The landscapes at the fringes of the Arctic, often characterized by their chilling cold, are shifting rapidly. In fact, these regions are warming at a staggering rate two to four times faster than the global average. This drastic change has major implications, particularly concerning the permafrost beneath these “boreal” forests and expansive tundras, which is no longer remaining frozen.

Why is this thawing a cause for concern? Permafrost stores vast amounts of carbon—more than double the amount currently circulating in our atmosphere. As this frozen ground begins to thaw, carbon and nitrogen locked within it are starting to escape into the environment, further aggravating climate change.

Our latest research, part of the Global Carbon Project, reveals a comprehensive greenhouse gas budget that assesses this critical northern permafrost region. The findings provide a mix of sobering realities and some unexpected insights for the future of our climate.

Understanding Permafrost and Its Implications

Permafrost is essentially a permanently frozen layer of ground that contains not just soil, but also ice, rock, and remnants of ancient flora and fauna. Incredibly, this frozen reservoir is home to over a trillion tonnes of carbon—significantly more than all tropical forests combined. The current model shows that while surface soil may thaw during warmer months, deeper layers are now warming with climate change, extending the thawing season and liberating the stored carbon.

As temperatures rise, microbes within thawed soils begin to decompose organic matter, releasing carbon dioxide (CO₂) and, in oxygen-poor environments, methane (CH₄)—the latter being a potent greenhouse gas that warms the atmosphere significantly more than CO₂. This process not only results in increased emissions, but also sets off a ripple effect known as a "positive carbon-climate feedback loop," where warming leads to more emissions, further accelerating climate change.

Recent Findings on Greenhouse Gas Emissions

In our assessment, which draws upon data from 35 research institutions, we calculated the greenhouse gas emissions from permafrost over the period of 2000-2020. Surprisingly, we found that while permafrost acts as a yearly carbon sink—absorbing between 29 million to 500 million tonnes of CO₂—lakes, rivers, and wildfires contribute to its status as a source of methane and nitrous oxide, both significant greenhouse gases.

Wetlands emerged as the largest source of methane emissions, exacerbated by increasing water saturation due to melting permafrost. Furthermore, the study showed that the impending threat of wildfires has escalated, with events in Siberia in 2021 and Canada in 2023 likely contributing to vast increases in greenhouse gas emissions, essentially nullifying any carbon sink effects.

What Lies Ahead

The future trajectory of greenhouse gas emissions from the permafrost region remains uncertain. Current trends indicate rising methane emissions, with potential local permafrost collapse and extreme wildfires posing a significant risk that existing climate models have not adequately accounted for. The stakes are high—without significant reduction in human-driven emissions, the cycle of thawing and subsequent emissions will likely intensify, quickening the pace of global warming.

The Bottom Line

In conclusion, our fight against climate change must prioritize actions to curtail greenhouse gas emissions from human activities. The frozen carbon reserves in permafrost regions are at a tipping point; if we fail to act, we may unleash a catastrophic effect that propels global warming and devastates natural ecosystems. We stand at a crossroads that demands immediate attention and action. The question now is: can we change our course in time to protect our planet?