Thawing permafrost will reveal industrial legacies

There are an estimated 10,000 to 20,000 contaminated industrial sites located in Arctic permafrost regions. These range from micro-dumps full of toxic sludge from oil and gas exploration to abandoned military installations to stockpiles of mining debris. In many cases, operators assumed that the permafrost would reliably and permanently seal off these toxic substances, so they did not make adequate disposal efforts. But as MORITZ LANGER explains, it is not yet clear what will happen to these remnants of the Arctic’s industrial past when the permafrost thaws.

In the popular imagination, the Arctic is a harsh wilderness of endless tundra crisscrossed by rivers of crystal-clear water and home to wildlife roaming untouched by humans. However, this picturesque image masks a stark reality in Arctic regions that have been exploited for industrial purposes.

In truth, the Arctic is a treasure trove of natural resources, including fossil fuels and rare materials considered essential to our modern society. Industrial exploitation of the area dates back to the late 19th century, with the gold rush in Canada and Alaska, and now takes the form of extensive oil and gas exploration and intensive mining of rare materials.

Decades of intensifying industrial activities have led to an accumulation of environmentally hazardous substances in Arctic permafrost regions. What we don’t know is what will happen to these industrial legacies when the permafrost begins a large-scale thaw.

– Moritz Langer, researcher, Vrije Universiteit Amsterdam and the Alfred-Wegener-Institute for Polar and Marine Research

Decades of intensifying industrial activities have led to an accumulation of environmentally hazardous substances in Arctic permafrost regions. What we don’t know is what will happen to these industrial legacies when the permafrost begins a large-scale thaw. And it is coming: our climate observations clearly show that the Arctic is warming two to four times faster than the rest of the globe.

Thawing compromises stability

This strong warming has severe and visible impacts on the continuously frozen ground known as permafrost. Even in extremely northern and frigid places like Ellef Ringnes Island in Canada (at 78°N), we can see signs that the permafrost is starting to thaw. Unfortunately, the stability of Arctic infrastructure depends heavily on this frozen foundation, whether it is supported by structures anchored into the permafrost or erected on top using insulating gravel pads.

Either way, as the Earth’s surface warms, the summer thaw will penetrate more deeply, thinning this frozen foundation. Permafrost doesn’t have to thaw completely to compromise the stability of infrastructure—even a slight warming of the ground can reduce its strength significantly. This is why warming in the Arctic poses a risk to various structures, including those used to transport, store or dispose of hazardous substances.

The vulnerability of industrial sites that are located on thawing permafrost was starkly demonstrated in the Russian city of Norilsk in 2020, when the collapse of a fuel tank led to a devastating spill of 17,000 tons of diesel into the surrounding environment. This incident vividly showcases the dangers posed by industrial activities and infrastructure located on thawing permafrost.

Addressing knowledge gaps

Moreover, this disaster shed light on a critical issue: we still don’t have enough knowledge or data on industrial infrastructure and activities in permafrost regions to understand exactly how things will unfold. The available information is markedly inadequate for conducting a comprehensive risk assessment on a larger scale. Such an assessment would require detailed and reliable data about the type, quantity, status and whereabouts of hazardous substances used or disposed of in the Arctic as part of industrial operations.

To shed some light on the issue, our team of permafrost and climate researchers analyzed the available data on industrial and contaminated sites in the North American Arctic. In doing so, we noticed a clear link between the presence of industrial sites and contamination. It might seem unsurprising that more contamination is found where there is more industry, but a key strength of this study was that it enabled us to predict the number of contaminated sites in areas where data were lacking.

Predicting contamination in areas with data gaps still involves significant uncertainties—especially when trying to apply the findings from one region to another—due to distinct environmental, political and legislative contexts. However, by including reported contamination incidents from Russia in our analysis, we were able to substantially reduce the uncertainty and establish a more acceptable range for the estimate. In total, we identified more than 4,500 industrial sites across the entire Arctic permafrost region that are likely associated with 10,000 to 20,000 contaminated sites.

The tip of the iceberg

By applying this database to models that predict the thawing of permafrost under different climate scenarios, we learned that many of the Arctic’s industrial and contaminated sites are located on permafrost that is still relatively stable today, but will probably experience thawing before the end of this century. Because the database we used is not complete, we must assume that our analysis only scratches the surface, and that there are probably a great many more industrial and contaminated sites.

Our findings underscore the urgent need to better understand the risks associated with the legacy of industrial activities in permafrost regions. Industries, authorities and local communities must proactively prepare for the impending changes related to thawing permafrost in the Arctic so they can prevent potential environmental disasters from contaminants on the move.

At this critical moment, increased awareness, collaboration and strategic planning are essential to protect the Arctic’s fragile ecosystems and inhabitants.