while the three worlds of individual fossil fueldriven growth of citizendriven sustainable growth and of fast globallydriven growth all present common risks such as those related to the environment their magnitude varies substantially between scenarios the performance of each of these scenarios is compared in order to facilitate the identification of strategies to manage risks and avail of future opportunities which will be discussed in chapter generally food and nutrition security is defined around four pillars or dimensions including the availability stability access and utilisation by the body food security exists when all people at all times have physical social and economic access to sufficient safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life fao