In an article authored by John T. Abatzoglou and A. Park Williams in Proceedings of the National Academy of Sciences of the United States of America titled ” Impact of anthropogenic climate change on wildfire across western US forest ” the authors in the Abstract explain what the science shows with respect to human influences on wildfire in Western U.S. Forest. An excerpt from that section.
Anthropogenic climate change accounted for ∼55% of observed increases in fuel aridity from 1979 to 2015 across western US forests, highlighting both anthropogenic climate change and natural climate variability as important contributors to increased wildfire potential in recent decades. We estimate that human-caused climate change contributed to an additional 4.2 million ha of forest fire area during 1984–2015, nearly doubling the forest fire area expected in its absence.