The carbon footprint of food

Recently, I was in the market for a good layperson's summary of the environmental impact of food choices.  The one I liked best so far was the brief chapter on food late in the book How Bad Are Bananas?: The Carbon Footprint of Everything, by Mike Berners-Lee.

Berners-Lee takes measurement seriously.  At the same time, he is completely frank about how rough some measurements are.  He doesn't waste time figuring out every last significant digit.  Instead, he stays focused on the information that really matters for making sensible lifestyle choices.

Berners-Lee has a talent for explaining technical material.  As just one simple example, he has a delightfully clear explanation of a financial discount rate, an important concept for evaluating payback periods for investments (p. 188).  Other authors might be tempted to skip the topic, but Berners-Lee recognizes that the layreader can understand this issue, without needing any equations.

From the food chapter, here is a summary food tips:

• Eat what you buy. 
• Reduce meat and dairy.
• Go seasonal, avoiding hothouses and air freight.
• Avoid low-yield varieties.
• Avoid excessive packaging.
• Help the store reduce waste.
• Buy misshapen fruit and vegetables.
• Lower-carbon cooking. 

On related issues, I enjoyed seeing a presentation at the Friedman School's Wednesday seminar series last week by Susanne Freidberg from Dartmouth College, who spoke about Life Cycle Analysis (LCA).  Her most recent book is Fresh: A Perishable History.

Among other topics, Freidberg described the use of LCA in corporate sustainability initiatives, of which a leading example is Walmart's.  Although a major retailer won't say "reduce meat and dairy" or "avoid excessive packaging," I nonetheless find the Walmart initiative interesting.  Just for example, this video is blunt: "The raw truth is that the design of this system is unsustainable."  And it provides a nice visual explanation of a food product's life cycle.