Observed Impacts of Anthropogenic Climate Change on Wildfire in California

Abstract Recent fire seasons have fueled intense speculation regarding the effect of anthropogenic climate change on wildfire in western North America and especially in California. During 1972–2018, California experienced a fivefold increase in annual burned area, mainly due to more than an eightfold increase in summer forest‐fire extent. Increased summer forest‐fire area very likely occurred due to increased atmospheric aridity caused by warming. Since the early 1970s, warm‐season days warmed by approximately 1.4 °C as part of a centennial warming trend, significantly increasing the atmospheric vapor pressure deficit (VPD). These trends are consistent with anthropogenic trends simulated by climate models. The…

• ZF
  Zegar Family Foundation
• UO
  University of Tasmania
• NO
  National Oceanic and Atmospheric Administration
• UG
  U.S. Geological Survey

  Award: G18AC00320
• LE
  Lamont-Doherty Earth Observatory, Columbia University
• OO
  Office of the President, University of California

  Award: MRP-17-446315
• SC
  Southwest Climate Adaptation Science Center

  Award: G18AC00320