EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Linked fire activity and climate whiplash in California during the early Holocene

Jessica Oster1, Julia Homann2, Cameron de Wet1, Sebastian Breitenbach3, and Thorsten Hoffmann2
Jessica Oster et al.
  • 1Vanderbilt University, Department of Earth and Environmental Sciences, Nashville, United States of America (
  • 2Johannes Gutenberg-University, Department of Chemistry, Mainz, Germany
  • 3Northumbria University, Department of Geography and Environmental Sciences, Newcastle upon Tyne, UK

Recent wildfire activity in semi-arid regions like western North America exceeds the range of historical records. High-resolution paleoclimate archives such as stalagmites could illuminate the link between hydroclimate, vegetation change, and fire activity in pre-anthropogenic climate states beyond the timescale of existing tree-ring records. Here we present an analysis of levoglucosan, a combustion-sensitive anhydrosugar, and lignin oxidation products (LOPs) in a stalagmite from White Moon Cave in the California Coast Range in order to reconstruct fire activity and vegetation composition across the 8.2 kyr event. Elevated levoglucosan concentrations suggest increased fire activity while altered LOP compositions indicate a shift toward more woody vegetation during the event, with the shift in vegetation preceding the increase in fire activity. These changes are concurrent with increased hydroclimate volatility as shown by carbon and calcium isotope proxies. Together, these records suggest that climate whiplash (oscillations between extreme wetness and aridity) and fire activity in California, both projected to increase with anthropogenic climate change, were tightly coupled during the early Holocene.

How to cite: Oster, J., Homann, J., de Wet, C., Breitenbach, S., and Hoffmann, T.: Linked fire activity and climate whiplash in California during the early Holocene, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-2097,, 2023.