Actually, no, it’s not new. The macro farms began to be installed in the decade of the sixties. We have been consuming animal products that come from macro-farms for many years. But for you to understand what has happened recently and why they are being talked about now, I have to explain to you, first, what they are.
These are very intensive production systems. That means there is a high density of animals on each of these farms, from thousands of pigs and cows to tens of thousands of poultry. In addition, they are highly genetically selected animals so they give a very high production. This entails some environmental problems such as soil contamination by feces and air pollution by the emission of CO₂, ammonia, and, in the case of cows, also methane.
Ammonia comes from animal feces and urine; the CO₂ from their breath and the methane is expelled by ruminants through their mouths, not by farts, as is often said, due to the fermentation of food in their rumen, which is one of the parts of the digestive system of ruminants.
The problem is that these gases are polluting and negatively affect climate change. And at the same time, the enormous amount of feces produced by macro farms is detrimental to the soil because there are not enough plants that take advantage of it as nutrients.
And why have macro-farms now become a problem when they seemed fine to us before? The reason is that these intensive systems were used in very few countries, only in industrialized ones. In the rest of the countries, a much more vegetarian diet continued to be eaten because meat and animal products were a luxury. But when large countries like China, India, South Africa, or Brazil have begun to consume more products of animal origin produced in the same way, it has become an unsustainable system for the environment.