Ex-post evaluation of GHG emissions and energy consumption in organic and conventional meat SHEEP farms in France over 26 years

The environmental impact of livestock is an important issue, and organic farming (OF) is particularly questioned about greenhouse gases (GHG) emissions. This study aims at comparing GHG emissions and non-renewable energy consumption in meat sheep production, in OF and conventional farming systems. These two criteria have been calculated ex-post on 1261 French year-farms monitored over 26 years. The functional unit used is the carcass weight and allocation between meat and wool is mass based. Regarding GHG emissions, the results show that organic farms emits 5% less GHG than conventional ones, with a higher proportion of methane and less indirect CO2 associated to less inputs use. Given the methodological difficulties, it is hard to argue if carbon sequestration in soil is different between OF and conventional. For non-renewable energy, there is no significant difference between OF and conventional farms, due to compensation (more mechanization and less concentrates and fertilizer purchased). Note the great variability in the results, both in OF and conventional farms. The two main explanatory factors are ewe productivity (for GHG) and forage self-sufficiency (energy consumption).