The Polar Retrospective looks at stories of the past week that are related to the Arctic and Antarctic and focuses on one or more aspects. This time the focus is on the Arctic, from where the numerous fires also send toxic pollutants to the southern regions, as Elvis once sang, “Return to sender”.
Fires of an unprecedented magnitude are still raging in large parts of the Arctic. The size of the affected areas in the Arctic regions has reached new record levels this year. According to data from the EU’s Copernicus Atmosphere Monitoring Service (CAMS), at least. In addition to Russia, which has reported the most fires north of the Arctic Circle, Canada and Alaska have also had to contend with a large number of fires of various sizes this year. The extremely dry months of June and, in some regions, July were mainly responsible for these fires. The permafrost soil, which normally becomes very moist due to the thawing, was quickly dried out by the high air temperatures, thus creating the perfect breeding ground for fires. Thousands of square kilometers of arctic tundra were lost in a very short time, with both expected and unexpected consequences.
More than an increase in greenhouse gas emissions
One of the long-known consequences of such Arctic fires is the massive increase in carbon emissions. The authorities in Canada, for example, state that although the amount of emissions this year did not reach the record levels of 2023, they are still among the highest ever measured. And in other regions too, the amount of carbon released into the air was noted to be much higher than the long-term average.
However, the smoke not only transports carbon into the atmosphere, but also numerous other substances that had previously been quietly bound in the permafrost soil of the Arctic. A Canadian study published in the journal Environmental Research Letters at the end of July warns of a massive release of arsenic, a very potent toxicant. According to the three authors of the study, fires around the city of Yellowknife in the Northwest Territories alone have released between 69 and 183 tons of arsenic into the air this year. These quantities of this dangerous pollutant could then be transported by winds and atmospheric currents to other, more densely populated areas further south.
In their work, the team warns that such events depend on the type and location of the fire. Places that are related to mining activities in the area and where factors such as fire temperature, soil type and depth of the fire are favorable are more at risk than elsewhere in the Arctic and sub-Arctic.
Additionally, with rising temperatures in the Arctic and more frequent fires, such emissions of pollutants are also likely to be recorded more frequently. If adding to this the changes in the atmosphere, which are transporting air masses southwards more frequently, the concentrations of pollutants in these southern areas are likely to increase. According to expert teams, this in turn creates a significantly higher risk of lung diseases and other health issues.
Reurn to sender
The pollutants that are transported from the Arctic to other regions are partly of natural origin and include not only arsenic, which is deposited in the very peaty permafrost soil, but also, for example, mercury. However, the origins of these substances are not only due to weathering or volcanism. Human sources such as mining and various industrial production chains have also been identified. These substances originate from regions far to the south and are transported to the Arctic by atmospheric processes and ocean currents, where they accumulate in the permafrost soils. As an example, a study from 2021 was able to prove beyond doubt that pollutants from the Indus-Ganges region of India and Bangladesh are transported to almost all parts of the Arctic within a few days and deposited there. Another study concluded that around 22 percent of all pollutants in the Arctic originate from the southern regions of the Arctic nations and are transported northward by air masses.
Given that mining companies are securing new areas for the extraction of raw materials such as gold, iron and rare earths in Arctic regions, environmental protection organizations in particular are concerned that the increasing number of fires could potentially exacerbate the problem of pollution.
The irony of the whole story: the effects of climate change, such as these wildfires, release such pollutants and send them back in the opposite direction to more southerly regions… returned to sender with best regards from the Arctic.
Dr. Michael Wenger, Polar Journal AG
Link to the study: Sutton et al (2024) Environ Res Let 19(6) Globally-significant arsenic release by wildfires in a mining-impacted boreal landscape, DOI: 10.1088/1748-9326/ad461a
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