The Arctic Ecosystem: Top of the World, Fragile and Frozen

Definition & Boundaries

The Arctic ecosystem encompasses the Arctic Ocean and the northernmost lands of North America (Alaska, Canada), Europe (Nordic, Russia), and Asia (Siberia) — roughly north of the Arctic Circle (66°34′N) or the 10 °C July isotherm (treeline).

Key Components

• Sea ice: Seasonal (14M km² winter → 4M km² summer); habitat for algae, polar bears, seals.
• Tundra: Permafrost, mosses, lichens, dwarf shrubs; caribou, lemmings, Arctic fox.
• Freshwater: Lakes, rivers, wetlands — breeding grounds for migratory birds.
• Marine food web: Phytoplankton → copepods → Arctic cod → seals → polar bears; whales (bowhead, narwhal, beluga).

Climate Sensitivity

• Warming 3–4× global average ("Arctic amplification").
• Sea ice loss → albedo feedback → more warming.
• Permafrost thaw → carbon/methane release, infrastructure damage.
• Species shifts: boreal encroachment, phenology mismatch.

Governance

Arctic Council (8 states + 6 Indigenous permanent participants) — cooperation on science, search/rescue, pollution. UNCLOS governs ocean rights.