I’m a farmer, but before you dismiss this as bias, I don’t have any livestock so do not sell meat.
We own a purely arable based farm and pretty much exclusively grow grain and cereals.
My family had beef cattle on the farm , but they’re sold the heard years before I was born due to lack of profits.
The reason why I say this is due to a few reasons. The soils on our farm are suffering. Especially due to lack of organic content. The soil must be replaced with actual organic matter (like in a garden, it erodes over time and you have to put compost on)
When most farms operated by rotating grazing animals this happens naturally. The grass putting roots down also stops soil erosion, and the dung from the animals too. There are other things that we are just beginning to understand like the important impact of hooves trampling and the delicate micro biome that the cows eating and pooping replenishes.
Just putting dung onto the fields is not enough. Firstly the nutritional balance gets off kilter very quickly (in a way that doesn’t really happen with livestock rotation) and secondly it is difficult to get hold of when you don’t have your own animals.
The alternative to this is fertiliser. Fertilisers are made using fossil fuels. This is far worse for the environment than animals on grassland.
Many farmland is not suitable for cropping. Too hilly/steep, rocky etc. but it is suitable for raising animals, turning otherwise wasted land into human food.
When we have a bad harvest, it often means the crops are not suitable for human consumption. This is then sold for animal feed, turning this into food further down the line as we can then eat the animals. This crop would otherwise have to be destroyed or just left in the field.
But what about greenhouse gases you might be wondering? Animals are PART of the natural cycle. They are not the same as greenhouse gasses released during fossil fuels being burned. Greenhouse gasses are trapped in the soil and plants that they eat, they release and the plants absorb again. plants literally live off carbon dioxide and methane.
How we farm can absolutely negatively affect climate change, but grass fed British beef and lamb is actually important to our ecology and an important food source in order to maximise our environment without destroying it.