>Just in terms of land-use, livestock is several times less efficient than other kinds of agriculture for the same food output.
This assumes that the land is equally usable for both activities. Many times, it isn't: a lot of land that's good enough for grazing cows doesn't have enough water available for growing plants that people want to (or can) eat. People can't eat grass.
This probably isn't an issue in Denmark, but in many other places it is.
Cows still need water from somewhere in those areas you’re talking about. If the land is particularly poor it also won’t produce enough feed and will have to be supplemented with feed that requires water and energy to grow somewhere else.
Cows are extremely inefficient (2% conversion) at converting calories to meat, so putting cows on that land is also an inefficient use of that land. And land with bad yield for crops also has bad yield for cows and the grass they eat and the water they need. I don't see the proposition being made in these claims.
Cows are so inefficient that we don't need to use marginal land at all to grow food. The majority of arable land is already used for cows yet they produce a disproportionately small amount of food. Weening off cows is a good thing.
You do it then. I like my beef and milk, and I don't care if they use up the land or produce methane.
Dairy cows convert calories to milk at over 24% efficiency. And you still get the meat.
It also ignores that animals produce the manure that is used to fertilize soil to grow crops in.
We use manure because it's coming out of the gills of the animal ag industry, not because it's necessary to enrich crop soil.
Just because plastic bags are ubiquitous doesn't mean it's the only nor best way to carry items around, nor that we'd lose the ability to transport goods if they were phased out, nor that they don't come at a cost despite perceiving them as free.
> We use manure because it's coming out of the gills of the animal ag industry, not because it's necessary to enrich crop soil
Crop soil needs fertilizer somehow
What is your alternative to manure?
Bonus points if it uses less energy to produce than animals, produces less CO2 than animals, takes up less space than animals, or also produces food at the same time
Done any farming lately? You would not get enough yield to feed people without fertilizer. Of course it can be produced from a source different from manure. Nitrogen-based fertilizer is produced from cheap natural gas... oh wait... that is gone,too.