Northern Alarms: Why the Arctic Matters for the Planet’s Climate

Due to climate change, large parts of the tundras in the far north of the Earth have begun to emit more greenhouse gases than they sequester.

The Arctic region located near the North Pole plays a central role in carbon sequestration in vegetation and soil.
Global warming and related climate changes strongly affect this region and may create a self reinforcing process.
Wildfires increases the greenhouse gas carbon dioxide released into the atmosphere.

However, there are other areas in the world that are important for the carbon cycle.
One of them is the Arctic region stretching north of latitude 65° up to the North Pole, partly covered with vegetation that absorbs carbon dioxide, releases oxygen and stores carbon in plant tissues.
The Arctic region is therefore extremely important nearly half of the Earth’s soil carbon is estimated to be in the Arctic.

The Arctic is strongly affected by global climate change and is warming very rapidly.
As a result, its carbon balance has changed dramatically over recent decades. Large areas now release more carbon dioxide than they capture.

Changes in carbon sequestration or release depend on soil type, vegetation, and other factors.
Study published this year in Nature Climate Change found that during the first two decades of the current millennium, the Arctic overall contributed to carbon sequestration from the atmosphere.
However, in large areas, the picture was very different.
More than a third of the Arctic land actually released large amounts of carbon dioxide.

Researchers examined two ecological systems that make up the Arctic. Precipitation there is very low less than most deserts in the world and temperatures remain below zero for 6–10 months a year. Only low vegetation such as mosses survives, growing for short periods before the ground freezes again.

Study found that while more carbon dioxide than it emits overall, in some of particularly tundra regions, the opposite occurs.
After years of carbon sequestration the tundra now releases large amounts of greenhouse gases.
Scientists attribute this to permafrost thaw caused by climate warming, which releases gases trapped between soil and frozen ice, along with vegetation changes and soil drying.
Sparse tundra vegetation cannot compensate for the released carbon dioxide.

These phenomena are caused by Arctic warming, where average temperatures have risen by about three degrees since 1971.
Tundra vegetation adapted to specific temperatures and warming harms new growth, reducing carbon stored in plants.
Similar changes are observed in the taiga, though currently more carbon is still stored there than released.

Researchers note that taiga vegetation is increasing, slightly boosting carbon sequestration.
However, this also increases wildfires which release large amounts of carbon dioxide.
Combined trends indicate that the Arctic is moving from being a major carbon sink to nearly neutral or even a source of carbon emissions.

In recent years, northern forest wildfires have become almost routine, intensified by global climate change.
Fires release carbon and recovering takes time.
If fires continue, the Arctic may shift from a massive carbon storage mechanism to a significant source of emissions, on top of the vast amounts of greenhouse gases humans continue to release.

The study highlights an important trend and enriches understanding of current changes in the Arctic and how these changes are expected to affect local and global ecology in the coming years, alongside the ongoing rise in global average temperatures.