Reviews and syntheses: Arctic fire regimes and emissions in the 21st century

Abstract

Abstract. In recent years, the pan-Arctic region has experienced increasingly extreme fire seasons. Fires in the northern high latitudes are driven by current and future climate change, lightning, fuel conditions, and human activity. In this context, conceptualizing and parameterizing current and future Arctic fire regimes will be important for fire and land management as well as understanding current and predicting future fire emissions. The objectives of this review were driven by policy questions identified by the Arctic Monitoring and Assessment Programme (AMAP) Working Group and posed to its Expert Group on Short-Lived Climate Forcers. This review synthesizes current understanding of the changing Arctic and boreal fire regimes, particularly as fire activity and its response to future climate change in the pan-Arctic have consequences for Arctic Council states aiming to mitigate and adapt to climate change in the north. The conclusions from our synthesis are the following. (1) Current and future Arctic fires, and the adjacent boreal region, are driven by natural (i.e. lightning) and human-caused ignition sources, including fires caused by timber and energy extraction, prescribed burning for landscape management, and tourism activities. Little is published in the scientific literature about cultural burning by Indigenous populations across the pan-Arctic, and questions remain on the source of ignitions above 70∘ N in Arctic Russia. (2) Climate change is expected to make Arctic fires more likely by increasing the likelihood of extreme fire weather, increased lightning activity, and drier vegetative and ground fuel conditions. (3) To some extent, shifting agricultural land use and forest transitions from forest–steppe to steppe, tundra to taiga, and coniferous to deciduous in a warmer climate may increase and decrease open biomass burning, depending on land use in addition to climate-driven biome shifts. However, at the country and landscape scales, these relationships are not well established. (4) Current black carbon and PM2.5 emissions from wildfires above 50 and 65∘ N are larger than emissions from the anthropogenic sectors of residential combustion, transportation, and flaring. Wildfire emissions have increased from 2010 to 2020, particularly above 60∘ N, with 56 % of black carbon emissions above 65∘ N in 2020 attributed to open biomass burning – indicating how extreme the 2020 wildfire season was and how severe future Arctic wildfire seasons can potentially be. (5) What works in the boreal zones to prevent and fight wildfires may not work in the Arctic. Fire management will need to adapt to a changing climate, economic development, the Indigenous and local communities, and fragile northern ecosystems, including permafrost and peatlands. (6) Factors contributing to the uncertainty of predicting and quantifying future Arctic fire regimes include underestimation of Arctic fires by satellite systems, lack of agreement between Earth observations and official statistics, and still needed refinements of location, conditions, and previous fire return intervals on peat and permafrost landscapes. This review highlights that much research is needed in order to understand the local and regional impacts of the changing Arctic fire regime on emissions and the global climate, ecosystems, and pan-Arctic communities.

Rare and Extreme Wildland Fire in Sakha in 2021

“…Under a warmer climate in the future, more severe fire weather, more area burned, more ignitions and a longer fire season are expected [3]. In recent years, the pan-Arctic region has experienced increasingly extreme fire seasons [4].…”

A review of the importance of mineral nitrogen cycling in the plant-soil-microbe system of permafrost-affected soils—changing the paradigm

“…Also in dry tundra heath a recent study showed fire-induced mineral N increases (Xu et al 2021). However, implications of arctic fires for N biogeochemistry remain severely understudied (McCarty et al 2021).…”

Classification of Fire Damage to Boreal Forests of Siberia in 2021 Based on the dNBR Index

“…Wildfires in Siberia make up a significant part of the statistics of annual damage to vegetation in the world [1][2][3]. As materials of recent years show, areas of fires tend to rise in many regions of the world.…”

“…Climate change will affect the occurrence of forest fires in northern regions. Today, this issue is discussed considerably for boreal forest zone [3,6]. In this direction, future fire impact on boreal forests of Siberia is a very important issue as well.…”

“…We quantified the following issues for conditions of eastern Siberia: (a) the proportion of the different degrees of fire impact on the various vegetation types, (b) areas of the class of "healthy/unburned vegetation" within remotely detected fire scars, and (c) "standreplacement fires" areas for different vegetation types, close tree stands, sparse stands, and tundra of eastern Siberia. Further study of this issue is necessary for predictive modeling of the fire impact on forests under climate change [33] and forest fire regimes increasing at the subregional level [2][3][4]6].…”