Biochar – a carbon-rich product used as a soil conditioner – is among the more recent technologies in environmental governance. In the spirit of ecological modernisation, biochar is claimed to deliver multiple benefits for soil fertility and climate change mitigation. However, biochar has a long history. It was inspired by Terra Preta, a highly fertile soil of anthropogenic and pre-Columbian origin found in the Amazon. This article uses discourse analysis to explore how the Terra Preta and biochar concepts have been articulated over time and what environmental discourses they resonate with. Our analysis shows that over time, the concept of biochar has slowly become disconnected from Terra Preta. While the concept of Terra Preta continued to be closely connected with Amazonian nature, archaeology and indigenous culture, biochar gained international traction and became embedded in ecological modernisation discourse. The different articulations of these concepts in fact represent different conceptualisations of human–nature relationships. We suggest the rich and intricate history of biochar and its connection with Terra Preta is key to understanding how the concept changed throughout the years, how it was influenced by international environmental discourses and how its underlying assumptions will determine who might benefit the most from biochar.