There is plenty of landmass to produce non meat foods, farm animals actually take up more space due to grazing patterns, how much room is required per animal, having to move them from field to field to provide enough grass etc, on top of that you need to think about the amount of grain being used feed the animals, which is a lot more than we humans need to consume.
For example, soybeans are having to be created genetically modified just to sustain live stock production (currently 50% of GM soybeans go towards livestock, and thats just GM, not organic soybeans) in the EU as there are too many animals and too little food to feed both them as us. That is just the EU as well, figures from america and asia are still being collected.
Look at china, 2 billion people and they self stain their rice crops. This is what I study at university lol.