This hidden reserve is becoming increasingly important as the Arctic warms. When permafrost thaws, ancient plant and animal material that has remained frozen for thousands of years can begin to decompose. This process releases greenhouse gases including carbon dioxide and methane, which may increase global warming.
A landmark 2015 study by researchers from the University of Cambridge and the University of Colorado estimated that these additional emissions could lead to additional global economic damage of up to $43 trillion by 2200 under the study’s A1B emissions scenario.
The number is not a prediction of a future bill or a direct assessment of Alaska lands. Instead, it represents researchers’ estimate of additional economic losses associated with greenhouse gases released as Arctic permafrost melts.
Why Alaskan permafrost is important for the entire planet
Permafrost is ground that has remained frozen for long periods, often containing vast amounts of organic matter accumulated over thousands of years.
Researchers estimate that Arctic permafrost contains approximately 1,700 gigatonnes of carbon. While this carbon remains frozen, the decomposition process slows down considerably. Rising temperatures could change this equation.
As permafrost thaws, microorganisms can break down previously preserved materials. Some carbon can then enter the atmosphere in the form of carbon dioxide, while methane can also be produced under oxygen-poor conditions. This creates a worrying cycle: warming causes ice to melt, melting ice releases greenhouse gases, and these emissions can contribute to further global warming.
How did scientists arrive at the $43 trillion figure?
This estimate came from an economic modeling process and not from setting a price for the permafrost itself.
Cambridge researcher Chris Hope and University of Colorado researcher Kevin Schaefer examined the economic consequences of carbon dioxide and methane released from thawing permafrost. Their research used the PAGE09 integrated assessment model to link incremental greenhouse gas emissions to expected climate-related damages.
Under the A1B scenario examined in the study, the estimated net present value of climate change impacts increased from $326 trillion to $369 trillion by 2200 once permafrost emissions were included.
This represents an increase of about 13%, or about $43 trillion.
The researchers estimated that nearly $33 trillion of additional damage was associated with carbon dioxide and about $8 trillion with methane, with the remainder attributable to interactions between the gases.
This number comes with a large amount of uncertainty
The $43 trillion figure may seem final, but the researchers themselves have highlighted significant uncertainty in the modeling.
The estimated range of the additional economic impact extends from about $3 trillion to $166 trillion at the 5th to 95th percentile.
This wide range reflects the difficulty of predicting how quickly permafrost will thaw, how much carbon will be released, how greenhouse gases will affect future temperatures, and how climate change will translate into economic losses over nearly two centuries.
In other words, the study’s headline figure is best understood as a typical estimate within a given emissions pathway, rather than a guaranteed outcome.
Why is the economic damage spreading beyond Alaska?
Permafrost thaw may occur thousands of kilometers from major population centers, but its potential consequences are global.
Once carbon enters the atmosphere, the resulting greenhouse gases no longer remain trapped in the Arctic. Additional warming could affect agriculture, human health, ecosystems and energy demand in regions around the world.
The Cambridge researchers have also linked rising temperatures to risks including flooding, severe weather and the loss of additional ice cover.
This makes the frozen ground in the Arctic an unusual climate threat: carbon is stored locally, but the consequences of releasing it could be worldwide.
Reducing emissions can reduce harm
The 2015 research also pointed to a potential way to limit the economic consequences.
The researchers estimated that an aggressive strategy to reduce greenhouse gas emissions could reduce the additional economic impact associated with thawing permafrost by as much as $37 trillion compared to the scenario they analyzed.
The implication was clear: limiting overall global warming could also reduce the amount of carbon released by thawing permafrost.
What the latest research says about thawing permafrost
The original estimate of $43 trillion dates back to 2015, so it should not be presented as a current projection of the ultimate cost of global warming in the Arctic.
But subsequent research added another concern: sudden thawing of permafrost.
Scientists have found that sudden melting can expose carbon more quickly than the gradual processes captured by some climate models. In certain environments, these changes can also create favorable conditions for methane emissions.
This means that the future behavior of permafrost may depend not only on how much the Arctic warms, but also on how quickly the frozen and uneven landscape changes.
Alaska’s tundra is more than just frozen soil
The vast Arctic landscape can seem far removed from the global climate debate. However, underneath there is a reserve of carbon capable of impacting the atmosphere far beyond Alaska.
So the startling lesson from the Cambridge and Colorado research is not simply the $43 trillion cost. It is the magnitude of the relationship between the seemingly unattainable landscape and the global economy.
Permafrost may be frozen ground, but the carbon in it is part of an active climate system. As temperatures rise in the Arctic, keeping carbon locked underground may become increasingly important for reducing the economic and environmental costs of climate change.
