how would food production and water supply be protected in areas that are affected by el nino and la Nina?
During el Nino, warm water in the pacific ocean is carried eastward, towards California, as opposed to westward (where it would normally be traveling) to areas like Indonesia and Australia. This leaves the water near Indonesia and Australia much colder and less nutrient rich, meaning that fish won’t want to live in those areas. This hurts local fisheries and the food supply for coastline cities. El Nino also leads to drought conditions in Indonesia/Australia and increased rainfall along the west coast of the US.
La Nina does the opposite. It carries more warm water and monsoons to Indonesia/Australia, and leaves California much drier.