These data support the manuscript 'Vast ecosystem disturbance in a warming climate may jeopardize our climate goal of reducing CO2 a case study for the megafires in Australian ‘Black Summer'', including megafire CO2 emissions in Australian 'Black Summer' estimated by BBM model and a top-down method. The delta RF simulations by GEOS-Chem RRTMG are also contained. In each separate folder there is a README.txt file as a user's guide. The methodology for deriving the datasets and more information can be found in the manuscript and SI.