Future copper loads into the European aquatic environment

The green transition is likely to lead to increased demand for copper, which raises the question whether and to what extent copper loads to the environment will also increase. This research was aimed at predicting the changes in copper loads to the aquatic environment in the European Union from all of the main sources up to 2050. Initially, an updated baseline source apportionment was calculated, giving a total current copper load for the European Union of 13,048 tonnes per year. A literature review, combined with input from industry experts, allowed the projection of loads to 2050. Projections were developed based on predicted changes in population, transport, agriculture, aquaculture, sewage treatment plant inputs and discharges, climate change (affecting rainfall and erosion), and changes in regulation (both recent and potential). By 2050, there was a predicted increase of copper loads to the European Union aquatic environment to 16,193 tonnes per annum, approximately 24%. This was mostly driven by higher loads of copper-based antifouling paints leaching from more marine shipping and from copper in brake linings owing to increased vehicle use (domestic and commercial). Reductions were expected for copper loads from landfills, combined sewer overflows, disused mines, sewage effluent, antifoulant use in aquaculture, and septic tanks, largely owing to tightening of environmental legislation. There are clear limitations and uncertainties around these projections, particularly due to the unpredictability of future regulation. This study shows that increased copper use in the green transition will not trigger correspondingly greater copper loads to the environment, largely owing to the copper being associated with wiring and motors with no direct pathway to water. Rather, future changes are likely to be driven by specific uses of copper associated with increased transport (marine and vehicular) that have more direct pathways to the aquatic environment.