 2015, Russia made a supplementary submission for the expansion of the external borders of its continental shelf in theArctic Ocean, asserting that the eastern part of the Lomonosov Ridge and theMendeleyev Ridge is an extension of theEurasian continent. In August 2016, theUN Commission on the Limits of the Continental Shelf began to consider Russia's submission.[38]
Canada claims theNorthwest Passage as part of itsinternal waters belonging to Canada, while the United States and most maritime nations[39] regards it as aninternational strait, which means that foreign vessels have right of transit passage.[40]
Since 1937, the larger portion of the Asian-side Arctic region has been extensively explored by Soviet and Russian creweddrifting ice stations. Between 1937 and 1991, 88 international polar crews established and occupied scientific settlements on thedrift ice and were carried thousands of kilometers by the ice flow.[41]
The Arctic is comparatively clean, although there are certain ecologically difficultlocalized pollution problems that present a serious threat to people's health living around these pollution sources. Due to the prevailing worldwide sea and air currents, the Arctic area is the fallout region for long-range transportpollutants, and in some places, the concentrations exceed the levels of densely populated urban areas. An example of this is the phenomenon ofArctic haze, which is commonly blamed on long-range pollutants. Another example is with thebioaccumulation of PCBs (polychlorinated biphenyls) in Arctic wildlife and people.
There have been many proposals to preserve the Arctic over the years. Most recently a group of states[clarification needed] at theUnited Nations Conference on Sustainable Development, on 21 June 2012, proposed protecting the Arctic, similar to theAntarctic Treaty System. The initial focus of the campaign will be a UN resolution creating a global sanctuary around the pole, and a ban on oil drilling and unsustainable fishing in the Arctic.[42]
The Arctic has climate change rates that are amongst the highest in the world. Due to the major impacts to the region from climate change the near climate future of the region will be extremely different under all scenarios of warming.[43]
The Arctic region is especially vulnerable to the effects of anyclimate change, as has become apparent with the reduction of sea ice in recent years.Climate models predict much greaterclimate change in the Arctic than the global average,[47] resulting in significant international attention to the region. In particular, there are concerns that Arctic shrinkage, a consequence of melting glaciers and other ice in Greenland, could soon contribute to a substantial rise in sea levels worldwide.[48]
The current Arctic warming is leading to ancient carbon being released from thawingpermafrost, leading tomethane andcarbon dioxide production by micro-organisms.[49][50] Release of methane and carbon dioxide stored in permafrost could cause abrupt and severe global warming,[51] as they are potentgreenhouse gases.[52]
The shrinking Arctic: Parts of Norway inside the Arctic Circle has a temperate climate with the 1991–2020 normals, such asSkrova nearSvolvær with mean annual temperature of 6 °C (43 °F), four months above 10°C and no month below 0 °C (32 °F).[53]
Climate change is also predicted to have a large impact on tundra vegetation, causing an increase of shrubs,[54] and having a negative impact on bryophytes and lichens.[55]
Apart from concerns regarding the detrimental effects of warming in the Arctic, some potential opportunities have gained attention. The melting of the ice is making theNorthwest Passage, shipping routes through the northernmost latitudes, more navigable, raising the possibility that the Arctic region will become a primetrade route.[56] One harbinger of the opening navigability of the Arctic took place in the summer of 2016 when theCrystal Serenity successfully navigated the Northwest Passage, a first for a large cruise ship.[57]
In addition, it is believed that the Arctic seabed may contain substantialoil fields which may become accessible if the ice covering them melts.[58] These factors have led to recent international debates as to which nations can claim sovereignty or ownership over the waters of the Arctic.[59][60][61][62]
^The word was originally pronounced without the/k/ sound, but the pronunciation with the k sound is nowadays very common. The "c" was added to the spelling for etymological reasons[1][2] and then began to be pronounced.
^King, Lorenz (1992). "Polarregionen, vom Neuland zum wissenschaftlichen Brennpunkt" [Polar regions, from uncharted territory to scientific focus].Giessener Diskurse: Wissenschaft und Neues Weltbild (in German).6/7:231–256.ISBN3-927835-25-0.
^Galera, L. A., Eckhardt, T., Beer, C., Pfeiffer, E.-M., & Knoblauch, C. (2023). "Ratio of in situ CO2 to CH4 production and its environmental controls in polygonal tundra soils of Samoylov Island, Northeastern Siberia".Journal of Geophysical Research: Biogeosciences, 128, e2022JG006956.https://doi.org/10.1029/2022JG006956Archived 30 June 2023 at theWayback Machine
^Alatalo, Juha M.; Jägerbrand, Annika K.; Molau, Ulf (1 November 2015). "Testing reliability of short-term responses to predict longer-term responses of bryophytes and lichens to environmental change".Ecological Indicators.58:77–85.doi:10.1016/j.ecolind.2015.05.050.
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