Wednesday, September 09, 2010
When we think about the environmental impact of our food choices, I think there’s a tendency to focus exclusively on carbon emissions. Sometimes overlooked is the water use associated with food production, a particularly relevant concern to Southern California.
There have been a few different studies that estimate gallons of water used per pound of food. For this graphic, I’ve chosen to use data based solely on agricultural production in California. While the exact numbers are a bit different than what you may find in other places, the general takeaway is the same: meat and other animal products are the least water efficient and raw produce is the most water efficient.
Why? It takes multiple pounds of grain in feed to create a pound of meat, with beef being the least efficient of the bunch. For me this has always been the most compelling arguments for a vegetarian or vegan diet, or at least reducing one’s consumption of meat. If you’re interested in further researching this topic, eXtension has an especially thorough analysis of energy conversion efficiency for cattle.
With our gardens, we seek to maximize water efficiency by planting densely and using drip emitters rather than overhead irrigation. Along with our yield data, we’re also tracking water use in our gardens. I’ll let you know the results once we have enough data!