Significant Effective Radiative Forcing of Stratospheric Wildfire Smoke

The radiative forcing (RF) of volcanic sulfate is well quantified. However, the RF pyrocumulonimbus (pyroCb) smoke with absorbing carbonaceous aerosols has not been considered in climate assessment reports. With Community Earth System Model, we studied two record-breaking wildfire events, 2017 Pacific Northwest Event (PNE) and 2019–2020 Australian New Year event (ANY), that perturbed stratospheric chemistry earth's radiation budget. We calculated a global annual-mean effective (ERF) −0.04 ± 0.02 −0.17 W/m2 at top atmosphere (TOA) for PNE ANY, respectively. complexity longwave led to an uncertainty about 50% ERF TOA among models. found modeled from was 70%–270% more negative than mass-equivalent aerosol, highlighting its important role