Arctic Tundra: Transitioning to a Carbon Source

News: The Arctic Tundra has shifted from being a carbon sink to a carbon emitter, as confirmed by a recent analysis in the National Oceanic and Atmospheric Administration’s (NOAA) Arctic Report Card.

About Arctic Tundra

• The Arctic Tundra is a unique biome located in the northernmost parts of Earth, primarily north of the Arctic Circle.
• It is characterized by extreme cold, treeless landscapes, and a harsh climate.
• Characteristics of the Arctic Tundra:
  • Permafrost: It refers to permanently frozen soil beneath the surface, starting within 1 meter of the ground. In summer, only the uppermost layer of permafrost thaws, while deeper layers remain frozen.
    • Effect: Limits plant root growth and prevents the growth of trees, resulting in a treeless landscape.
  • Soil composition: The tundra soil is nutrient-poor and rocky, due to slow decomposition caused by cold temperatures. Organic matter (like sphagnum moss) accumulates as peat and humus, forming a significant carbon sink.
  • Climate:
    • Temperatures range from 15.5°C in summer to -60°C in winter, with mean temperatures below 0°C for 6–10 months.
    • Low annual precipitation (150–250 mm) but minimal evaporation.
    • Features 24-hour sunlight in summer and 24-hour darkness in winter.
  • Natural Vegetation: Herbaceous plants like grasses, mosses (e.g., reindeer moss), lichens, and liverworts dominate.
  • Animal Life:
    • Large mammals: Polar bears, caribou, musk oxen, and Arctic foxes.
    • Smaller animals: Lemmings and Arctic hares, which change fur color with the seasons.
    • Migratory birds, like snow geese and loons, use the tundra for breeding during summer.

Reasons for Arctic Emitting Greenhouse Gases

• Thawing Permafrost:
  • Rising global temperatures are causing permafrost to thaw.
  • When the frozen soil thaws, microbes become active, breaking down the trapped organic matter, releasing carbon dioxide (CO₂) and methane (CH₄).
  • Methane is especially concerning because it is a more potent greenhouse gas than CO₂.
• Wildfires:
  • As temperatures rise, wildfires in Arctic regions are becoming more frequent.
  • Fires release large amounts of carbon stored in the vegetation and soil, further accelerating global warming.
• Arctic Warming Trends:
  • The Arctic is heating up four times faster than the global average, causing rapid changes in the biome.
  • Melting ice and warming soils are significant contributors to greenhouse gas emissions.