As pointed out on this blog, social media is flooded with propaganda posters, many of which contain combinations of errors of fact or logic or both.

This poster, however, is essentially true. I found several academic or government web sites that reported similar values, close to these.

Related to this topic, today I saw something implying we should all eat vegetarian and avoid meat, since we could then grow vegetables on the land where animals are raised for meat production and this would be better for the planet.

The first error is to imply that land used for meat production can be used for other plants. Where I live, in a high desert environment with a tremendous volcanic history, the ground is hard and rocky. Soil layers may only be inches thick before encountering basalt. Grass lands and scrub brush are the predominant plant life. The land, when used for agriculture, cannot be used to grow corn, wheat or vegetables. This is true for perhaps most of the western half of the United States.

The second error is the energy used by transporting vegetables is ignored. Most of north America does not have access to year round agriculture – or even half year long growing seasons. These communities have their food shipped from (often) great distances, which takes energy. Lettuce is probably the least efficient food to be transported in terms of energy per calorie. Lettuce is primarily water, air and some fiber.  There are about 100 calories in an entire head of lettuce.  One pound of 80% hamburger (20% fat) is about 1,200 calories and several pounds fit in the space of one head of lettuce. Similar calculations can be made for other types of food.

Meat can be harvested locally, year round, unlike vegetables.

This does not mean there are no good reasons for choosing to eat differently, only that the assumptions underlying many arguments to persuade others to adopt one’s own eating style, are often incorrect.

As you can see, making arbitrary assessments and value judgements on “good foods for the environment” is not as obvious as many imply.