Poor, confused vegans. They think that they have the solution to climate change, if they could only convince everyone to adopt their ascetic dietary choices. It is true, factory farming of meat uses lots of fossil fuel inputs. But they miss the boat when they emphasize "of meat" instead of the "factory farming" part. The eggs I collect from my backyard chickens require less fossil fuel input than the factory farmed broccoli that is trucked from California to their local vegan-friendly grocer. Their broccoli requires fossil fuel in the form of fertilizer, tractor passes, getting laborers to and from the field, trucks to haul it to warehouses and distribution centers, and refrigeration equipment to keep it fresh. My chickens, on the other hand, require no fossil fuel inputs; they eat what grows in the garden and provide me with a continuous source of protein and vitamins that are missing from the vegan diet.
As the model of factory farming becomes increasingly untenable, what with Peak Oil raising farming costs, Peak Phosphorus, climate change, weeds becoming herbicide resistant and insect pests becoming insecticide resistant, the crystal ball gazers that come to the conclusion that it is time to ditch factory farming for sustainable permaculture are much more on target than well-meaning vegans. Vegans who want to eat foods that are out-of-season and shipped in from the other hemisphere, or eat grains and soy products that are factory farmed a couple thousand miles away are also part of the problem, albeit to a smaller degree than feedlot carnivores.
Instead of harping on the meat-eating habits of others, people that are concerned about climate change should be preparing to get all of their food locally. Subsistence farmers are the ones that have the lightest carbon footprint, even if they eat poultry they raise themselves, milk from their own goats, and fish from the local pond. Chickens, goats, and fish can turn biomass that is unfit for human consumption into valuable protein and necessary vitamins, like B12. Chickens can eat slugs, and they enjoy them, while slugs can be reservoirs of dangerous protozoan infections if a human were to eat one. Goats can chow down on poison ivy and detoxify a long list of plants that are better avoided by humans.
If it sounds like I am advocating a return to the farming household of yesteryear, with a few animals that are raised for household consumption, that is exactly what I am advocating. The population of Peru is about 30 million, and they raise (and eat) about 85 million guinea pigs a year -- which works out to just shy of 3 cuy consumed per capita. This is sustainable meat, raised on grass and forbs that would otherwise not make it into the human food chain, and no fossil fuels are required to produce it.
The next time a vegan lobbies you to give up meat and gag down an imitation yogurt made from soy juice, politely decline and think about local meats that you could produce.