Rise in dust emissions from burned landscapes primarily driven by small fires

Wildfires reduce vegetation cover and soil biocrust, thus expanding bare grounds susceptible to wind erosion. However, global characterization of post-fire dust emissions has remained qualitative and focused only on landscapes disturbed by relatively large wildfires. Here we apply principles of fluid mechanics to satellite measurements to quantify post-fire dust emissions. We find that 61% of global wildfires at various extents are followed by enhanced dust emissions, injecting 5.6 (3.3–9.2) Tg of dust per year during 2003 to 2022. 95% of the post-fire dust emissions are sourced to small wildfires, which occur more frequently and broadly than large wildfires especially across sparsely vegetated regions. Despite the recent decline in global burned area and a resultant decreasing occurrence of post-fire dust events, the total amount of global post-fire dust emissions has increased by 77% during the last two decades. This elevation in total post-fire dust emissions is attributed to intensifying burning and worsening fire-induced land degradation, which trigger a 155% increase in the intensity of post-fire dust emissions. With an ongoing enhancement of extreme wildfires and synchronized droughts under global warming, our results indicate the emerging importance of post-fire dust emissions globally and regionally. Post-fire dust emissions have increased by 77% globally over the past two decades, and small fires account for 95% of these emissions, according to analysis of satellite observations.