The system expansion approach takes into account all processes
that are affected by a change in the production of a product. By an
increase in the production of sugar, the co-production of molasses
is also increased. In order to avoid allocation between molasses
and sugar, resource use and emissions associated with molasses
are included in the sugar production. As a way to compensate for
this, the sugar cane system is expanded to include the avoided production
of animal feed elsewhere. The assumption behind this is
that the increased production of molasses resulting from increased
sugar production will reduce feed production in other systems. In
light of this approach, the environmental burdens associated with
molasses introduced to ethanol production are put equal to those
resulting from the production of some feed crop(s) to replace
molasses as an energy supplement for cattle