Harnessing methane generated from livestock manure in Ghana, Nigeria, Mali and Burkina Faso

Methane emission from livestock manure is increasingly contributing to the global green house gas emissions. In this paper the methane emission from cattle, pig, sheep, goat and chicken manure in four West African countries; Nigeria, Ghana, Burkina Faso and Mali were estimated. A systematic estimation of the methane emission was done based on the livestock production projections by FAO from 1998 to 2008 and guidelines provided by the Intergovernmental Panel on Climate Change (IPCC). During this period, cattle were found to have emitted more methane followed by pigs, goats, sheep and chicken in that order. A total of about 845 Gg of methane was emitted by the livestock during the period of which cattle contributed about 40%, whereas pigs, goats, sheep and chicken contributed 21.2%, 18.7%, 13.1% and 6.6% respectively. The methane emission from manure management in these countries increased from 64.1 Gg in 1998 to 90.5 Gg in 2008, with an annual growth rate of 3.4% y⁻¹. The methane estimated from livestock manure over the period was shown to be consistent with the linear group model which predicts that in 2018, 2.4 Mt CO₂-eq will be emitted increasing to 3.0 Mt CO₂-eq in 2028 if the mechanism of manure management remains unchanged. This paper reveals that generating methane from the manure produced by the livestock under controlled conditions could supplement the energy needs, increase Gross Domestic Product (GDP) and consequently reduce the direct impact of methane on climate change.