Furthermore metals are not renewable, although their reserves may last for several hundred years. Therefore, in general terms, in order to reduce the environmental impacts of metals, the most straightforward criteria would be to reduce the amount of metals used in favour of wood (-based) materials. Increasing the share of recycled materials in metal also considerably reduces the energy needed to produce steel and aluminium. For example the energy needed to produce 1kg of 100%-recycled aluminium is approximately 10% of that needed for the production of primary aluminium. Beyond energy savings this also reduces the impacts of mining described above, and reduces final waste streams. Therefore the use of.
