Nice discussion folks..
BUT, there is an argument that never makes sense to me "the nature ecosystem could never sustain current amounts of meat consumption", so how can nature sustain amounts of PLANT consumption IF we all change it to plant-based diets?
This does not make sense since for 1 piece of meat we need to eat dozen of different plants; plants as food have a huge impact in nature too.
The animals eat a lot more plants for a pound of meat they gain than humans would need if we only ate the plants. We are in the first day of this year and already over 120 million animals have been killed in the US for food. Approximations on amount of animals killed each year for food in the USA vary, but it is in tens of billions. Can you imagine the strain natural ecosystem would need to sustain to support tens of billions of new animals every year? We are already on the edge when feeding those animals with industrial crops.
Humans are not ruminants. We can not survive on hay. We can survive on the high-nutrition parts of plants, but creating these parts is resource-intensive. In some cases the whole plant is simply difficult to grow (pests, fertilizer, etc.) and in other cases we don't get very much food from each plant.
There is a whole lot of tree attached to a cashew.
Goats and sheep are happy to eat the weeds on a rocky hill, and cattle do almost as well.
Other food animals are happy to eat disgusting waste. Pigs, chickens, and catfish are especially willing.
