The IPCC AR6 WGI assessed fire weather , while this chapter assesses the impacts of changes in fire weather: burned area and fire frequency. The global increases in temperature from anthropogenic climate change have increased aridity and drought, lengthening the fire weather season  on one-quarter of global vegetated area and increasing the average fire season length by one-fifth from 1979 to 2013 . Climate change has contributed to increases in the fire weather season or the probability of fire weather conditions in the Amazon , Australia , Canada , central Asia , East Africa  and North America . In forest areas, the burned area correlates with fuel aridity, a function of temperature; in non-forest areas, the burned area correlates with high precipitation in the previous year, which can produce high grass fuel loads . Fire use in agriculture and raising livestock or other factors have generated a second fire season on approximately one-quarter of global land where fire is present, despite sub-optimal fire weather in the second fire season . In summary, anthropogenic climate change, through a 0.9ºC surface temperature increase since the pre-industrial period, has lengthened or increased the frequency of periods with heat and aridity that favour wildfire on up to one-quarter of vegetated area since 1979 .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report