Energy usage was what drew my husband to a vegetarian diet about 12 years ago. At the time I did not really pay too much attention to the “why” and mostly just focused on learning new cooking methods. Naturally for our family presentation, he covered this subject. Below is his explanation of why animal products are not an efficient source of food.
Yep, you eat oil. The equivalent of about 500 gallons of oil per year is used to supply food for each American, which accounts for about 19 per cent of the total energy used in the United States, according to the UN. Other estimates are higher, stating that more than a third of all fossil fuels consumed in the United States are used in food production. In either case, that is more energy used for food in the US than for all vehicles combined, and it is exceeded only by the amount of energy used to heat, cool, and power our buildings.
And, guess what, eating meat uses far more fossil fuel than a plant-based diet. Which is why the UN article cited above says that one of the approaches for reducing fossil fuel use in agriculture is to
- Reduce the amount of meat consumed worldwide, since vegetarian options require far less energy to produce than meat.
We put about 10 times as much energy into animals per unit of food than we do for plant crops. About 75% of that energy use is because it takes about 10 calories of feed to make one calorie of meat, depending on the animal being raised. Beef uses the most, and chickens near the least, but the same rule applies: you have to feed livestock far more calories (or pounds) of grain than you get back in calories (or pounds) of meat. And growing all that grain takes a lot of fertilizer, which is produced from fossil fuels. To the fertilizer and other energy needed to grow so much feed, add the energy used in transporting the feed, housing the animals, keeping their buildings (barely) clean and livable, running the slaughterhouses, refrigeration… all of it necessary for meat, but little if any needed for most plant foods.
Of course it’s this same basic fact, that the production of meat requires far more calories as inputs than it creates in outputs, that drives much of the environmental damage it causes. Less meat = less food calories wasted = less land needed to supply human needs = less deforestation. Less meat = less energy wasted = less fossil fuel usage = less greenhouse gases.
You can kind of think of the animal agriculture industry as like having a big leak in the gas tank of your car. It’s horribly inefficient, and you get awful mileage. You can still get around, but you will be stopping at the gas station a lot more often than you should. Way better to fix the leak.
This is one reason why I feel that reducing the animal products in your diet is the simplest and most effective thing you can do to save the planet. By one estimate, changing from a typical American diet to a plant based diet is 50% more effective at reducing your total energy usage than buying a fuel-efficient car. Plus, it may actually save you money, as opposed to the car, which costs thousands of dollars and loses 15% of its value the moment you drive it out of the dealership. So you can start any time – no need for a down payment!