Why Arctic tundra is emitting more carbon than it absorbs, for first time in many millennia

Sub : Env

Sec : Climate Change

Context:

The Arctic tundra, once a massive carbon storage system, is now emitting greenhouse gases (GHGs) like carbon dioxide (CO2) and methane (CH4), according to the National Oceanic and Atmospheric Administration’s (NOAA) Arctic Report Card. This shift has significant implications for global warming, as it exacerbates climate change.

How the Arctic Tundra Stores Carbon?

In most ecosystems, carbon cycles through photosynthesis, decomposition, and release back into the atmosphere.
In the Arctic, cold temperatures slow decomposition, trapping organic matter like plant and animal remains in permafrost (ground frozen for at least two years).
Arctic soils hold over 1.6 trillion metric tonnes of carbon — double the amount of carbon in Earth’s atmosphere.

Why Is the Arctic Tundra Emitting More Carbon?

The Arctic is warming four times faster than the global average.
In 2024, the region recorded its second-warmest annual temperature since 1900.
Thawing permafrost activates microbes that break down organic matter, releasing CO2 and CH4 into the atmosphere.
- Permafrost is like frozen chicken—safe until thawed, after which microbes cause decay.
Increase in Wildfires:
- Wildfire intensity and frequency in the Arctic are at record highs.
- Wildfires contribute to GHG emissions and accelerate permafrost thaw.
- Between 2001 and 2020, wildfires and rising temperatures caused the tundra to release more carbon than it absorbed — likely for the first time in millennia.

Consequences and Next Steps:

The Arctic emitting more GHGs worsens climate change, leading to more extreme weather and global temperature rise.
Reducing global GHG emissions can help the tundra regain its role as a carbon sink.
The Global Carbon Project estimates 2024 emissions (including fossil fuels and land-use changes) to reach 41.6 billion tonnes, up from 40.6 billion tonnes in 2023.

Source: IE