We investigate the impact of differently sourced diets to

  • Help regional and community planners, food systems advocates, and consumers can build and support food supply chains with the most efficient energy use and lowest environmental impact.
  • Give growers, processors, and distributors in relevant regions better tools to improve energy use efficiency in their operations where it matters most.

Research includes:

  • Purchasing Michigan grown, processed, and sold tomatoes
  • Purchasing California grown tomatoes processed and soled in Michigan
  • California vs. Southeastern paddy rice growing practices


Some Essential findings


  • Shipping California-produced products to Michigan consumers does not substantially increase the climate footprint compared to Michigan products, because
    • CA production is highly efficient per unit of yield
    • lime soil amendment needed for acid soils in MI releases CO2
    • rail transport from CA to MI is very fuel-efficient.
  • Switching from rail to truck transport between CA and MI would result in almost 50% higher life cycle energy use and 25% higher GHG emissions for CA-produced products, giving them 20% to 50% larger footprints than MI products.
  • Greater energy inputs and concentration of product make the production and processing stages a larger relative share of the total footprint in paste than in diced tomatoes.
  • Highly concentrated products (e.g. paste) create a larger total footprint per kg than less concentrated products, but also amplify existing energy and GHG efficiencies in field production of the raw product. Therefore, CA diced tomatoes have a slightly larger total climate footprint than MI diced, but CA paste has a smaller footprint than MI paste.



  • Our gross, national-scale data suggest that significant differences may exist in energy and greenhouse gas efficiency of rice grown in different regions of the country (although different regions also produce different types of rice - from long grain to medium/short grain).
  • The significance of methane emissions in rice production merits closer examination using more detailed calculation protocols that can account for local climate and cropping practices.
  • Producing a second crop in the growing season may substantially increase methane emissions, thereby increasing total life cycle greenhouse gas emissions per kg of rice produced.


Read the Report: Life Cycle-Based Comparisons of Energy Use, Greenhouse Gas Emissions and Water Use of California versus Michigan Processed Tomato Products and California versus Southeastern Paddy Rice

*This is a technical report, and has not been peer reviewed.

Additional materials

Project Partners: