Winter is the time of year when I like to wear boots, watch movies and eat lots of meat. Truth be told, I like meat in the fall, spring and summer too, but a duck cassoulet or a filet mignon just seems that much more satisfying when it’s freezing out, non?
Sometimes, though, with a belly full of beef, I get a nagging feeling. I’ve heard that meat is one of the most energy and land-use intensive foods a person can eat, so perhaps my winter eating habits aren’t ideal – for neither waist nor environment. Should I replace steaks with salads for the greater good of the planet? What is the most ecologically friendly meal, anyway?
As I’ve learned over the last few weeks, there is no prescription for a perfect ecological meal – there are many (many!) unanswered questions about how different foods and farming practices impact the environment. But we could stand to follow three general guidelines: 1. Eat more fruit and vegetables, especially locally grown ones. 2. Yes (sniffle), eat less meat, and fewer processed foods. 3. Overall, think about eating less, period.
The energy we get from everything we eat, whether lettuce or corn, fish or beef, originates from the sun. Plants transform solar energy via photosynthesis; cows eat grass (or corn), the products of this solar energy; we eat cows. But if we left food production entirely to nature, we wouldn’t have enough to sustain ourselves – so we turn to agriculture, which uses various tactics like irrigation, fertilization and pesticides to maximize the amount of solar energy that is captured, harvested and assimilated in our foods.
The problem is that these tactics are very energy intensive – fertilizers are essentially fossil fuels, for example – so while agriculture may maximize yield, it also maximizes energy and water use and leaves behind a trail of chemicals and nutritionally depleted soil. Corn produced using standard agricultural practices uses four times more energy per hectare than corn grown using manpower alone, for instance. Indeed, half of America’s land, 80 percent of its fresh water, and 17 percent of the fossil fuels Americans use go toward producing food.
(Although fish are not part of our standard agricultural system, there are certainly environmental issues surrounding them, too – such as how the fish are harvested and how far they travel to get to you, notes Gail Feenstra, a Food Systems Analyst at the UC Davis Agricultural Sustainability Institute.)
Generally, the higher up on the food chain you go – from plants to animals, say – the bigger the energy trail that is left behind by their production. This is because one has to account for not only what went into raising the animal you are eating, but also what went into producing its food (and cows eat a lot: the U.S. livestock population consumes seven times more grain than Americans do themselves). In addition, as we know from the first two laws of thermodynamics, energy transfer from one form to another is never 100% efficient. As you move up the food chain from green plants to, say, cows, lots of energy is lost along the way: for every kilogram of animal protein in a steak, your delicious cow had to eat about 6 kilograms of grain protein (or about 12 kg of total grain).
Now for a caveat: a little meat isn’t necessarily a bad thing. Ruminant livestock like cows, goats and sheep can be grown on land that’s unsuitable for other crops, and they can also be fed byproducts such as soybean meal, so diets that include some meat may feed more people than vegetarian diets alone, according to a 2007 study published in Renewable Agriculture and Food Systems. This study was considering both grass-fed and corn-fed cows; it’s important to note that even corn-fed cows are typically raised on grass as calves and while no one has directly compared corn to grass-fed cows, many argue that grass-raised beef leaves a smaller ecological footprint.
That said, we certainly don’t need to eat as much meat as we do today. On average, Americans eat more than five ounces of cooked meat and eggs per day, and while no one knows exactly how much meat consumption would optimize our land usage, it’s probably more like two ounces.
We could also do without so many processed foods. Walk down your typical grocery store aisle and most of what you’ll see – with the exception of the aforementioned fruits, veggies and raw meats – has been heavily processed. Whether the food has added sugars or fats, has been morphed into a nugget or has been freeze-dried, processing requires additional resources, which means – you guessed it – it leaves a bigger environmental footprint.
It would also help to eat more locally than we do. “Try to find ways of buying from as close to home as possible,” suggests Joan Gussow, a writer, food producer and professor emeritus of nutrition and education at Columbia University Teacher’s College. That doesn’t mean going to the McDonald’s a mile down the road, though. Shopping at the farmer’s market rather than the supermarket will coax you to eat fewer unprocessed foods, and it may help minimize greenhouse gas emissions since the foods you’re eating haven’t been trucked across the country. It’s especially good if the local food you buy is organic, since organic farming doesn’t use pesticides and leaves the soil in better shape.
Some sources, however, challenge the idea that local and organic is always good. Indeed, a massive UK government-sponsored review of the environmental impacts of food production and consumption found that, when attempting to follow energy costs for the entire product life cycle, organic meat farming was sometimes “worse” for the environment (organic agriculture was definitely better, though).
The report found that under UK conditions organic chicken and beef required more energy than conventional methods. In contrast, organic pig and sheep farming required less than conventional farming. Likewise, the efficiency of mass food transport in the UK means that buying local isn’t necessarily a shortcut to good environmental decisions. The University of Manchester authors suggest that walking to the store, instead of driving, will probably make the most significant dent in your carbon dioxide food bills.
Finally, our planet would be a lot happier if we just ate less. On average, Americans tend to eat 3790 calories every day, according to the Food and Agriculture Organization of the United Nations. We need a lot less than that. A moderately active 30-year-old woman needs about 2,000 calories a day; a similar man needs 2,600. “If you eat more food than you need, then we have to produce more food that you didn’t need,” points out Christian Peters, a postdoctoral associate in crop and soil sciences at Cornell University. “It doesn’t make sense for the environment. It doesn’t make sense for your health, either.”
Alas, what does this mean for yours truly, the Biggest Beef-o-Phile in Brooklyn? Sadly, I’ll admit, I could do with less meat and more fruits and veggies on my plate. At least I can pat myself on the back for not eating THAT many processed foods – I haven’t had a McNugget in 15 years, and I don’t eat cereal for breakfast. But then, wait: beer is a processed food, isn’t it?
Less meat AND less beer? This is going to be a tougher winter than I thought.
WHY GRAINS ARE GREENER THAN GRISTLE
ENERGY: Eleven times more energy is required to make a calorie of beef protein than a calorie of grain protein.
WATER: When compared pound for pound, animal production requires at least 100 times more water than grain.
LAND USE: Beef requires 31 times more land area than the equivalent quantity of grain.
HOW MUCH ENERGY (IN CALORIES) IS REQUIRED TO MAKE A SINGLE CALORIE OF MEAT?
(from the September 2003 issue of the American Journal of Clinical Nutrition)
Lamb: 57 calories (~ 29 if pasture fed only)
Beef: 40 calories (~20 if pasture fed only)
Pigs: 14 calories
Turkeys: 10 calories
Broiler chickens: 4 calories
HOW MUCH ENERGY (IN MEGAJOULES) IS REQUIRED TO MAKE A SINGLE KILOGRAM OF MEAT?
(from the UK Department of Environmental, Food and Rural Affairs 2006 “Shopping Trolley” report)
Beef: 28 MJ
Lamb: 23 MJ (organic lamb: 18 MJ)
Pork: 17 MJ
Chicken: 12 MJ (organic chicken: 16 MJ)