Responses of surface radiative balance to wildfires differ across ecosystems

Wildfires alter land surface albedo and temperature, modulating the radiative budget and climate. Previous studies have predominantly reported enhanced shortwave absorption induced by post-fire surface darkening over forests. Here, using two-decade (2001–2020) satellite observations of wildfires, we show that post-fire summer surface albedo and radiative balance shifts vary significantly across ecosystems. Broadleaf forests and grasslands exhibit a brightening effect, because the exposure of bright soils and rapid vegetation regrowth outweigh the deposition of dark carbonaceous residues. The post-fire surface brightening then amplifies the warming-driven radiative cooling. Conversely, in needleleaf forests, shrublands, and savannas, post-fire surface darkening increases shortwave absorption, yet warming-driven longwave radiative losses remain dominant, leading to net radiative cooling. Surface radiative fluxes exhibit high sensitivity to fire size in mid-to-high latitude regions driven by distinct fire-ecosystem feedbacks. Therefore, the ecosystem heterogeneity must be considered when assessing the effects of wildfires on the surface radiative budget and climate.