Spatially Resolved Greenhouse Gas Emissions from U.S. Dairy Products

As the world's second-largest milk producer, the U.S. dairy industry aims to achieve net GHG neutrality for all dairy products by 2050. Meeting this target requires understanding emissions across the dairy supply chain, extending beyond farms to include full processing activities. While previous Life Cycle Assessments (LCAs) evaluated individual products like fluid milk and cheese, no comprehensive cradle-to-processing gate LCA exists for the industry. Moreover, prior LCAs often allocated facility-level emissions across multiple products, overlooking variations in energy and materials among coproducts. This study addresses these gaps, quantifying total cradle-to-processing gate emissions, emissions per kilogram of product, and product emissions per kilogram of fat and protein-corrected milk (FPCM) across 12 regions covering 99.96% of U.S. dairy production. In 2020, total emissions were 163.3 million tonnes CO₂e, with raw milk production accounting for an average of 81%. Postfarm gate emissions varied regionally due to differences in product mix, energy use, electricity grid composition, and transportation distances. Results identify raw milk production as the largest emissions source across the evaluated uncertainty range, indicating that mitigation will require coordinated action across both farm and processing stages. Findings provide critical insights for policymakers and stakeholders to effectively prioritize strategies such as energy efficiency improvements and renewable energy adoption in future sustainability initiatives.