Recurrent episodes of land and forest fires have been a feature of Southeast Asia’s ecology since the Pleistocene Age. These wildfire episodes are made possible by periods of reduced precipitation intense enough to make even rainforests dry enough to burn. During the Ice Age, extended periods of minimal rainfall occurred in Southeast Asia, making large areas of the region vulnerable to fire. More recently, the recurring climatological disturbance known as the El Niño-Southern Oscillation (ENSO) has repeatedly set the stage for large-scale wildfires in the areas that today comprise the member states of the Association of Southeast Asian Nations (ASEAN).