GHG logo Welcome to GHG, a site devoted to greenhouse gas science and research

Carbon dioxide Sources - Biomass Burning

Exact carbon dioxide emissions from biomass burning are difficult to quantify due to a general dearth of information on fire-carbon fluxes and the longer term balance of carbon emissions and uptake by regrowth of vegetation.

Indeed, in savanna regions of the world, burning is often carried out every few years to promote regeneration of the vegetation. Large amounts of carbon dioxide are produced, but in many cases the subsequent regrowth and carbon dioxide uptake of savanna areas means that the net emission of carbon dioxide is much reduced or completely negated.

Biomass burning is, then, an important short term source of carbon dioxide. In the longer term it can actually contribute to a net carbon sink in the form of relatively stable 'black carbon' in the soils where burning has taken place.

Human Impact

Though fires caused by lightning strikes have, and still do, account for some large biomass burning events, the activities of man in the last 100 years have dwarfed carbon dioxide emissions from such natural biomass burning.

Huge areas of woodland and grassland are periodically burned for land clearance, with this change in land use often reducing the size of the carbon sink and having the net effect of increasing concentrations of carbon dioxide in the atmosphere. See Carbon dioxide Sources - Land use.

Additionally, wood burning as a domestic fuel source and for charcoal production release significant amounts of carbon dioxide on a global scale. Accidental fire and arson account for further large scale biomass burning events each year around the world.

Potential for control

The uncontrolled way in which most biomass burning happens means that the only real route to reducing emissions from this source is to reduce the amount of burning itself. Some biomass burning is required if environments such as the savanna are to be retained, but it is the large scale destruction of forest areas for cash crop agriculture and urban spread which stand out as areas to be tackled.

Controlled biomass burning is currently being developed as an alternative to traditional fossil fuel energy production methods, with power stations fuelled by wood chips and the like already a reality. By making use of a renewable resource, like pine wood chips these biomass power stations are able to have a much reduced net greenhouse gas impact compared to equivalent coal, oil and gas fired power stations.

Contact the Author  •  GHG Online Home  •  Copyright  •  Content disclaimer