It is still unclear if the land that is used for grazing could be suitable for growing crop that could be used for human consumption. Where do you think the grazing land comes from? Clearing natural habitat. And no, except for extreme conditions (like people living in extreme cold), meat is not a necessary food. An average human living in a city/village with moderate temperatures (especially when most of their time is spent inside buildings) does not need meat, they only want it.
We don't need those grazing lands for growing food (some nuts forests would be cool, though). We should afforest/rewild it to store maximum carbon in those lands, repair water cycle, enable biodiversity to return (70% of species is lost in the last 50 years or so), and use land for animal feed crops to feed humans instead.
If we'd switch to plant based diets, we'd free an area the size of Africa to return back to nature, storing enough carbon to return to 280ppm, stop biodiversity loss, while feeding comfortably 10+ billion people.
Feeding 10 billion people by 2050 within planetary limits may be achievable
A global shift towards healthy and more plant-based diets, halving food loss and waste, and improving farming practices and technologies are required to feed 10 billion people sustainably by 2050, a new study finds.
Ooh boy the numbers are bigger than I remember. I don't think the world will shift to a completely plant-based diet for the foreseeable future but we really do need to atleast move toward that reality.
