Tropical rainforests carry the highest biodiversity with more than 90% of all plant and animal species of the world, although they cover only 7 % of the land surface. Tropical rainforests are a precious natural resource, are home for millions of indigenous people and furthermore are of great importance for regional and global climate.

In comparison to boreal and Mediterranean forests fire in wet tropical regions seems to be a contradiction. Tropical rain forests are an extremely humid biota characterized by a minimum of 2000 mm of rain per year. Under natural, undisturbed conditions fire is a very rare event. However, in recent years large tracts of rainforest were heavily exploited resulting in a severe degradation of the ecosystem. Selective logging and slash and burn agriculture opened up the forest canopy and made the vegetation more susceptible to fire. Large scale conversion projects led to decreased humidity and rainfall, which in turn increased the probability of forest fires as they occurred recently in South America and SE-Asia during the 1997/98 El Nino episode.