The current El Niño event has had a dramatic impact on the amount of Indonesian biomass burning and subsequent greenhouse gas emission. We have used satellite observations of CH₄ and CO₂ of these fires to probe aspects of their chemical composition. We show large enhancements in the amount of these species, due to the fire emissions. The ability to determine large-scale emission ratios from space allows the combustion behaviour of very large regions of burning to be characterised and understood.