Case Study: Carbon Footprint of Organic versus Conventional Milk
The scenario for the case study:
The Wisconsin state legislators have mandate the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) and the Department of Natural Resources (DNR) to assemble a task force of scientific experts to address the concerns of the dairy industry, advocacy groups and other stakeholders across the state. The task force is expected to summarize the most up-to-date scientific literature in relation to greenhouse gases emission from milk production. The question is whether milk produced following USDA-mandated organic practices results in less, the same, or more GHG emission than milk produced by dairy farms using conventional practices. In addition, the report should highlight any other relevant issues that may have implications for the economy of the state, the protection of its natural resources, and the social welfare of its citizens. The task force is expected to provide it's final report by early March 2015 to the Secretary of Agriculture.
The class instructional team is the leadership of the task force. Everyone in the class is a member of the task force and during the month of February, we'll work on reviewing the literature, discussing scientific findings, and interpreting publications in order to produce the report. An executive summary of the report will be made available as a publicly-available web page.
Major Findings (Abstract):
Bell, M. J., E. Wall, G. Russell, G. Simm and A. W. Stott. 2011. The effect of improving cow productivity, fertility, and longevity on the global warming potential of dairy systems. Journal of Dairy Science 94: 3662-3678.
Beukes, P. C., P. Gregorini, A. J. Romera, G. Levy and G. C. Waghorn. 2010. Improving production efficiency as a strategy to mitigate greenhouse gas emissions on pastoral dairy farms in New Zealand. Agriculture, Ecosystems & Environment 136: 358-365.
Cederberg, C. and B. Mattsson. 2000. Life cycle assessment of milk production — a comparison of conventional and organic farming. Journal of Cleaner Production 8: 49-60.
Cederberg, C., U. M. Persson, K. Neovius, S. Molander and R. Clift. 2011. Including Carbon Emissions from Deforestation in the Carbon Footprint of Brazilian Beef. Environmental Science & Technology 45: 1773-1779.
Chadwick, D., S. Sommer, R. Thorman, D. Fangueiro, L. Cardenas, B. Amon, et al. 2011. Manure management: Implications for greenhouse gas emissions. Animal Feed Science and Technology 166–167: 514-531.
Dutreuil, M., M. A. Wattiaux, C. A. Hardie and V. E. Cabrera. 2014. Feeding strategies and manure management for cost-effective mitigation of greenhouse gas emissions from dairy farms in Wisconsin. Journal of Dairy Science 97: 5904-5917.
Global Research Alliance. 2014. Reducing greenhouse gas emissions from livestock: Best practice and emerging options. Accessed March 24, 2015, here
Flysjo, A., M. Henriksson, C. Cederberg, S. Ledgard and J. E. Englund. 2011. The impact of various parameters on the carbon footprint of milk production in New Zealand and Sweden. Agricultural Systems 104: 459-469.
Haas, G., F. Wetterich and U. Kopke. 2001. Comparing intensive, extensified and organic grassland farming in southern Germany by process life cycle assessment. Agriculture, Ecosystems & Environment 83: 43-53.
O’Brien, D., J. L. Capper, P. C. Garnsworthy, C. Grainger and L. Shalloo. 2014. A case study of the carbon footprint of milk from high-performing confinement and grass-based dairy farms. Journal of Dairy Science 97: 1835-1851.
Osterholz, W. R., C. J. Kucharik, J. L. Hedtcke and J. L. Posner. 2014. Seasonal Nitrous Oxide and Methane Fluxes from Grain- and Forage-Based Production Systems in Wisconsin, USA. J. Environ. Qual. 43: 1833-1843.
Ostrom, E., J. Burger, C. B. Field, R. B. Norgaard and D. Policansky. 1999. Revisitng the commons: Local lessons, global challenges. Science 284: 278-282.
Owen, J. J. and W. L. Silver. 2015. Greenhouse gas emissions from dairy manure management: a review of field-based studies. Global Change Biology 21: 550-565.
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