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.
- 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.
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.
