Historically, the Arctic tundra has been a natural carbon sink for thousands of years, capturing and storing carbon in its permafrost—a layer of soil that remains frozen year-round. The frozen soil traps organic material, preventing it from decomposing and releasing carbon into the atmosphere. Estimates suggest that the Arctic permafrost stores approximately 1,700 billion tons of carbon, nearly twice the total carbon currently in Earth’s atmosphere. As per recent research and studies, the Arctic tundra is now emitting more carbon than it absorbs.

A Net Carbon Emitter for the First Time in Millennia

The 2024 Arctic Report Card, published by the US National Oceanic and Atmospheric Administration (NOAA), highlights this transformation as one of the most alarming climate milestones of the decade—the Arctic tundra is now emitting more carbon than it absorbs.

Significant factors that led to this shift are the Increasing number of frequent and intense wildfires, which release vast amounts of stored carbon directly into the atmosphere. The permafrost thaws due to the rising arctic temperatures of the frozen soil, triggering the decomposition of organic matter. Accelerated microbial activity from thawing the soil activates microbes that decompose organic material, releasing carbon dioxide (CO₂) and Methane (CH₄)—potent greenhouse gases.

The global impact of the transition of the Arctic tundra is now emitting more carbon than it absorbs, converting from a carbon sink to a carbon source, an echoing chain. This biome is responsible for maintaining consistent weather patterns on which we have come to rely.

The worsening of global warming through the release of trapped greenhouse gases accelerates the greenhouse effect, leading to faster global temperature increases. Methane expulsion also plays a significant role. Methane, which is 25 times more effective than CO₂ at trapping heat over 100 years, contributes to short-term spikes in atmospheric warming.

Emissions from permafrost thaw and wildfires have increased the climatic feedback loop, leading to higher global temperatures.

This, in turn, causes further permafrost thaw and wildfire activity, creating a self-reinforcing cycle. The sea level has risen, and the weather has begun to span the extremes with how the Arctic tundra emits more carbon than it absorbs. Global warming is inevitable. It contributes to melting ice sheets, raising sea levels, and increasing the frequency of extreme weather events such as hurricanes, droughts, and floods.

Also Read: Arctic Tundra Shifts From Carbon Sink To Source Amid 11 Years Of Continuous Warming

Alarming Rise in Arctic Temperatures

Over the past decade, Arctic surface air temperatures have shown a consistent upward trend, underscoring the region’s long-term effects of climate change. Actors contributing to these rising temperatures include reduced sea ice with the loss of reflective ice cover, which leads to more solar radiation being absorbed by dark ocean waters, amplifying regional warming (known as the albedo effect), and increased atmospheric heat transport as warmer air masses from lower latitudes are reaching the Arctic more frequently.

The warming climate has paradoxical effects on the Arctic ecosystem, with both short-term benefits and long-term consequences.

In the short term, rising temperatures promote plant growth, extend the growing season, and boost plant productivity. This boost in growth occurs when plants, which in turn results in more absorption of carbon dioxide (CO₂) during photosynthesis, temporarily offsetting emissions and creating the illusion of a stabilizing environment.

In the long run, this temperature rise can trigger permafrost to thaw the frozen soil layers rich in organic material—to melt. This thawing permafrost releases significant quantities of greenhouse gases, including Carbon Dioxide (CO₂), which is a long-lasting greenhouse gas contributing to gradual warming, and Methane (CH₄), not as long existing as carbon dioxide with its short-lived nature but 25 times more potent greenhouse gas than CO₂ over 100 years.

This process has already released millions of tons of carbon annually, shifting the Arctic from a carbon sink to a carbon source.

Arctic warming has broader implications. The dual effects create a dangerous climate feedback loop, where warming triggers further emissions, leading to accelerated global warming. The changing Arctic temperatures also have cascading impacts on international systems.

Also Read: 7 Rare Plants From The Tundra Biome

Permafrost Thaw: A Carbon Time Bomb

Mechanism of emissions thawing the permafrost as it acts as a natural carbon storage system, locking in organic material that never decomposed due to the freezing temperatures. As global temperatures rise, permafrost thaws, exposing these ancient organic materials to microbial activity. Decomposition and greenhouse gas release microbes break down the organic matter, producing greenhouse gases like carbon dioxide (CO₂) and methane (CH₄).

Methane Production as methane is the primary gas released in oxygen-poor, waterlogged environments such as Arctic lakes and wetlands. It is more effective at trapping heat than CO₂, making its contribution to global warming disproportionately large.

Carbon dioxide is produced in drier, oxygen-rich conditions, and CO₂ is predominantly released during decomposition. This accelerates the feedback loop, where global warming further thaws permafrost, exposing even more organic material and increasing emissions, creating a dangerous climate feedback loop.

A 2022 assessment indicated that permafrost carbon emissions could add between 14 and 175 billion tonnes of CO₂ equivalent per 1°C of warming by 2100. This figure represents a significant portion of global carbon emissions comparable to the combined annual emissions of major industrial nations like the United States and China.

Methane leaks from Arctic lakes and wetlands are becoming significant methane sources. Thawed organic material in anaerobic conditions releases this potent greenhouse gas directly into the atmosphere. Methane emissions from Arctic lakes and wetlands could increase sharply as thawing progresses, contributing to short-term spikes in global temperatures.

Once released, irreversible consequences occur; these gases are virtually impossible to recapture, meaning the carbon emissions from permafrost thaw represent a permanent addition to atmospheric greenhouse gases.

Broader implications of thawing permafrost are not just a regional problem; their emissions have global consequences with sea level rises as accelerated warming could hasten ice melt, contributing to rising sea levels. The ecosystem disruption is yet another side effect as wildlife and plant species dependent on cold climates face threats of extinction. The human impact as the communities in Arctic regions experience destabilized infrastructure as thawing ground undermines roads, buildings, and pipelines.

Also Read: NASA Exposes Thawing Permafrost as Climate Danger