Potential for Increased Use of Secondary Raw Materials in the Copper Industry as a Countermeasure Against Climate Change in Japan

The copper industry faces serious challenges in achieving the dual goals of mitigating climate change and developing a circular economy, as the increased use of secondary raw materials could increase CO₂ emissions during the smelting stage. This study aimed to examine the possibility of increased use of secondary raw materials (copper scrap and waste from electrical and electronic equipment (WEEE) substrates) in the Japanese copper industry as a countermeasure to climate change. We comprehensive analyzed the changes in CO₂ emissions and costs associated with increased use of secondary raw materials compared to the use of primary copper resources by establishing an intensity at each stage within the system boundary. The analysis results established that CO₂ emissions can be reduced but costs may increase, and that purchasing carbon credits is economically more advantageous. It was also established that the results will vary depending on how CO₂ emissions and costs are allocated because multiple metals can be recovered from WEEE substrates and that the carbon footprint of all‑copper allocation will be significantly lower in the future because of the expected development of decarbonization technologies, including transportation. The study results indicate the potential of the copper industry to expand its use of secondary raw materials from a climate change perspective.