In just the last 15 years 7 agricultural revolutions have taken place. Most of these have occurred in the last 5 five years. Of these 7 agricultural revolutions only 2 increase farm yields. The rest increase acreage available for farming. They do so in unique and interesting ways. The result will be that the earth will be able to support human populations 10-100 times that of current populations. Because its controversial –the genetics revolution is not counted among the 7.