![]() Linkages and feedbacks exist between these three variables which can either enhance or suppress fire activity (Bowman et al., 2020 Marlon, 2020). Fire regimes are a function of climate, human activity, and land use. A long-term increase in both extreme fire weather and fire season length has been observed in parts of Australia (BOM and CSIRO, 2020), and there has been a global increase in the frequency of compound fire weather and meteorological drought events (Richardson et al., 2022). In northern California and Oregon, the likelihood of extreme autumn fire weather has increased by 40% (Hawkins et al., 2022), and both the frequency and size of wildfires have increased in the western United States (Abatzoglou & Williams, 2016 Iglesias et al., 2022). In many areas, instances of dangerous fire weather are increasing (Jones et al., 2022). Wildfires are a significant hazard with ∼40% of the Earth's terrestrial surface being fire prone, and ∼3% of the terrestrial surface burning each year (Chapin et al., 2011 Giglio et al., 2010). Longer records of fire activity will help to improve models for forecasting how fire regimes might change with climate change and how ecosystems might respond to those changes. ![]() The case studies are an investigation of ash geochemistry, an analysis of post-fire changes in sulfate, a study of how intense fires are linked to climate, and an exploration of whether deep cave stalagmites may also record past fires. We detail the development of this emerging field, starting with cave dripwater monitoring results, we then give an overview of relevant laboratory and statistical methods, and provide four case studies. Here we review recent advances of this new application in paleofire research. As they grow, stalagmite chemistry changes according to the climate and environment, and recent research has shown that elements from wildfire ash can become incorporated into the speleothem archive. Natural cave decorations (speleothems) have recently been found to include information about fire events. ![]() We can use paleoenvironmental data to learn more. Most of our knowledge about wildfires comes from satellite data, which are not long enough to fully understand past fire behavior. Wildfires are a global hazard, and are likely to become larger, more common, and more intense with climate change. We conclude the paper by outlining future research directions for paleofire applications. Finally, we present four case studies from southwest Australia which: (a) explore the geochemistry of ash leachates, (b) detail how sulfate isotopes may be a proxy for post fire ecological recovery, (c) demonstrate how a catastrophic paleofire was linked to changes in climate and land management, and (d) investigate whether deep caves can record past fire events. We then describe the ideal speleothem sample for paleofire research and offer a summary of applicable laboratory and statistical methods. We give a concise overview of fire regimes and common paleofire proxies, describe past attempts to use stalagmites to investigate paleofire, and describe the physical basis through which speleothems can record past fires. Here we present a review of this emerging application in speleothem paleoenvironmental science. Recently, speleothems have been shown to record past fire events (Argiriadis et al., 2019, McDonough et al., 2022, Homann et al., 2022, ). Speleothems, naturally occurring cave formations, are widely used in paleoenvironmental research as they are absolutely dateable, occur on every ice-free continent, and include multiple proxies. Environmental proxy archives can extend our knowledge of past fire activity. Improved understanding of past fires is necessary to better forecast how fire regimes might change with future climate change, to understand ecosystem resilience to fire, and to improve data-model comparisons. Wildfires affect 40% of the earth's terrestrial biome, but much of our knowledge of wildfire activity is limited to the satellite era.
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