Reviews & Syntheses : Arctic Fire Regimes and Emissions in the 21 st 1 Century 2

In recent years, the Pan-Arctic region has experienced increasingly extreme fire seasons. Fires in the northern high 22 latitudes are driven by current and future climate change, lightning, fuel conditions, and human activity. In this context, 23 conceptualizing and parameterizing current and future Arctic fire regimes will be important for fire and land management as 24 well as understanding current and predicting future fire emissions. The objectives of this review were driven by policy 25 questions identified by the Arctic Monitoring and Assessment Programme (AMAP) Working Group and posed to its Expert 26 Group on Short-Lived Climate Forcers. This review synthesises current understanding of the changing Arctic and boreal fire 27 regimes, particularly as fire activity and its response to future climate change in the Pan-Arctic has consequences for Arctic 28 Council states aiming to mitigate and adapt to climate change in the north. The conclusions from our synthesis are the 29 following: (1) Current and future Arctic fires, and the adjacent boreal region, are driven by natural (i.e., lightning) and human30 caused ignition sources, including fires caused by timber and energy extraction, prescribed burning for landscape management, 31 and tourism activities. Little is published in the scientific literature about cultural burning by Indigenous populations across 32 the Pan-Arctic and questions remain on the source of ignitions above 70°N in Arctic Russia. (2) Climate change is expected 33 to make Arctic fires more likely by increasing the likelihood of extreme fire weather, increased lightning activity, and drier 34 https://doi.org/10.5194/bg-2021-83 Preprint. Discussion started: 8 April 2021 c © Author(s) 2021. CC BY 4.0 License.