| dc.description.abstract | Annual atmospheric levels of carbon dioxide (CO2) have risen from 11 Gt in 1960s to 36.6 Gt in 2023. In order to mitigate the global warming impact, the implementation of carbon capture, utilization, and storage technologies (e.g., negative emission technologies (NETs)) is crucial to prevent rising carbon emissions and achieve climate stabilization. NETs encompass various strategies including carbon capture and storage with bioenergy, direct air capture, enhanced weathering, reforestation, afforestation, oceanic sequestration, agricultural practices, and biochar. Recent advancements also have introduced novel carbon removal approaches, such as chemical looping combustion for CO2 capture, the use of CO2 in beverage carbonation, and its storage in basalt and ultramafic rocks through carbon mineralization. However, the environmental and human health implications associated with the social perspective of increasingly emerging CCUS technologies and carbon-negative products have yet to be thoroughly analyzed. Therefore,
employing systems thinking and a holistic approach to evaluate the sustainability performance of these technologies and products is essential for informed decision-making.
One way to estimate environmental impacts is by utilizing the life cycle assessment (LCA) methodology. The first LCA (chapter 2) study highlighted significant research gaps through a literature review on enhanced weathering for carbon sequestration, specifically focusing on wollastonite. It found that natural wollastonite is preferable for carbon capture due to its lower environmental and health impacts compared to synthetic forms, which showed a dramatic increase in these impacts when transitioning from natural sources; however, increasing production efficiency from 60% to 99% could potentially reduce environmental impacts by 55%68%. The second LCA study (Chapter 3) assessed the environmental and health impacts of producing 1 gram of polyhydroxybutyrate (PHB) via electrochemical and biosynthesis processes, identifying the electrochemical process as the major contributor to these impacts. This study emphasized that the choice of raw materials, the production technologies used, the duration of the experiment, and the efficiency of the output significantly influence the overall environmental and health outcomes.
A social perspective on the adoption of CO2-based single-use bioplastic bottles was offered. The third paper (Chapter 4), through surveys, reveals a strong U.S. consumer interest in sustainable materials, with positive attitudes and a willingness to pay a premium for CO2-based bioplastics. These findings highlight a substantial demand for sustainable product options and provide valuable insights for marketing strategies. The fourth paper (Chapter 5) utilizes Agent-Based Modeling (ABM) to model the factors influencing the adoption of these bioplastic bottles,
emphasizing that lower costs and reduced environmental footprints enhance adoption rates, while higher costs and greater environmental impacts stop it. The study also indicated the importance of social dynamics, showing that strong strength of the social network can significantly promote adoption, especially in closed communities, and highlights the need for strategies that balance economic feasibility and environmental benefits.
Collectively, the LCA reveals that the carbon-negative technologies or products are not truly carbon-negative due to the positive carbon emissions generated during manufacturing processes. Additionally, the consumer surveys and ABM demonstrated a strong demand for sustainable CO2-based bioplastics that are influenced by cost, environmental impact, and social dynamics, underscoring the importance of balanced strategies for promoting adoption. Despite recent advancements in CCUS and carbon-negative products, a thorough analysis of their environmental and human health implications from a social perspective is still needed. This emphasizes the importance of a holistic approach and systems thinking in sustainability
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