Since the early twentieth century, the copper-mining industry on the Zambian and Congolese Copperbelt has moved millions of tonnes of earth and dramatically reshaped the landscape. Nonetheless, mining companies, governments and even residents largely overlooked the adverse environmental aspects of mining until the early 1990s. By scrutinising environmental knowledge production on the Central African Copperbelt from the 1950s until the late 1990s, particularly regarding notions of ‘waste’, this article problematises the silencing of the environmental impacts of mining. To make the environmental history of the Copperbelt visible, this article examines forestry policies, medical services and environmental protests. Moreover, by historically tracing the emergence of environmental consciousness, it contextualises the sudden ‘discovery’ of pollution in the 1990s as a local and (inter)national phenomenon. Drawing on rare archival and oral history sources, it provides one of the first cross-border environmental histories of the Central African Copperbelt.