3. Material balances at national level

In order to be able to make effective decisions from an environmental point of view, a "dematerializing" policy should be based on material balances. These are calculations in physical units (generally in tonnes or kilograms), which aim to describe material flows "from cradle to grave", i.e. including the extraction, production, transformation, consumption, recycling and disposal of materials.

• A number of studies of material balances in different countries have been carried out in recent years, including a major comparative study of Japan, the USA, Germany and the Netherlands [2] .

In this study, we distinguish six main categories of materials contributing to an economy's total material requirements: metals and industrial minerals, construction...