Keywords
uncertainty, variability, life cycle assessment, pig production, eutrophication
Start Date
1-7-2004 12:00 AM
Abstract
In a case study of pig production systems we propose a simple quantification of the uncertainty of LCA results (intra-system variability) and we explored inter-system variability in order to produce more robust LCA outcomes. Our quantification of the uncertainty took into account the variability of technical performance (crop yield, feed efficiency) and of emission factors (for NH3, N2O and NO3) and the influence of the functional unit (FU) (kg of pig versus hectare used). For farming systems, the inter-system variability was investigated through differentiating by the production mode (conventional, quality label, organic (AB)), and farmer practices (Good Agricultural Practice (GAP) versus Current practice (CP)) while for natural systems, variability due to physical and climatic characteristics of catchments expected to modify nitrate fate was explored. For the eutrophication impact category, the variability of field emissions contributed more to uncertainty than the variability of building emissions, crop yield and feed efficiency. The influence of the FU on eutrophication results was very important when comparing systems with different degrees of intensification such as GAP and AB. Concerning inter-system variability, differences in farmer practices had a larger effect on eutrophication than differences between production modes. Final
Implications of Uncertainty and Variability in the Life Cycle Assessment of Pig Farming Systems
In a case study of pig production systems we propose a simple quantification of the uncertainty of LCA results (intra-system variability) and we explored inter-system variability in order to produce more robust LCA outcomes. Our quantification of the uncertainty took into account the variability of technical performance (crop yield, feed efficiency) and of emission factors (for NH3, N2O and NO3) and the influence of the functional unit (FU) (kg of pig versus hectare used). For farming systems, the inter-system variability was investigated through differentiating by the production mode (conventional, quality label, organic (AB)), and farmer practices (Good Agricultural Practice (GAP) versus Current practice (CP)) while for natural systems, variability due to physical and climatic characteristics of catchments expected to modify nitrate fate was explored. For the eutrophication impact category, the variability of field emissions contributed more to uncertainty than the variability of building emissions, crop yield and feed efficiency. The influence of the FU on eutrophication results was very important when comparing systems with different degrees of intensification such as GAP and AB. Concerning inter-system variability, differences in farmer practices had a larger effect on eutrophication than differences between production modes. Final
