Thematic maps of active fires or burned areas derived from low resolution remotely sensed data are widely used as an input for the estimation of the atmospheric emissions due to biomass burning. The present work considers three of the global products available for year 2000: two burned area datasets (GBA2000 and GlobScar) and one active fires dataset (World Fire Atlas) and analyses the relative agreements and disagreements in terms of areal extents and geographic location of the fire activity. The intercomparison of the three datasets shows that, while there is generally a good spatial agreement, the disagreement in terms of areal estimates is major. Without a quantitative validation and calibration using high resolution data, the uncertainty of the areal estimates significantly increases the variance of the estimation of atmospheric emissions.