Functional unit for systems using natural raw materials

The necessity of a functional unit, which considers the equality of all benefits, is underlined especially for systems using such natural raw materials as wood. The example of identifying the ecological optimal extent of paper recycling is therefore examined by using the data of 11ASA [1]. It can be shown that the calculated quantity of the ecological optima particularly depend on the selected model of the comparison. In general, a functional unit of LCA should be based on a model which considers all benefits of the compared systems. The additional benefits of forests have to be taken into account as well. Otherwise, no statement concerning the ecological optima is possible.