Transforming trash: reuse as a waste management and climate change mitigation strategy
- Author(s): Vergara, Sintana Eugenia
- Advisor(s): Nelson, Kara L
- et al.
Waste reflects the culture that produces it and affects the health of the people and environment surrounding it. As urbanization and waste production increase on a global scale, cities are faced with the challenge of how to manage their waste effectively to minimize its negative impacts on public and environmental health. Using waste as a resource can offer a variety of environmental benefits, including climate change mitigation, though these benefits are variable and uncertain. My work begins with an overview of the relationship between solid waste and the environment, focusing on two trends over time and space: regionalization and formalization of waste management. Recognizing that appropriate waste management must be determined locally, I then focus on two places, one in the Global North, and one in the Global South, whose waste production and management differ tremendously, and quantify the climate benefits from reuse strategies at different scales using life-cycle assessment (LCA). In California, USA, where waste production and access to technology are abundant, I ask: how can the state minimize the greenhouse gas (GHG) emissions from its municipal waste management? I conclude that source reduction and anaerobic digestion are the methods by which CA could most greatly and robustly reduce its waste emissions. I also find that waste LCA results are very sensitive to model assumptions, about system boundary, landfill behavior, and electricity generation, though the emissions from source reduction are robust to these inputs. In Bogotá, Colombia, where the municipal government is in the process of modernizing their recycling system, I ask: what are the GHG emission implications of this modernization? I find that the unregulated recycling system is more financially sustainable, more socially inclusive, and abates more greenhouse gas emissions than does the municipal system. The municipal system, on the other hand, conforms to aesthetic visions of a modern city, and provides workers with steady employment and benefits. A hybrid model could combine the incentives and efficiency of the informal system with the working conditions of the municipal one. In Bogotá and in California, modes of reuse - technologies or behaviors that use waste as a resource - offer waste management, environmental and climate benefits.