Direct greenhouse gas emissions of the South African small stock sectors
AbstractThere are increasing concerns about the impact of agriculture and livestock production on the environment. As a result, it is important to have accurate estimations of greenhouse gas (GHG) emissions if reduction measures are to be established. In this study the direct GHG emissions from South African sheep and goats during 2010 were calculated. Calculations were done per province and in total. The Intergovernmental Panel on Climate Change (IPCC) methodology, adapted for tropical production systems, was used to calculate methane (CH4) and nitrous oxide (N2O) emissions on a Tier 2 level. Small stock is a key methane emission source in the South African livestock sector, and is responsible for an estimated 15.6% of the total livestock emissions. Small stock contributed an estimated 207.7 Giga gram (Gg) to the total livestock methane emissions in South Africa in 2010, with sheep producing 167 Gg and goats producing 40.7 Gg. Calculated enteric methane emission factors for both commercial and communal sheep of 8.5 kg/head/year and 6.1 kg/head/year, respectively, were higher than the IPCC default value of 5 kg CH4/head/year for developing countries. A similar tendency was found with goat emission factors. The highest sheep and goat methane emissions were reported for the Eastern Cape province, primarily because of animal numbers.
Keywords: Greenhouse gas, methane, nitrous oxide, sheep, goats