This study attempts to investigate the economy and sustainability of using biogas in rural Gambia and future strategies towards cleaner energy for cooking. The author also intends to use the diffusion model for uses of low cost resources available to the farmers concerned, comparing the biogas system of other countries like Taiwan, Nepal, Sri-lanka, and India. Domestic biogas installations principally reduce greenhouse gas (GHG) emissions in three ways: by changing the manure management modality; by substituting fossil fuels and non-renewable biomass for cooking (and to a smaller extent for lighting) with biogas, and; by substituting chemical fertilizer with bioslurry. The scope of this thesis is based on the use of cattle-dung for biogas production and is limited to the development of biogas for household purposes and mainly for use as cooking energy source. Worldwide, biogas is being produced using wide ranging biodegradable materials and with equally wide ranges of usage at domestic, communal, commercial and industrial levels. The purpose of this study is to explore feasibility for the country-wide development and usage of biogas for household cooking in The Gambia in other to save our forest. The Clean Development Mechanism (CDM) promotes sustainable development in developing countries by enabling industrialized countries to earn emissions credits from their investments in emission-reducing projects in developing countries. Biogas programmes help reduce the emissions of greenhouse gases, mainly methane. These reductions are obtained by burning biogas instead of firewood, charcoal, kerosene, dried animal waste or agriculture residues for their domestic cooking and lighting energy needs.