Rao, KrishnaWilliams, A. ParkDiffenbaugh, NoahYebra, MartaKonings, Alexandra G2023-07-182023-07-182397-334Xhttp://hdl.handle.net/1885/294333Extreme wildfires extensively impact human health and the environment. Increasing vapour pressure deficit (VPD) has led to a chronic increase in wildfire area in the western United States, yet some regions have been more affected than others. Here we show that for the same increase in VPD, burned area increases more in regions where vegetation moisture shows greater sensitivity to water limitation (plant-water sensitivity; R2 = 0.71). This has led to rapid increases in human exposure to wildfire risk, both because the population living in areas with high plant-water sensitivity grew 50% faster during 1990–2010 than in other wildland–urban interfaces and because VPD has risen most rapidly in these vulnerable areas. As plant-water sensitivity is strongly linked to wildfire vulnerability, accounting for ecophysiological controls should improve wildfire forecasts. If recent trends in VPD and demographic shifts continue, human wildfire risk will probably continue to increase.K.R. was funded by the NASA Earth and Space Science Fellowship, and the Stanford Data Science Scholarship. A.G.K. and K.R. were also funded by NASA Terrestrial Ecology award 80NSSC18K0715 through the New Investigator Program, the UPS Endowment Fund at Stanford, the Stanford Sustainability Initiative and the Stanford Woods Institute for the Environment. A.P.W. was funded by the Zegar Family Foundation. N.S.D. was funded by Stanford University. M.Y. was funded by the Australian National University.application/pdfen-AU© 2022 The authorshttp://creativecommons.org/licenses/by/4.0/202210.1038/s41559-021-01654-22022-05-15Creative Commons Attribution licence