The International Journal of Life Cycle Assessment
Marlies A. Thomassen et al.
Animal Production Systems Group, Wageningen University and Research Centre, P.O. Box 338, 6700 AH, Wageningen, The Netherlands
Published: 01 May 2008

  • For an average Dutch conventional milk production system, an ALCA (mass and economic allocation) and a CLCA (system expansion) were performed.
  • ALCA describes the pollution and resource flows within a chosen system attributed to the delivery of a specified amount of the functional unit (Rebitzer et al. 2004). CLCA estimates how pollution and resource flows within a system change in response to a change in output of the functional unit (Ekvall and Weidema 2004; Rebitzer et al. 2004).
  • Within ALCA, avoiding allocation by using system expansion to handle co-products is optional, while co-product allocation is most frequently used. Avoiding allocation by system expansion, however, is the only way to deal with co-products within CLCA, as it reflects the consequences of a change in production (Weidema 2003).