As for legitimate new ideas, not just some dreamy speculation that technology will save us? I can’t say this is new, it was also on the table in the 70’s with the synthetic fertilizer, but if humans became largely vegetarian, or even just stopped eating/milking cows, we would have much more land available to produce grain to feed people directly. Feeding folks directly is more efficient than trafficking all that grain through another species before we get at those calories. Cows are the least efficient, at least when they eat corn raised on factory farms. If they’re just wandering around grazing on otherwise unfarmable land, their caloric efficiency increases. In a nutshell, then, the new humane act is to collectively stop eating animals, not for the animals, but for your global neighbors.

“World population is projected to grow from 6.5 billion in 2005 to nearly 9.2 billion by 2050. To feed a population of more than 9 billion free from hunger, global food production must nearly double by 2050. The entire population growth will take place in developing countries and it will occur wholly in urban areas, which will swell by 3.2 billion people as rural populations contract. That means that a shrinking rural work force will have to be much more productive and deliver more output from fewer resources. Higher productivity requires more investment in agriculture, more machinery, more implements, tractors, water pumps, combine harvesters, etc., as well as more skilled and better-trained farmers and better functioning supply chains.”

pdf of full FAO Food Outlook here