Identify global patterns of calorie intake as one measure of food availability. Distinguish between malnutrition, temporary hunger, chronic hunger and famine. Discuss the concept of food security. Explain how changes in agricultural systems, scientific and technological innovations, the expansion of the area under agriculture and the growth of agribusiness have increased the availability of food in some areas, starting with the Green Revolution and continuing since. Examine the environmental, demographic, political, social and economic factors that have caused areas of food deficiency and food insecurity. Examine the variety of causes responsible for a recent famine.