UC Berkeley

Global climate mitigation imperatives are driving contested transformations across riverine and forested environments in the Global South, reshaping long-established patterns of resource use and flows of wealth. With two hydropower dams in place, plans for fifteen more, and an expanding mosaic of protected areas, Colombia’s Upper Magdalena River (UMR) region reveals the tensions embedded in this green restructuring of capital accumulation. This dissertation examines the formation of a green accumulation frontier in the UMR, tracing how projects advanced in the name of climate mitigation and sustainability have transformed land–water relations, agrarian livelihoods, and justice-oriented struggles. Based on a historically and ethnographically grounded analysis, I trace the entangled historical trajectories, environmental conflicts, and uneven geographies that underpin this frontier-making process. How and in what ways does green capitalism take root in and through the Upper Magdalena River Basin? Drawing on critical agrarian studies, environmental justice, and political ecology, I argue that green capitalism cannot be reduced to a market-driven response to the climate crisis. Rather, it takes root through a frontier-making process that rearticulates older patterns of accumulation—including dispossession, extractivism, and devaluation of socio-environmental reproduction—while developing new mechanisms for enrolling human and non-human natures into global value circuits. In doing so, it generates the socio-environmental contradictions that lay the groundwork for its own contestation and instability. This dissertation moves beyond the single-sector or single-resource analyses that dominate critical scholarship on green capitalism by developing an analytical framework that connects hydropower, conservation, and REDD+ as intersecting moments within the UMR’s green accumulation frontier. I draw on seventeen months of ethnographic and community-engaged fieldwork conducted between 2022 and 2025 across six UMR communities. I combine participant observation, semi-structured interviews, and extensive archival and oral history research with hands-on collaboration with fisher and peasant communities to create collective decision-making spaces around climate policy. This methodology included close collaboration with agrarian, anti-dam, and environmental justice organizers, as well as immersive participation in multi-stakeholder forums on climate action. Through these engagements, I trace how struggles across land reform, riverine management, and forest conservation reveal how green accumulation frontiers are both constituted and contested in everyday life. The dissertation develops across three papers. The first traces the history of hydropower development in the UMR and argues that clean energy emerged as a reactionary project against agrarian reform struggles, producing what I call a terraqueous takeover: the territorialization of a new socio-environmental order through the transformation of land–water relations. The second paper, co-authored with Michael Mascarenhas, examines the role of force in environmental justice struggles, showing how organized resistance disrupted and ultimately derailed the expansion of a hydropower-led green frontier. The third paper, co-authored with Sergio Carvajal, analyzes REDD+ in the river’s forested headwaters, arguing that carbon-centered accumulation depends on rent relations, the devaluation of socio-environmental reproductive labor, and the conversion of forests into means of mitigation for fossil-fuel production elsewhere. This dissertation provides a grounded and multiscalar account of the emergence of green capitalism and its associated conflicts in the UMR. It shows that green capitalism is not a cohesive project but rather a variegated formation that articulates global climate mitigation imperatives with place-based histories of dispossession, conservation, and socio-environmental struggle in the production of uneven and unstable green accumulation regimes.