Domestic biomass combustion and associated atmospheric emissions in West Africa

Biofuel is the main source of energy for cooking and heating in Africa. In order to estimate the consumption of this resource at a regional level, a database with a spatial resolution of 1 degrees latitude by 1 degrees longitude of the distribution of the amounts of fuel wood and charcoal annually burned in West Africa has been derived. Chemical emission factors for fuel wood, for charcoal burning, and for charcoal fabrication measured during two field experiments are then used in conjunction with this database to produce a second 1 degrees latitude by 1 degrees longitude database of the emissions due to domestic fires for the region. A comparison of these emissions from domestic fires with those of savanna fires, the dominant form of biomass burning in tropical Africa, shows that the relative contribution of the wood fuel (i.e. fuel wood and charcoal) combustion is important for CH4 (46%), CO (42%), and nonmethane hydrocarbons (NMHC) (44%), less so for CO2.(32%). This source of biomass burning has a different spatial and temporal distribution than that of savanna fires and represents an atmospheric background noise throughout the year, whereas the savanna fires occur during a limited season.