"An area the size of Russia and Canada combined could be freed from use as pasture or cropland used to grow animal feed, if people switched from current levels of meat consumption common in Europe and the United States to a diet based on plant-based protein."
OK, then why are you drawing the line arbitrarily between cattle and tomatoes, when both are less efficient than potatoes? I posed that as question, but I don't think there's an answer, because, indeed, I think precisely the problem is that you're making an arbitrary distinction.
My entire point is that, sure, it's less efficient, but that doesn't mean there's not reasons for raising cattle.
The world as it is now is tight for resources. We are tight for land, oil, energy, and water. Globally we are trying to use less of all 4 to move towards a sustainable future. Farming uses up quite a large part of all 4 of those (meat farming creates some nasty byproducts along the way as well like water polution, air polution, steroids in our food, etc). We need to make some cut backs right now. Because meat is 10 (sometimes 50) times less effeceint, it's a good candidate for cutbacks. Maybe we can bring it back when we learn how to manage our resources better, but for now, I think it needs to be scaled way back.
You can bet your ass that if producing some vegetable like rice used as many resources as beef did, it would be gone in a heartbeat!
I suppose in the very distant future there could be a day where we have to choose between potatoes and tomatoes... I hope that day never comes.
