2 In summary, anthropogenic climate change caused drought-induced tree mortality of up to 20% in the period 1945-2007 in western North America, the African Sahel and North Africa, via global temperature increases of 0.3ºC-0.9ºC above the pre-industrial period and increases in aridity, and it contributed to over 100 other cases of drought-induced tree mortality in Africa, Asia, Australia, Europe and North and South America . Field observations document accelerating mortality rates, rising background mortality and post-mortality vegetation shifts . Water stress, leading to plant hydraulic failure, is the principal mechanism of drought-induced tree mortality. Timber cutting, agricultural expansion, air pollution and other non-climate factors also contribute to tree death.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report