Why Arctic Tundra is emitting more Carbon than it Absorbs

According to the National Oceanic and Atmospheric Administration’s (NOAA) latest Arctic Report Card, The Arctic Tundra has transitioned from a carbon sink to a carbon emitter.

Table of Contents

About Arctic Tundra

It is a vast, treeless biome characterized by its cold, dry and rocky terrain.
Location: It is the northernmost biome, covering areas north of the Arctic Circle up to the polar ice cap. It is located between the taiga (boreal forest) and the Arctic Ocean.
Permafrost: It refers to permanently frozen soil. During summer, only the upper layer thaws, while deeper layers remain frozen.
- The frozen layer restricts plant root growth and prevents tree growth, resulting in a treeless landscape.
Soil composition: The tundra’s soil is rocky and nutrient-poor due to low decomposition rates. Organic material accumulates in the form of peat and humus (organic matter), making it a significant carbon sink.
Animals: It is home to many animals, including herbivores like lemmings, arctic hares, squirrels and carnivores like arctic foxes, wolves and polar bears.

Key Findings of the NOAA Report

Carbon Storage in the Arctic Tundra

Arctic tundra stores carbon in permafrost, a layer of soil that remains frozen for at least 2 consecutive years.
Cold conditions prevent the decomposition of organic matter, trapping carbon for millennia.
Arctic soils contain over 1.6 trillion metric tonnes of carbon, which is double the amount of carbon in the atmosphere.

Reasons for Increased Carbon Emissions

Rising Temperatures: The Arctic is warming 4 times faster than the global average.
- 2024 had the second-warmest surface air temperatures in the Arctic since 1900.
Thawing permafrost: It is the process by which the ice in permafrost melts, leaving behind soil and water. It activates microbes in the soil, breaking down organic matter and releasing CO2 and methane (CH4).
- CH4 is a more potent GHG than CO2. (Intensifying warming)
Increased Wildfires: The Arctic has seen more frequent and intense wildfires in recent years.
- 2024 was the 2nd-biggest year for wildfire emissions, and 2023 had the worst wildfire season on record.
- Wildfires release GHGs and accelerate permafrost thawing.
Net Carbon Loss: Between 2001 and 2020, the Arctic tundra released more carbon than its plants absorbed, likely for the first time in millennia.