Answer to Question 1
Diminished local, not world, food supply; could be a result of a number of circumstances such as crop failures, political unrest, lack of land, urbanization, population growth, gender inequalitites, access to water, and/or natural disaster.
Answer to Question 2
Field gleaning gathering up leftover crops from farmers' fields after harvest
Food rescue collecting donated perishable foods from a number of sources, e.g., grocery stores, gardens, restaurants, college campus, hotels, caterers, etc.
Non-perishable food collection collecting canned or boxed food from retailers