One of the better courses from Coursera. Well designed, well thought out, well presented. He talks about the ample food crop for the planet's population but the diversion of crop to use for animal stock or ethanol as threats to sustainability. The theme of the course is sustainability, and the threats to both food supply and the environment from from current large scale agribusiness farming methods, loss of biodiversity, excessive use of poisons, and excessive reliance of animal products for food.
My only complaint is the ban on posting anonymously, which some need to do to protect the privacy of a neighbor of family member they may have mentioned on a forum in this or any other course.