Indonesia — Who is responsible when smoke fills the sky? Do people who setagricultural fires deserve the blame, or are natural cycles the real culprit?The correct answer may be yes. In the case of wildfires in Indonesia,human activity and natural cycles likely conspire to create devastating fireseasons. Fire has long served as a cheap, easy means of clearing land for cropsand tree plantations. While some fires die out before causing extensive damage,others burn out of control, invading nearby forests. The deciding factor inwhether human fire activity will escalate into catastrophic burning in Indonesiaappears to be may be the occurrence of El Niño.
Among other gases, fires emit carbon monoxide, making the gas a good indicator of fire-related pollution levels. These images compare carbon monoxide concentrations at an altitude of about 3 kilometers in an El Niño year (November 2006) versus a non-El Niño year (November 2005). The data were collected by the Measurements of Pollution in the Troposphere (MOPITT) sensor on NASAs Terra satellite. Values range from little or no carbon monoxide (blue) to 300 parts per billion (red). In some areas, persistent cloud cover or gaps in the satellite orbit prevented data collection, and these areas appear light gray over land, or dark gray over the ocean. Compared to 2005, November 2006 shows much more carbon monoxide pollution over Indonesia and its neighbors.
This connection between Indonesian carbon monoxide levels and Niño was documented by group of researchers from the National Center for Atmospheric Research, the National Oceanic and Atmospheric Administrations Earth System Research Laboratory, and Toronto University. The research team studied carbon monoxide levels since the start of the MOPITT data series in 2000 and found that fires were worse during El Niño events in 2002, 2004, and 2006. El Niño worsened fires by reducing rainfall and drying out forests on Borneo and Sumatra. In the drought conditions, agricultural fires burned out of control.
Forest fires can lead to significant deforestation, especially in placesalready degraded by logging or previous fire. There are also concerns about thestability of peat deposits in the regions swampy, lowland forests. Peatthicklayers of partially decayed vegetationis both extremely flammable and arepository for carbon. Peat burning releases not just carbon monoxide, but alsocarbon dioxide, a greenhouse gas.