Spatially explicit life cycle global warming and eutrophication potential of confined dairy production in the Contiguous U.S

Authors: ROMEIKO, X - State University Of New York (SUNY); ZHANG, W - Sun Yat-Sen University; Zhang, Xuesong

Submitted to: Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2024
Publication Date: 10/22/2024
Citation: Romeiko, X.X., Zhang, W., Zhang, X. 2024. Spatially explicit life cycle global warming and eutrophication potential of confined dairy production in the Contiguous U.S. Environments. 11(11). https://doi.org/10.3390/environments11110230.
DOI: https://doi.org/10.3390/environments11110230

Interpretive Summary: The lack of spatially explicit life cycle assessment (LCA) of confined dairy production in the contiguous United States hinders effective measures to reduce greenhouse gas (GHG) emissions and nutrient releases. This study uniquely assesses environmental impacts at a county scale, revealing significant spatial heterogeneity. Optimal counties for sourcing dairy feed and implementing buffer strips to mitigate environmental impacts were identified. By integrating process-based LCA with advanced agricultural models, the study highlights that local feed sourcing alone is insufficient to reduce impacts, emphasizing the need for targeted strategies. Recommendations include prioritizing low-impact feed sources and adopting conservation practices in feed-producing hotspots to enhance environmental sustainability.

Technical Abstract: Assessing the spatially explicit life cycle environmental impacts of livestock production systems is critical for understanding the spatial heterogeneity of environmental releases and devising spatially targeted remediation strategies. This study presents the first spatially explicit assessment on life cycle global warming and eutrophication potentials of confined dairy production at a county scale in the contiguous US. The Environmental Policy Integrated Climate model was used to estimate greenhouse gases (GHGs), NH3 and aqueous nutrient releases of feed production. The Greenhouse gases, Regulated Emissions, and Energy use in Transportation model and Commodity Flow Survey were used to assess GHGs and NH3 from feed transportation. Emission factor based approaches were primarily used to calculate GHGs from enteric fermentation, and GHGs, NH3 and aqueous nutrient releases from manure management. Characterization factors reported by the Intergovernmental Panel on Climate Change and Tool for Reduction and Assessment of Chemicals and other Environmental Impacts model were used to compute global warming and eutrophication potentials, respectively. The analyses revealed that life cycle global warming and eutrophication potentials of confined dairy production presented significant spatial heterogeneity among the US counties. Surprisingly, sourcing feed locally cannot effectively reduce life cycle global warming and eutrophication potentials of confined dairy production. The optimal feed supply scenarios depend on the life cycle environmental impacts of feed production, geographic locations of confined dairy production and specific impact categories. In addition, installing buffer strips in feed producing hotspots can effectively reduce life cycle nutrient releases of confined dairy production.