ESS 120 1st Edition Lecture 4 Outline of Last LectureI. The Lost World of KalahariA. Laurens Van Der PostB. Bushman celebrations, dancesII. Sustainable societies have to make difficult decisionsOutline of Current LectureIrrigation and SedimentationI. MesopotamiaA. SodificationB. SalinizationII. PressureA. MigrationB. Agrarian C. SumerCurrent LectureIssue: Irrigated agriculture accounts for 15% cultivated land and 40 % of global food harvest.I. Mesopotamia- “Land between Rivers”, “Cradle of Civilization” A. Sodification- waterlogging, water cant move due to excess sodium. B. Leads to salinization, water-logging, depletion, pollution, reduced yields, soil poisoning** Irrigation and Sedimentation forced people to move North.II. Why did they move north? – PRESSUREA. Forced to migrate due to:1. Environmental damage2. Enable to respond to environmental problems3. Climate change4. Hostile neighbors5. No friendly trade partnersB. Agrarian- There’s enough food for society to settleC. Sumer – collapsed due to:i. “Open-society”, infusion of various cultures ii. Hostile neighborsiii. Environmental damage, inability to respond These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a