Escalating Wildfires in Siberia Driven by Climate Feedbacks Under a Warming Arctic in the 21st Century

Abstract

Siberian wildfire is of paramount importance in the carbon cycle and climate change as it is a major disturbance in the pan-Arctic ecosystems. In recent decades, the Siberian wildfire regime has been shifting; however, less is known about its process-based feedback mechanisms. By integrating in-situ and satellite observational data sets as well as chemistry-climate coupled modeling, we find that central Siberia has featured the most prominent wildfire escalation during the past two decades, which is closely related to hydrological drought with decreasing rainfall and drying soil under a fast-warming Arctic. Furthermore, fire-emitted aerosols compound the increasing wildfires via serving as cloud condensation nuclei and suppressing precipitation, forming self-amplifying feedback. As the Arctic warming is projected to continue, wildfires are estimated to more than double by the end of this century. This work highlights the great importance of fire risk management based on a fundamental scientific understanding of the complex climate system.