The detection of forest fires and the determination of their parameters have been usually carried out by polar-orbit sensors: AVHRR, (A)ATSR, BIRD, and
MODIS mainly. However, their time resolution prevents them from operating in real time. In contrast, the new geostationary sensors have very appropriate
capacities for the observation of the Earth and monitoring of forest fires, as is being proved. GOES, MSG, and MTSAT are already operative, and they have
led the international community to think that the global observation network in real time may become a reality. The implementation of this network is the aim of
the Global Observations of Forest Cover and Land Cover Dynamics (GOFC/GOLD) FIRE Mapping and Monitoring programme, focused internationally on
taking decisions concerning the research of the Global Change. In this Letter, the operation in real time by the MSG-SEVIRI sensor over the Iberian Peninsula is
studied. On the other hand, the reliability of validation results by means of polar sensors, with a finer spatial resolution, is difficult to analyse due to errors caused
by confused location of fires. This Letter shows that fires detected by means of MSG-SEVIRI can be an useful option in order to estimate burnt areas at global
scale, considering a spatial resolution of 40 km.