by JJ Cousins, JP Newell
Climate change has had a significant impact on water resources, threatening its access, quality, and availability. Faced with severe drought periods and a decrease in snowpack levels, cities are under pressure to reduce greenhouse gas emissions while securing a stable water supply. In establishing these programs, there is a growing need to evaluate the connection between water and energy consumption and to measure the carbon footprint of water systems. This paper combines an urban political and industrial ecology approach to investigate urban water metabolism in Los Angeles, California. The authors employed a life-cycle assessment, while integrating spatial differentiation into the modeling process for comparison with the standard eGRID approach, to represent the energy and emissions intensity of water supply sources, and to determine the urban political ecology. Emissions factors for the utility emissions and energy sources were developed to specify functionality for the sourcing and conveying, treatment, and distribution of water to consumers. These factors also facilitated calculations of the energy and emissions burden. Interviews conducted with water managers were supplemented with an analysis of policy documents, newspaper articles, and agency reports to determine how urban metabolism is affected by governmental agencies and societal groups. By coupling life-cycle assessment and spatial analysis with political ecology, the authors were able to vet the socio-political dimensions of greenhouse gas emissions. The results of the spatially explicit approach yielded a 38% lower emissions footprint than the eGRID approach, meaning electricity emissions can vary depending on the eGRID subregion, spatial scale adopted, and administrative data. By recognizing the metabolic inputs and outputs of products and processes while identifying how they are shaped by politics, history, and social power, the political-industrial ecology method described in this paper can promote greater understanding of urban resource ﬂows and metabolisms for a more sustainable and resilient future.