He already addressed it.
Can The Primal Blueprint Diet Feed the World? | Mark's Daily Apple
Can We Feed the World on the Primal Blueprint Diet? – Part 2 | Mark's Daily Apple
Can the World Go Primal? | Mark's Daily Apple
Also, thinking that the world needs to convert even more of the world's biomass into human beings is a dead end. Someone posted a link to this website yesterday and I found this essay very interesting.
Let me give you an example of some of the lines found on the paper you've received so far--you, I--everyone who grows up in this culture. "Because we have a growing population, we must finds ways to increase food production. Increasing food production is essential and undoubtedly beneficial work." These are the lines on the paper we've been given. But when I turn the paper sideways and write, "Food production is the fuel of our population explosion, and the more we increase it, the more fuel we supply that explosion," everyone goes crazy. I'm not writing inside the lines!
Female, 5'3", 49, Starting weight: 163lbs. Current weight: 135 (more or less).
Starting squat: 45lbs. Highest squat: 167.5 x 2. Current Deadlift: 190 x 3