Copper (Cu) and zinc (Zn) with their unique propertiesare central for economic growth, quality of life and creation of new jobs. The base-metalproducing sector is, however, under growing public pressure in respect toenergy and water requirements and needs to meet several challenges, includingincreased demand and lower ore grades generally associated with larger resourceuse. The development of technologies for metal production from secondarysources is often motivated by increased sustainability and this paper aims to providefurther insights about one specific aspect of sustainability, namely climatechange. The paper presents a review of carbon footprints (CF) for Cu and Znproduced from primary and secondary raw materials, by analyzing data taken fromscientific literature and the Ecoinvent database. Comparisons are carried outbased on the source of data selected as reference case. In the case of Cu,reduced CF of secondary production is indicated, although there is large datavariation. As for Zn, production of this metal from secondary sources seems to bebeneficial but the number of data and cases to be compared is much smallercompared to Cu. The general variation of data suggests that standardization ofcomparison is needed when assessing the environmental benefits of production inline with the principles of waste valorization, zero waste approach andcircular economy.
