Q: If everyone went vegan, how would that affect the environment?

A: Much more land is required to produce animal foods such as meat & milk than to produce the equivalent amount of plant foods (to give the same amount of energy or the same amount of protein). So, when everyone goes vegan, the same population can be fed on less farm land, and there will be no more need to destroy areas of natural environment to make new farm land. Indeed, the farm land that is already under cultivation could support a much larger human population, and some of it could be returned to nature, and recreational use. Plant foods also require less water and energy to produce, providing further benefits.