People leave their homes in the countryside because they want to go to a better school, get a better job and have a nicer life. But most people don’t consider problems about food. When young people move out of the rural areas, they leave their elders to live and farm in the countryside alone, making it hard to provide food for every person in the world. And if more people move into urban areas, cities would have to expand, leaving little space to farm. Inorder to expand, people would have to cut down forests or remove farmland. Trees provide oxygen and reduce the amount of carbon dioxide, so cutting greenery would be terrible. Even if people expand towards the countryside, there would be less land for agriculture.