Natural causes of fires are lightning and spontaneous combustion of dry vegetation. After the dry season, the undergrowth is rich in twigs and other dry biomass that represent a dangerous accumulation of flammable material, as do abandoned crop fields.

Every year many hectares of forest and savannah are destroyed all around the world, with consequences on the entire ecosystem (human life, animal/plant habitats, carbon cycle disturbance, property loss etc.) Prevention and early warning are the only means of reducing these costs. Satellite data can rapidly provide a general overview of the situation over large areas of terrain, detect fires, identify risk areas and finally assess the damage by mapping the extent of the burned areas.

The ATSR World Fire Atlas provides monthly global fire maps made from night time data provided by the Along-Track Scanning Radiometer instruments (ATSR-2 onboard ERS-2 and AATSR onboard ENVISAT). The maps are generated monthly, and cover the period from September 1995. Another useful satellite is Landsat 5 with its Thematic Mapper (TM) instrument that provides very impressive colour images covering an area 180x180 km with 30 m of resolution, where it is possible to distinguish fire-damaged areas and active fires.