Key Highlights
- Greenland, spanning over 2 million km², remains the world’s biggest island.
- The top five islands—New Guinea, Borneo, Madagascar, and Baffin—occupy the next largest lands.
- These islands encompass a spectrum of climates, from Arctic tundra to equatorial rainforests.
- Indigenous communities, especially the Inuit in Greenland, shape local governance through home rule.
- Each island hosts unique biodiversity, including many endemic mammals, birds, and plant species.
Detailed Insights
Greenland’s massive ice sheet, covering four‑fifths of the land, is the second largest on Earth after Antarctica, maintaining an average thickness of about 1 500 m. The island’s climate ranges from sub‑arctic in the south to polar in the north, with temperatures in winter falling below ‑30 °F (‑34 °C) in the far north. Though part of Denmark, Greenland enjoys a self‑governance framework that allows local management of natural resources and public services.
New Guinea, the world’s second largest island, bears the world’s highest rainfall—a yearly total that can exceed 300 inches—and consequently hosts dense, wet tropical forests. Its remoteness and rugged terrain have kept its population density relatively low but its biodiversity exceptionally rich, with several species found nowhere else on Earth.
Borneo, located across Indonesia, Malaysia, and Brunei, harbors one of the oldest rainforests in the world, sustaining colossal flora such as the Rafflesia arnoldii, the planet’s largest flower, as well as a vast array of fauna that includes orangutans and clouded leopards. The island’s ecological importance is matched by its role as a critical carbon sink.
Madagascar, sitting about 250 miles off Madagascar’s coast, stands out for its endemic wildlife—nearly 40 species of lemur and over 800 butterfly taxa. Its isolation has fostered an exceptional level of endemism across all kingdoms of life.
Baffin Island, the fifth largest, remains largely uninhabited except for a handful of coastal settlements. It holds particular geological significance and is an important site for studying Arctic ecosystems.
Key Concepts
- Island: Landmass completely surrounded by water, often defined by its proximity to a continental shelf or separate from mainland via water.
- Ice sheet: A vast, continuous expanse of glacial ice covering more than one percent of a continent’s surface, characterized by slow flow and thickness often exceeding 1 000 m.
- Home rule: A political arrangement granting an entity jurisdiction over internal affairs while remaining part of a sovereign state.
- Arctic climate: A climatic zone marked by long, cold winters, brief, cool summers, and permafrost, typically found north of the Arctic Circle.
- Biodiversity: The variety and variability of life forms within a given ecosystem, encompassing genetic, species, and ecosystem levels.