Greenland is generally recognised as the largest island in the world when Australia is treated as a continent rather than an island. Greenland covers approximately 2.17 million square kilometres, making it substantially larger than every other island. It lies between the Arctic and North Atlantic oceans and is geographically part of North America, although it is an autonomous territory within the Kingdom of Denmark.
Most of Greenland is covered by the Greenland Ice Sheet, which is the second largest body of land ice on Earth after the Antarctic Ice Sheet. The island is therefore unusual because its enormous physical area is combined with an extremely small population and a landscape dominated by permanent ice, mountains, glaciers, fjords and polar environments.
Greenland's area is approximately 2,166,000 square kilometres, although precise figures can vary slightly depending on the geographical dataset and treatment of offshore islands. The island extends for roughly 2,670 kilometres from north to south and reaches a maximum width of about 1,050 kilometres. Its coastline is exceptionally long because of extensive fjord systems and irregular coastal geography. The interior is dominated by an ice sheet that reaches depths of several kilometres in places, while ice-free coastal regions contain most settlements and biological activity. The ice sheet strongly influences Greenland's climate, hydrology, landscape formation and global scientific importance.
The classification of Greenland as the world's largest island depends on a conventional geographical distinction between islands and continents. Australia has an area of approximately 7.7 million square kilometres and is physically surrounded by water, but it is conventionally classified as a continent rather than an island. Consequently, geographical lists of the largest islands normally exclude Australia. Greenland is therefore first in rankings that use the conventional continental classification. Antarctica is also excluded because it is a continent. This distinction illustrates that the concept of an island is not determined solely by whether land is surrounded by water; geographical classification, continental status and established scientific convention also matter.
Greenland's physical geography has been shaped extensively by glacial processes. During repeated Quaternary glaciations, moving ice eroded valleys, deepened basins and contributed to the formation of the dramatic fjords that characterise many coastal areas. The present Greenland Ice Sheet stores a very large quantity of freshwater and contains enough ice to produce a major global sea level contribution if completely lost, although complete loss would occur over timescales far longer than ordinary human planning horizons. Modern observations of Greenland's ice mass balance are therefore important to climate science and sea level research. Ice cores extracted from the Greenland Ice Sheet also provide evidence about past atmospheric composition and climate conditions.
Greenland's human geography is highly concentrated along the coast. The vast interior ice sheet is largely uninhabited, while settlements are located mainly on ice-free coastal land. Nuuk is the capital and largest settlement, and other communities include Sisimiut, Ilulissat, Qaqortoq and Aasiaat. The population is only around tens of thousands, producing an exceptionally low population density relative to the island's enormous area. Greenlandic culture reflects long Inuit traditions as well as centuries of interaction with Denmark and other North Atlantic societies. Greenlandic and Danish have important official and cultural roles, while Kalaallisut, the Greenlandic language, is central to national identity.
The island's economy has historically depended on fishing, hunting and related marine resources, with fisheries remaining particularly important. Other economic activities include tourism, transportation, mining exploration and public-sector services. Greenland possesses mineral resources, but extraction is affected by environmental conditions, infrastructure limitations, remoteness, costs and political considerations. Its location also gives it strategic significance because it lies between North America and Europe and near important Arctic routes. The surrounding waters support marine ecosystems containing species such as seals, whales, fish and seabirds, while terrestrial ecosystems include Arctic vegetation and animals adapted to severe cold.
Greenland is sometimes incorrectly described as the largest country or as an independent country. It is geographically the world's largest island, but politically it is an autonomous territory within the Kingdom of Denmark and is not a sovereign state. It has extensive self-government under the Greenland Self-Government Act, while Denmark retains responsibility for certain areas, including foreign affairs and defence, subject to the constitutional arrangement. The island's status therefore demonstrates the difference between geographical entities and political entities. Greenland's enormous area also does not imply a large population, because climate, ice coverage, terrain, infrastructure and remoteness impose substantial constraints on settlement.
The phrase largest island can have different meanings if the classification rules are changed. If continents are counted as islands, Australia would become the largest landmass commonly surrounded by ocean, but this is not the conventional geographical answer. If only permanently ice-free land were considered, Greenland's ranking would involve a different measurement because most of its surface is ice covered. Standard encyclopaedic geography therefore uses the established continental convention and identifies Greenland as the largest island. Greenland is consequently an important example for understanding the distinction between island, continent, territory, country, land area and ice-covered surface area.
