Answer:
If all humans ate only meat, will require more land to grow food crops
Step-by-step explanation:
1) Currently, over 60% of the world food crops are eaten by animals. Given that food crops are generally consumed more than meat in a proportion of 8:1, if all humans ate only meat, the amount of land required to grow food crops will have to be increased by at least 400%
2) Presently, animal agriculture makes use of 70% of lands allocated to agriculture, such that increasing the livestock by an extra 400% will lead to mass deforestation in order to produce livestock feeds
3) It is more costlier to produce livestock than to produce crops, which will make the availability and allocation of land essential for the raising of livestock in order to reduce costs, thereby taking more land.