Volumetric Impact Characterization of the 2025 Palisades and Eaton Fires Using Aerial LiDAR

In January 2025, the Palisades and Eaton fires overtook large swaths of Los Angeles County, covering a combined area of approximately 152 km2, composed of diverse coastal, urban, and forested environments. Aerial Light Detection and Ranging (LiDAR) surveys were commissioned directly following these fires, and compared against previously unreleased foundational LiDAR surveys captured in 2023 and 2024. The timeliness of these surveys presents a unique opportunity to approach large-scale damage characterization metrologically at sub-meter resolution. Cell-based height differencing across 367 million change-detected cells (on a 0.5 m grid) identifies 49.5 km2 of vegetation loss and 1.66 km2 of building footprint destruction in the Palisades fire, and 24.3 km2 of vegetation loss and 1.48 km2 of building footprint destruction in the Eaton fire. From the resulting volumetric loss inventory, we derive bottom-up carbon emission estimates of 255±61 kt C for the Palisades fire and 162±38 kt C for the Eaton fire. The Eaton estimate agrees to within 6% of an independent atmospheric inversion estimate derived from ground-based sensor networks, well within the propagated uncertainty of either method, providing an independent cross-validation, at the total-emission level, between LiDAR-based and atmospheric-inversion approaches to wildland–urban interface fire emissions. This paper details the segmentation and characterization methodology, and coincides with ALERTCalifornia’s public release of all described raw and derivative datasets.