Greenhouse gas emissions from fire and their environmental effects

Presentation at Research Forum of the 2012 Bushfire CRC and AFAC Annual Conference.

Grassland covers an area of approximately 440 million hectares in Australia. Fires are a major natural disturbance in grasslands and can occur on an annual basis under some conditions. Both the northern and southern Australian seasonal bushfire outlook for 2011-2012 predicts above normal activity due a large increase in grass coverage caused by heavy rains experienced during 2011. During the process of combustion, carbon dioxide, carbon monoxide, volatile organic compounds, particulate matter and other greenhouse gases are emitted. Emissions of these gases and particulates have great significance for climate and smoke management in relation to air quality and human health. Emissions from fires in tropical and subtropical grasslands, savannas and shrublands have been well documented throughout much of the world, including Australia. However, little information is available on the emissions of these compounds from fires in the temperate grasslands, savannas and shrublands that extend north-south across Queensland, New South Wales and Victoria between the arid interior and the temperate forests to the east. In this study, we compare laboratory measurements of emissions of carbon dioxide, carbon monoxide, and volatile organic compounds from commonly occurring and widespread grass species from the Northern Territory to those from the Australian Capital Territory, in relation to measures of their flammability. These results can be used to inform occupational health and safety requirements and in fire behaviour and air quality modelling.