But if we recall the example of the mobile, we can see how these issues are interconnected. When we have more people, we have more needs. We need more food, more water, more housing, and more jobs. Growing populations also impose greater needs for infrastructure. They strain transportation, education, energy, and waste disposal systems.
More people also require more services, from police protection to health care.
If food is scarce, people go hungry. If housing is scarce, people are homeless. And if jobs are scarce, people are unemployed. They force domestic and international migration, exacerbate social, religious, and ethnic tensions, and drive wars and civil unrest. Virtually every important issue we confront today is caused or multiplied by population growth.