Quantifying GHG Emissions From Terrestrial Ecosystems In Africa – The Crucial Role Of Livestock Systems

Abstract:

Knowledge on GHG fluxes from terrestrial ecosystems in Africa remains limited. Published field trials on soil GHG fluxes are summarized in approx. 10 research papers. Emissions related to livestock production, which are dominating most current estimates, rely on modelling work. Thus, uncertainties for African GHG fluxes are likely the highest at continental scale. Even though total GHG fluxes from agricultural soils seem to be low (insufficient fertilizer use/ soil degradation) the opposite might be true for livestock systems. Emissions per kg edible milk protein in SSA are a magnitude higher as for Europe (>100 kg CO_2eq kg^-1). Differences are related to feed intake, quality and availability, species and breeds, etc. Besides, handling of animal wastes is often less sophisticated, resulting in high nutrient losses and GHG fluxes. Estimates remain unconstrained, since in-situ measurements are missing and emission factors, developed elsewhere, are applied without verification to the African situation. To support African countries to improve emission reporting, to improve productivity of the agricultural sector while minimizing GHG fluxes and to allow them to play a vital role in emission trading, , requires to build in-continent research capacity. The International Livestock Research Institute (ILRI), has recently established a state-of-the art GHG laboratory in East Africa, which is envisioned to build a knowledge hub for environmental research. First measurement results indicate that EF for excreta applications to rangelands might be largely overestimated, mainly due to its rather low N concentrations. On the other hand, EF for ruminant CH₄ emissions might be strongly underestimated, since those do not consider that livestock is often held at sub-maintenance levels. Thus, an international initiative is needed to support African countries to learn about land based GHG fluxes and to build research capacity. When do we start?