This is not about the guilt-ridden question: Should I eat meat? That personal dilemma has already been debated thoroughly on Grist and elsewhere. Instead, here’s another dose of angst for us meat eaters, just in case we needed one:  If we’re going to condone the killing of animals, the least we can do is eat all of the resulting meat.

You’re welcome.

When I do readings for my book, American Wasteland, I begin by talking about the ethical shortcomings of wasting food. Primarily, there’s the idea that someone would have loved to eat the foods that we squander. Wasting food devalues the suffering of millions in America and a billion worldwide who don’t get enough to eat. These days, 15 percent of Americans [PDF] are food insecure, or struggle to find enough to eat. And food banks and hungry people have a hard time getting sufficient protein, especially the kind not found inside a tin can or a cylinder of casing.

Wasting meat raises the stakes to create an ethical double whammy. Squandering animal protein — and some would include offal here — debases our quotidian killing of animals. As Paul Root Wolpe, director of the Emory Center for Ethics, told me: “To treat food cavalierly leads to a lack of appreciation of the importance of food, of the fact that some go without it, of the suffering of animals that the carnivores among us are willing to tolerate to eat our food.”

Ideally, the growing number of hungry people would motivate us to treasure our edibles — meat especially — at all stages of the food chain. But, contrary to what we claim, we do not. Globally, at least one-third of all food isn’t consumed [PDF]. Domestically, that figure jumps to about 40 percent. And zooming in further, we squander about 25 percent of the food we bring into our homes.* It seems that in the cold calculus of everyday life, ethics aren’t all that motivating.

What about the financial incentive to trim our waste?  Like the ethical one, the economic case against wasting animal protein is simple — it’s money down the drain (or in the trash). Yet, that argument must not be a very compelling one, as we still waste plenty of meat. Roughly 20 percent of all meat produced in the U.S. isn’t consumed. Supermarkets squander 9 percent [PDF] of their meat, poultry, and seafood. And a U.K. study found that [PDF] about half of all uneaten meat waste is avoidable.

Conventional meat is artificially cheap due to grain subsidies, so we treat it accordingly. Paying the true cost of proteins would prompt us to use all — OK, more — of what we buy.** It’s the same as the “gas should cost more” argument. Anecdotal evidence shows that we’re more conscientious about using up costlier items. Think about how you’d approach that $20 farmers market chicken (perhaps a heritage breed bird fed a diet of sheep’s milk, soy, and hazelnuts) compared to the frozen, $5 supermarket bird.

Meanwhile, the percentage of our income we spend on food at home has steadily declined since World War II, reaching an unprecedented low of 6 percent. No other nation spends less on food. Accordingly, our rate of squandering has ballooned — increasing by 50 percent from 1974 to 2005. That dollars and cents, common sense incentive not to waste is waning in the age of busy lives and fast, cheap food.

Given the failure of ethics or economics to stem our meat squandering, what’s a professional food waste lamenter to do? Lean on the environmental argument. And, fortunately, it’s a clear-cut case. You’ve probably heard that the meat industry has a hefty carbon footprint. Well, it’s no joke, with lamb, beef, pork and, surprisingly, cheese production all creating more than five times the greenhouse gas emissions of dry beans or tofu. Livestock farming is a real resource hog, as energy input far outweighs energy output [PDF]. Creating one calorie of pork requires 14 kilocalories of fossil energy. Lamb has a 57 to 1 ratio, while beef and egg production are right behind that at 40 to 1 and 39 to 1, respectively.

Raising ruminant animals like cows, sheep, and buffalo is one of the leading sources of methane, a greenhouse gas about 25 times more virulent than CO2. And sending animal products to the landfill only creates further methane emissions when that meat decomposes there. Plus, we can’t ignore how growing grains to feed livestock impacts our environment. The pesticide and fertilizer runoff stemming from the all-too-common monoculture farming harms our waterways, before pooling in the Gulf of Mexico. And let’s not forget the damage done by concentrated animal feeding operations. Raising animals in such density converts their waste from a solution to a problem.

On its own, the environmental impact from producing animal protein is bad enough. But squandering as much meat as we do — again, about 20 percent — renders the pollution and energy expended toward its creation also wasted. It’s not only indefensible, but unethical.

There will always be some edible food not eaten. There just will be. But, there’s no reason we can’t dramatically trim the amount of wasted animal protein. Eating less meat or abstaining altogether is one option. Yet, for omnivores, efficiency is the answer. It’s the least we can do.

* The 25 percent home waste figure comes from Bill Rathje, founding director of the University of Arizona Garbage Project. He said that they found hard, smelly evidence in household trash that 15 percent of grocery purchases aren’t eaten. Then he estimated an additional 10 percent is sent down garbage disposals.

** Hopefully, beefed up assistance for the hungry would accompany any widespread increase in meat prices.