We're not short of food or living space, either. If we replaced all of our farmland with greenhouses, we'd produce ~1000X as much food. If we replaced all o

We're not short of food or living space, either. If we replaced all of our farmland with greenhouses, we'd produce ~1000X as much food. If we replaced all of our farmland with moderately dense city, we'd have enough space for ~100X as many people. Mix and match as needed. Of course we don't need to do either, since the world population has basically stopped growing. We just need to increase food production enough to offset losses of production due to global warming. We can do that by building greenhouses, but there are other, cheaper options, all of which are cheaper than a war.