Tundra Arctic Ecosystem

The Arctic tundra — the treeless, permanently frozen landscape covering approximately 10 million km² in the high latitudes of Russia, Canada, Alaska, and Greenland — is the world's fastest-warming ecosystem, heating at 2-3x the global average rate (Arctic amplification). The tundra's defining feature is permafrost — permanently frozen soil extending up to 1,500m deep — which contains vast stores of organic carbon accumulated over thousands of years. Arctic warming threatens a catastrophic feedback loop: as permafrost thaws, it releases ancient organic carbon as CO2 and methane (a greenhouse gas 80x more potent than CO2 over 20 years) — which causes more warming, which causes more thawing. This 'permafrost carbon bomb' contains an estimated 1.5 trillion tonnes of carbon — twice the amount currently in the atmosphere. Arctic sea ice area has declined 40% since satellite monitoring began in 1979; September sea ice may be completely absent within decades, eliminating polar bear habitat and changing weather patterns for North America and Europe (through jet stream disruption). The tundra supports reindeer/caribou (the largest land migration in the Northern Hemisphere), Arctic foxes, lemmings, and migratory birds.