‘Zombie’ fires in the Arctic during Spring-Summer 2020

The forest fires in the Arctic are not a novelty, however, the 2020 fire season started two months earlier and more severely than usual. Despite the expected increase in the number of fires, due to the fires at south in the boreal forest and the unusual warm winter, there is still uncertainty about their sources, and regional and global impacts. This study analyses the changes in these fires and the importance of the indigenous communities in their evaluation.

The fires that started earlier in the Arctic are caused by ‘zombie’ fires, resulting from the continuation of fires that happened in the previous growing season, which are not associated to new ignition sources (e.g. lightning and campfires). These can burn in turf rich in carbon during months or years below the surface, even during the winter months. Despite little information about these events, the increase of their frequency will represent an important feedback in the Arctic fire regime and must be considered in the global system models and simulations of global biomass burning.

Evidences from 2019 and 2020 suggest that the extreme temperatures accompanied by drought are increasing the availability of superficial fuels in the Arctic. New types of tundra and turf are becoming more vulnerable to burning, and the ecosystems considered fire resistant are being burnt. While in the Siberian permafrost fires are common, the 2020 fires occurred in higher latitudes in permafrost with high content of ice (rich in carbon), which is uncommon. The burn of these soils might accelerate thaw and carbon emissions, enhancing even more the climatic feedbacks.

Nowadays the burning mass prediction models are not feasible in the Arctic due to the lack of data. This year’s fires enhanced the necessity to distinguish the importance between ‘zombie’ fires and new ignitions in the Arctic fires, and include that information in the satellites and emission datasets. Although these tools allow to improve the detection of these fires, it is essential to have local observations about the type of burning soil and its location.

Thus, there will be necessary interdisciplinary collaborations between the scientific, local and indigenous communities to better understand the changes in the Arctic fire regime. These communities in remote locations are the first to experiment these changes and have information about this type of events, including signs of these fires during the winter, allowing coordinated efforts e.g. management, ecology and climatic impacts.

The intergovernmental forums that invested in the Arctic protection, involving the indigenous communities as permanent participants, are well positioned in the development of a monitoring fire system. This system will require ground-based monitoring networks, remote sensing and global system models, combining the knowledge from different communities.

These fires are a global problem that requires a global solution, in which the knowledge from indigenous communities will be crucial to its success.


Source: McCarty, J.L., Smith, T.E.L. & Turetsky, M.R. Arctic fires re-emerging. Nature Geoscience 13, 658–660 (2020). DOI: 10.1038/s41561-020-00645-5

Author: Carolina Viceto


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