Environmental Impacts of Material Systems

Life cycle assessment recycling allocation methodology

LCA practitioners struggle to accurately allocate environmental burdens of metals recycling, including the temporal dimension of environmental impacts. To further the discussion of this issue, we analyzed multiple recycling allocation methodologies for calculating aluminum greenhouse gas emissions, including the recycled content (RC) or cut-off approach which assumes that demand for recycled content displaces primary production and end-of-life recycling (EOLR) which assumes that post-use recycling displaces primary production.

Anthropogenic material cycles

Previous research utilized a key tool of industrial ecology – material flow analysis – to quantify the anthropogenic flows of industrial metals. Throughout their life cycle, we quantified all major flows of chromium and silver, from mining through processing, product manufacture, use, and disposal or recycling.  These studies were multi-level: metal cycles were created for over sixty countries, eight world regions, and the planet as a whole.  The benefits of such research on anthropogenic metal cycles include the comprehensive quantification of human-induced releases of metals, a deeper understanding of the resource productivity of these metals across all end uses, and a quantification of the addition to metal stocks.