Satellite image of thick smoke in Borneo from numerous fires, most of them likely started by the "slash-and-burn" technique of local deforestation for agriculture, though logging activities may have started the fires accidentally. The exceptionally heavy smoke is caused by the burning of the peat in the peat swamp forests of the area and it results in air pollution, disrupts air traffic, and significantly adds to greenhouse gas emissions.Image: Jacques Descloitres, MODIS Land Rapid Response Team