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Note: This webpage is for instructional purposes only and was not actually commissioned by Wisconsin government agencies.

Hypothetical task force Report prepared for the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP)

UW-Madison Task Force Members:
   Michel Wattiaux, Department of Dairy Science
   Erin Silva, Department of Plant Pathology
   Alfonso Morales, Urban and Regional Planning
   Kathryn Anderson, Department of Sociology

Scenario | Abstract | Introduction | LCA Methodology | CO2-eq per Kg of Milk  | CO2-eq per Hectare | Climate as a Common Pool Resource | Organic Valley Cooperative | Biodigestion | Conclusions | Citations | Acknowledgements

The Wisconsin state legislators 


Life cycle analysis (LCA) is.

Although there ar.

Eighteen years of data 

Anaerobic digestion . 

Social sustainability is extremely difficult to measure . 



Figure 1: Figure caption here Source: Thoma et al., 2013.

Dairy farming is one . 

Thoma et al. (2013) found that milk production contributed approximately 1.9% of US GHG emission. .  

There are many ways to feed, manage, and care for dairy cattle .

The goal of this research .

LCA — Life Cycle Assessment — Methodology

LCA: A literature review was conducted to identify peer-reviewed articles in which a partial LCA was conducted to estimate and compare GHG emission of milk across production systems.  : 
  • Tier 1: A simplified method that only takes into account livestock population data by animal species/category and an "emission factor" (emission per animal per day), which varied for different regions of the world. 
  • Tier 2: A refined method that takes into account measurements done under specific local conditions, and scientific findings published in peer-reviewed publications.
  • Tier 3: The most sophisticated method that include the use of highly technical simulation models.   
Most of the research cited in this report is from a combination of tier 2 and tier 3 approaches: data collected on farm provided estimates of inputs, outputs and technical performances ("efficiency" of conversion of inputs into outputs) and other farm management practices that help differentiate one production system from another. .

There are three key components of any LCA:
  • The Functional Unit is ;
  • The system boundaries define . 
  • The co-product allocation refers to the process of.        

CO2-eq per Kg of Milk

LCA of Organic vs. Conventional milk: Although there are no studies to compare the carbon footprint of organic and conventional milk in the United States (or Wisconsin), Swedish researchers (Cederberg et al., 2000) conducted an LCA focusing on the impact of feeding and management strategies.

LCA of Grazing vs. Conventional milk: The literature, however, included a number of recent studies comparing grazing systems to conventional systems. Flysjö et al. (2001) analyzed the farm-gate carbon footprint of milk for an outdoor pasture grazing system in New Zealand and an mainly indoor housing system with heavy reliance on concentrate feed in Sweden..

Table 1: Your table caption here
Source: O'Brien et al., 2014.

Sources of Emissions
(kg of CO2eq per 1000 kg of milk)
 United States
 Enteric fermentation   On farm  403.7  373.6
 Manure storage and spreading  On farm  42.1  121.9
 Fertilizer production  Off farm  1.6  0.4
 Concentrate production  Off farm  0.8  1.6
 Electricity and other inputs  Off farm  12.9  15.0
 Nitrous Oxide      
 Fertilizer application  On farm  99.6  16.9
 Manure storage and spreading  On farm  34.5  153.1
 Manure excreted on pasture  On farm  139.9  0.0
 Crop residues  On farm  2.0  3.3
 Fertilizer production   Off farm  30.9  4.7
 Concentrate production  Off farm  7.5  52.2
 Electricity and other inputs  Off farm  6.8  8.7
 Carbon Dioxide      
 Fuel combustion  On farm  13.7  33.3
 Lime application  On farm  1.4  1.2
 Fertilizer application  On farm  6.7  1.6
 Carbon sequestration  On farm  -77.7  0.0
 Fertilizer production  Off farm  43.8  9.4
 Concentrate production  Off farm  21.4  52.7
 Land use change  Off farm  1.8  0.0
 Electricity and other inputs  Off farm  16.0  48.5
 Carbon footprint (On farm)    693  705
 Carbon footprint (Off farm)    144  193
 Carbon footprint (total)    837  898
 Carbon footprint no C. Seq.    914  898

CO2-eq per Hectare

Wisconsin Integrated Cropping Systems Trial (WICST): The life cycle inventory analysis used to assess GHGs from crops in this study is built on 25 years of WICST data collection at the University of Wisconsin, Arlington Agricultural Research Station.  . Specifically:

Social Dimensions: Climate as a Common Pool Resource

Tragedy of the CommonsTo understand the social constraints and opportunities for reducing agricultural greenhouse gas emissions, we begin with the framework of Common Pool Resources (CPR), as specified by Elinor Ostrom’s team in their 1999 Science article. .

Crave Brothers: Crave Brothers Farmstead cheese operates a 750,000 gallon anerobic digester at their 2,000 acres , 750 dairy cow operation in Waterloo, WI. Built in 2007, this digester received $250,000 financial incentive from Focus on Energy for its construction. It is modeled after units in Germany and today produces enough electricity to power 400 homes. The operation sells $300,000 per year worth of electricity back to the local utility company, WE Energy, in addition to the profits it makes from selling waste digester material for animal bedding and organic potting mix.


LCA of Organic and Conventional Milk: The research reviewed by this task force suggested that the carbon footprint of milk produced in Europe and the United States averages approximately 1.0 kg of CO2-eq per kg of milk and was not substantially different whether the milk was produced following the USDA-mandated organic practices or the "conventional" practices. .

Conventional versus Organic Cropping Systems: The integration of pasture and rotational grazing into herd feeding strategies can impact the assessment of overall emissions in both organic versus conventional dairies.  

Social Dimensions: Our study of the social dimensions of organic milk exemplified by the Organic Valley Cooperative led us to conclude that the organic market serve the desires of the segment of the population concerned with a range of issues related to human health and how food is produced and processed.  

Acting only on the physical or biophysical reality will limit our choices and outcomes.


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.

Flysjö, 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.

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.

Thoma, G., J. Popp, D. Nutter, D. Shonnard, R. Ulrich, M. Matlock, et al. 2013. Greenhouse gas emissions from milk production and consumption in the United States: A cradle-to-grave life cycle assessment circa 2008. International Dairy Journal 31, Supplement 1: S3-S14.


This project would not have been successful without the contributions of the outstanding students in our Food Systems, Sustainability, and Climate Change class.  We would particularly like to acknowledge the wonderful and challenging questions, and the specific knowledge that students with different areas of expertise provided.  

About the Authors

To be posted.

Keywords:Case Study   Doc ID:70543
Owner:Sarah S.Group:DS Food Systems, Sustainability and Climate Change
Created:2017-02-08 13:55 CSTUpdated:2017-02-09 15:49 CST
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