If you look at the curve of world population and compare it to fossil fuel production, the two are parallel. This is because, through our ingenuity, we have been able to turn fossil fuels into life-support for humans. Shelter, heat, fertilizer, and shipment of food across the world over the past century-and-a-half have been overwhelmingly dependent on fossil fuels, especially oil. With oil supplies suspected to “drop off a cliff” to half of our current production in only twenty years, how can industrial agriculture maintain a population of over six billion people? Renewables? More planets? Are you fuckin’ crazy? The food will have to be grown more locally, using human labor.
For each calorie of food consumed, it has required about ten calories of fossil energy to plant, fertilize, harvest, ship, package, and refrigerate it by the time it reaches your plate. This is why people like Richard Heinberg and Sharon Astyk are sending out a “call to farms”. They suspect somewhere in the order of fifty to one-hundred million new food producers will be needed in the United States to make up for lack of oil to run machinery and deliver products over vast distances.