If you’ve heard that beef has a higher carbon or land footprint than many other foods, you should know that is largely correct. Higher footprints for beef are driven by the biology of cattle — they are large ruminant animals that take longer to reach maturity and harvest than other livestock species. For example, a chicken is typically harvested at six weeks of age while a grain-finished steer likely will be 14 to 18 months old.
That said, with respect to differences in environmental footprints between individual foods, radical changes in diets do not necessarily translate into positive environmental outcomes. And extreme dietary changes may come with unintended negative consequences. This was illustrated in a study recently published in the Proceedings of the National Academies of Sciences. The researchers put the "less meat, less heat" hypothesis to the most extreme test — what if every American, including our pets, went vegan and we eliminated animals from our agricultural systems?
Greenhouse gas (GHG) emissions in the United States indeed would decrease, by only 2.6 percent, and we would produce more total pounds of food and calories. Importantly, that 2.6 percent reduction in GHG emissions is not attainable by solely eliminating livestock agriculture — all livestock in the United States would have to disappear. If we keep the animals around, the emissions associated with them would continue, and if we were to replace cattle with another large ruminant on our grassland ecosystems, such as American Bison, the emissions reduction would be less than 2.6 percent. While emissions would decrease, without animals our food supply would be lacking in key micronutrients such as vitamin B12, which is only found in animal source foods, and we’d rely more on synthetic fertilizers for crop production as we’d have no animal manure.
To read the rest of the story, please go to: GreenBiz
