I was a vegetarian for seventeen years. And in the end, it was reflecting on the same questions that led me to stop eating meat that made me start eating it again.
Throughout my years as a vegetarian, I subscribed to the idea that a plant-based diet required less use of water, fossil fuels, and other "resources" than a diet that included meat.
But that's not necessarily true.
Here in New England, the soils are rocky and the growing season is short. A vegetable-based diet requires the importation of protein and fat from distant places, using tremendous amounts of fossil fuels. But the land here is great for grazing sheep and cattle. Eating the flesh of a grass-fed steer who lived out its life on a farm a few miles down the road costs the life of one animal, eating soy trucked across a continent costs the lives of many.
In many parts of the world, agriculture is a large scale operation that destroys habitat. Here in rural New England, small scale animal-based agriculture is an essential part of preserving land that would otherwise be more intensively developed.
The answers to questions about the most sustainable diet is vary widely from place to place depending on soils, climate, population density, and the history of land use.
Some may argue that its not sustainable or realistic for everyone everywhere to eat a diet that relies on sustainably and humanely raised or hunted meat. But I am not necessarily making the argument that it is. Sustainability is not a simple equation. There is not one diet that is appropriate for everyone everywhere. (Though from a health standpoint there are some pretty good indicators of what our bodies did and didn't evolve to eat -- see http://www.toddcaldecott.com/index.php/food/diet/146-diet-a-short-history.)
Every food choice we make has its costs in plant and animal lives.
For a long time only the animal lives matter to me -- for the same reason that for many people only human lives matter, and for others only the lives of humans of the same ethnic background matter -- because we most easily see ourselves mirrored in the lives of beings who closely resemble us and whose sentience is expressed in ways similar to our own.
But when I came to know plants more intimately I came to realize that they too are sentient beings with a desire to live.
Many vegetarian have misinterpreted this as a mockery of their beliefs. (Which oddly echoes the arguments I heard in my years of advocating for animal rights that talking about animal suffering somehow made a mockery of human suffering.) But the emerging field of plant neurobiology is demonstrating that plants have complex neural networks and recognize the difference between self and other. And as an herbalist when I write about talking about the plants, I am not speaking metaphorically --- I have conversations and relationships with Skunk Cabbage and Ghost Pipe as deep and meaningful as my human and animal relationships.
There is no choice of not killing. Our lives depend on the deaths of others. Just as the lives of cattle and bison and salmon and turnips and kale and redwoods do. To truly follow the philosophy of deep ecology and view ourselves as "plain members of the biological community" we need to recognize that we are as much a part of that web of life and death, eating and being eaten as any other species.
There is a sacredness in that. For me I have found that as an omnivore I am more conscious of the ethical and ecological choices I make about food than I was as a vegetarian. When I look back at myself as a vegetarian I see someone who was concerned primarily about what kind of organisms were represented directly on my plate. (And I know this is not true of all vegetarians.) As an omnivore, I am concerned about the web of relationships represented by the food on my plate, and the questions I ask about my impact on that web don't have simple answers.
Eating for me is a sacred act. And I give thanks for all who died to give me life, and honor them as best I can by living a life of working for love, justice, healing, and holy pleasure.