In the Arctic tundra and boreal forest, where wildfire has naturally been infrequent, burned area showed statistically significant increases of ~50% yr1 across Siberia, Russia, from 1996 to 2015  and 2% yr-1 across Canada from 1959 to 2015 . Wildfire burned ~6% of the area of four extensive Arctic permafrost regions in Alaska, USA, eastern Canada and Siberia from 1999 to 2014 . In boreal forest in the Northwest Territories, Canada and Alaska, USA, the area burned by wildfire increased at a statistically significant rate of 6.8% yr1 in the period 1975-2015, , with smouldering below-ground fires that lasted through the winter covering ~1% of burned area in the period 2002-2016 . While burned area was correlated with temperature and reduced precipitation in Siberia  and correlated with lightning, temperature and precipitation in the Northwest Territories and Alaska , no attribution analyses have examined relative influences of climate and non-climate factors.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report