AGRICULTURAL REFERENCE SYSTEMS IN LIFE CYCLE ASSESSMENTS - Economics of Sustainable Energy in Agriculture - page 100

cleared for this purpose. This however, is only one option out of many
possible ones. The exact option chosen must be implicitly defined in the
question on which the LCA is based.
Thus in the example above, the exact and correct question would
not be: 'What would be the environmental consequences of rape seed
production in Germany?', but instead: 'What would be the environmental
consequences of rape seed production in Germany, if it were to replace the
production of maize and this maize were then to be produced in South
America on cleared rain forest areas?'.
If instead of clearing rain forest, the maize were to be produced on
sites where otherwise for example sugar cane would be cultivated, then
obviously this chain would continue. We define the alternative land use on
the area directly under concern as the 'reference area'. The reference
system includes this area but in addition it includes all the land use changes
that arise indirectly, as well as all emissions from transport and other
processes ( e.g. different production methods etc.). Thus it can be deduced
that the reference system is closely connected to the exact question on
which the LCA is based. If the question is formulated precisely, then the
reference system is automatically defined.