This work evaluates sugar cane agro-ecosystems, taking into account both the environmental implications and the use of natural resources as production factors. The costs are estimated in financial and energetic measures, and three scenarios are established. The results indicated a increase from 4.02% to 4.12% of higher costs due to the accounting of externalities and that it is possible to achieve a profitable production in a sustainable ecosystem. They also show that the differences of the energy amount, counting or not the externalities and the different costs of a sustainable production, remain small and that the sustainable perspective will only be attractive if it is based upon the social definition of higher values to the natural environment.
Agro-ecosystems; environment; energy and agriculture; sugar cane