Amid fossil-fuel-driven climate change, finding sustainable replacements for everyday fuels and materials made from petroleum—from plastics to synthetic fabrics—has been a pressing concern for decades. Plant-based products, enabled by biotech, are one solution. However, “plant-based” or “bio-based” often generically stand in for ethical and sustainable consumption, while the social and environmental impacts of bioproducts can in fact replicate uneven structures of oppression. This dissertation theorizes such contradictions through studying scientists’ efforts to make biofuels, bioplastics, and other bioproducts from sugarcane in Brazil. If between the 16th and 20th centuries Brazilian sugarcane was located at the nexus of plantation and factory, in the 21st century it is squarely located at the nexus of industrial-agricultural field, flexible factory, and biotech laboratory. Complementing the extensive Brazilian scholarship on present-day sugarcane labor, this dissertation looks at another increasingly important site of sugarcane production: the production of knowledge in the lab. I argue that sugarcane-based renewables often reproduce petro-extractivism under the guise of sustainability, yet scientists’ practices also open other possibilities. This dissertation draws on ten years of ethnographic fieldwork and experimental cataloging methods (what I call a sugar library) in São Paulo, Brazil and California, US.

I offer changeways as the dissertation’s key conceptual intervention: changeways are particular stories of broader social change embodied in patterns of practices, relations, materials, and molecules surrounding sugarcane-based bioproducts. Put differently, changeways are genres of socio-material change. Each chapter is guided by a key entry from my sugar library in order to analyze a different changeway: flexible change, substitutive change, generic change, sucro change, and excusive change. The first three tend to reproduce petro-extractivism, despite renewable ideals. When sugarcane is transformed into bioproducts, often another important transformation happens too: petro-capitalism’s culpability in climate crises is alchemically transformed into the idea that capitalism is the only way to solve climate change. However, the latter two changeways offer possibilities within and beyond petro-capitalism through challenging how raw materials are conceived in the first place, and challenging the very instrumentality of scientific knowledge production. In all, changeways name how scientists’ technical practices lay the molecular foundations for various ideologies of change in an era of climate change. The dissertation thus provides concepts for STS, environmental anthropology, and energy humanities around contemporary convergences of natural resource extraction, scientific knowledge production, and social transition.