Mineral demand is rising worldwide for renewable energy technologies (e.g. solar, wind and batteries), and other major infrastructure such as transport, data centres and digital devices. At the same time, controversy and complexity mean that building new mines is difficult, while metal recycling remains underdeveloped. These pressures are driving companies to intensify and expand extraction at existing “brownfield” mines – operating deeper, larger mines, for longer periods. Yet the extent of this shift, and how it contributes to accumulating social and environmental risk, remains elusive at global scale. We use more than 20 years of data on mining activity and capital investment to identify 366 brownfield mines that have expanded, with many located in socio-ecologically sensitive areas. Our results support policymakers and practitioners to develop governance frameworks aligned with a future increasingly dependent on rising brownfield mining.

Growing mineral demand and constraints on new mine development are reshaping the structure of global mineral supply. However, the structural mechanism of these changes has not been made visible. Using global mineral production and capital-expenditure data from 1998–2024, we show that production growth increasingly depends on expanding and intensifying existing operations (i.e. “brownfield” mines). We identify 366 brownfield mines and show that many intersect with sensitive socio-ecological contexts, highlighting emerging risks and the need for governance attuned to cumulative impacts and long-term liabilities.

   Link to 3 minute audio overview of the article by co-author Dr Julia Loginova