Palaeocene climate warming as a catalyst for wildfire intensification

Abstract

Abstract Wildfire regimes are rapidly intensifying under anthropogenic climate change, the effects of which increasingly threaten the health and stability of global ecosystems and the safety of human populations. Understanding wildfire behavior, independent of human intervention, remains critical to efforts in hazard mitigation and the wider understanding of global fire regimes. Wildfire has occurred throughout prehistory, including within periods of analogous climate warming, though associated research lacks resolution in fire and vegetational records. Here, for the first time, Raman spectroscopy of fossil charcoals preserved in the lacustrine Boltysh 42/11 record highlights multi-phase intensification in fire regimes across a Danian (Early Palaeocene) negative carbon excursion. Early intensification coincides with cyclical, progressive aridification and angiosperm proliferation. Re-intensification during climate recovery represents a decoupling of climatic warming and fire, motivated instead by fuel characteristics. Regime persistence alludes to concerning trends in future fire activity under anthropogenic fire suppression. Contemporary wildfire intensification may therefore continue, irrespective of efforts to moderate or withdraw anthropogenic emissions.