Addressing dairy industry's scope 3 greenhouse gas emissions by efficiently managing farm carbon footprints

Abstract

Corporate climate action is increasingly considered important in driving the transition towards a low-carbon economy. Especially in the food processing industry indirect greenhouse gas (GHG) emissions upstream in a producer's value chain (scope 3 emissions) often represent the largest portion of the GHG inventory. In order to manage those GHG emissions efficiently there is a need for simple GHG calculation models ready for large scale application on supplying farms. The aim of this study is to describe a procedure for the development of a simplified GHG calculation model specific for dairy farms based on detailed GHG emission calculations. The results presented are obtained from a case study of supplying farms of a Bavarian organic dairy. The simplified model shall reduce the number of input parameters significantly while representing the variations in GHG emissions across farms and allowing the quantification of GHG mitigation measures. The median farm carbon footprint (CCF) of the case study farms calculated with the detailed calculation model is 441.7 t CO2e/a (mean number of dairy cows per farm is 57). The total GHG mitigation potential per farm ranges from 6.51 t CO2e/a to 112.29 t CO2e/a. The simplification of the calculation model results in a less complex and time consuming questionnaire covering 57 parameters instead of up to 467 in the detailed model. The total CCF results of the simplified model give highly comparable results to the detailed calculation model (R2 = 99.7% , standard error = 2.3% of the mean CCF). The correlation between the total mitigation potential calculated per farm by the simplified and detailed calculation model is also high (R2 = 98.92%, standard error = 7.0% of the mean total mitigation potential per case study farm). For the quantification of some mitigation measures with the simplified model, attention must be paid to the question whether calculated GHG emission reductions are significantly higher than the standard error of GHG emissions calculated for the relevant life cycle stage. Summarizing the procedure for the development of a simplified GHG calculation model proposed in this paper, leads to a model that meets the defined requirements.