The agricultural sector model SILAS-dyn has been used by Agroscope ART for 10 years for the political advisory of the Swiss agricultural administration. To evaluate the environmental effects of different policy scenarios, a LCA module has been developed, connecting a hierarchical linkage to an existing LCA calculating tool. This lowers the formulation input and simplifies the adaptation of updated environmental models. The results of four scenarios show, through the example of energy use as an environmental impact, that indirect effects, such as energy use in the context of imported concentrates, can influence conclusions significantly. The scenario suggesting an increase of fertiliser prices does not change the results significantly, whereas higher energy prices increase the pressure upon energy-intensive activities.