Protected areas are a cornerstone of global conservation policy, yet those located in remote regions are often viewed as inefficient because they protect forests under little immediate threat. This view assumes static institutions and stable land-use patterns. We show instead that the conservation value of protected areas is dynamic and can rise sharply when environmental governance weakens and deforestation pressure expands. Studying Brazil’s Amazon rainforest during two major institutional shocks—the 2012 Forest Code reform and the 2019–2022 Bolsonaro administration—we find that protected areas prevented large increases in

deforestation during periods of institutional decline. Using quasi-experimental evidence from 2004 to 2022, we show that deforestation surged outside protected areas but remained stable within them, particularly in remote regions. Areas previously considered non-additional thus revealed a latent conservation value, functioning as critical bu”ers against governance erosion. These findings have important implications for global conservation strategies and 30×30 commitments.