"Livestock's Long Shadow" says that our diet choices impact climate change more than transportation. I shared that with my Biology class and sensed some disbelief, so I decided to use www.myfootprint.org, a website where you can caluclate your ecological footprint, as a way to convince them that this is true. Your footprint tells you how many worlds it would take to support the human population if everyone in the world lived just like you.
I worked through the footprint questions, choosing all of the default or "average" values as answers. The only answer that I intentially set away from the average, was my diet. First, I chose "top of the food chain - I eat meat, seafood, or dairy at almost every meal" as a description of what I eat. This trial resulted in a footprint of 7.04 worlds. I then repeated the questionnaire, changing only one thing - my diet from "top of the food chain" to "vegan". The footprint dropped to 5.24, a 26% reduction. Impressive!
I then repeated the footprint two times. Both times I let my diet description stay at "omnivore", the default setting, so food choice didn't vary. What I did change was the car I drive. Both times I chose 20,000 miles as the amount that I drive each year, but in one run I chose a "truck or SUV" as my car (this resulted in 7.34 worlds), and the other I swtiched to a hybrid (resulting in 5.99 worlds). The reduction this time was 18%.
Looks like the UN report is right! (Or, more likely, the footprint modelers used the report in writing their computer model.) I know I could have had my students read the report (it's on-line), but this was a much simpler way to get the point across. They had already calculated their footprint, so it was a result they could easily grasp. Most of the students had calculated their footprints to be in the 5-7 range. They were distressed and felt trapped a bit. As teenagers they couldn't easily change the house they live in or the cars their family drives. But they do have control over what they eat. Eating less meat offers an easy way to lower one's environmental impact.
By Ken Kneidel, PhD
Keywords:: ecological footprint effect of meat on environment environmental effect of meat livestock's long shadow impact of animal products