Kaba, TasissaGetu, Abeba2018-07-112023-11-102018-07-112023-11-102014-02http://etd.aau.edu.et/handle/12345678/7916Global climate change has increasingly gained worldwide attention. The concentration of greenhouse gases in our atmosphere is becoming an issue of increasing concern. To address this problem, it is believed that examining greenhouse gas emissions from different sources is important .Quantification of greenhouse gas emissions from composting facilities is necessary to quantify actual emissions from these systems and which requires a life cycle (cradle to grave) approach. This thesis identifies, quantifies, evaluates and recommends the environmental impact (global warming potential) associated with the flower farm waste composting process using life cycle analysis (LCA) according to ISO14000(2004). The system considered in this study include receipt of source from the farm , transport to the compost production area , production of mature compost and application of compost to a soil for subsequent agricultural application by planting a plant .Under composting emission (Etotal);Transport emission (Te), Process emission (Pe) and Fugitive emission (Fe) were the three Composting system emissions. The result demonstrates that from the three emission categories, transportation is the highest emitter with 59% CO2 eq than fugitive and process emissions. The results for CO2, CH4, and N2O indicate that CO2 is the most significant contributor in all three emission categories with values of 145.26 kg/ton for transport emissions, 90.75 kg/ton for fugitive emissions, and 11.18 kg/ton for process emissions. Compared to CO2 the contributions of CH4 and N2O are insignificant with values running from 0 to 8.09E-03 for CH4 and 0 to 3.66E-03 for N2O. In general composting emission (Etotal) the benefit of post application impact (Btotal) and the Compost Emission Reduction Factor (CERF) became 249.403 kg CO2 eq, 653.44 kgCO2eq and 404.037 CO2eq per ton of feedstock respectively. The results of this study indicates significant environmental benefits arise from the commercial composting system, including net greenhouse benefits, even where the compost is transported significant distances (200kms radius) for agricultural application. Key words: greenhouse gas emissions, global warming potential, cradle to grave, fugitive emission, Transport emission, Process emission, Composting emission, Emission Reduction FactorenGreenhouse gas emissionsGlobal warming potentialCradle to graveFugitive emissionTransport emissionProcess emissionComposting emissionEmission Reduction FactorThesis