| With an increasing interest in renewable energy technologies, including investment, tax incentives and government regulations, it is important to take a broad perspective in assessing potential environmental impacts of any new technology. Informing the decision making process in a broad, systematic way can prevent unintended consequences such as pollution trade-offs. In this dissertation, the case of dairy farm manure management, including energy recovery through anaerobic digestion (AD), is considered. The potential for environmental impacts from the storage and spreading of raw or anaerobically digested manure slurry are evaluated using a modeling approach to quantify the emissions of nitrogen, phosphorus and carbon species. This model was then used in a broad assessment utilizing a life-cycle assessment (LCA) approach. Results of a life cycle assessment study show that implementing AD significantly and substantially reduces fossil fuel depletion. The slight benefit in terms of reducing the emissions of greenhouse gases (GHG), while statistically significant, is not as great, however. Results show important implications for calculating carbon offset benefits, as well as potential pollution trade-offs that can influence decisions about waste management. Endpoint assessments in LCA can be used as a tool in a more inclusive, deliberative approach to decision making at the policy level. Although more development of the methodology is required, preliminary investigation shows that quantifying values of different perspectives can help enrich discourse related to important framing differences. |
