Q. In science class, we learned that one day there will be too many people to produce enough food and shelter for all of them. I asked my science teacher two questions that he wasn’t sure how to answer. What will happen when the world becomes overpopulated? Will there be limits in the future on how many children people are allowed to have? I would appreciate a response to share with my classmates and teacher.

A. Your questions are ones that people everywhere should be asking. Because of space constraints, my answers will be short, but you can find in-depth coverage of overpopulation issues in publications at a library or bookstore.

Use the Internet to find names of relevant publications as well as to conduct research on the topic. A good starting place for gathering information is www.populationconnection.org/site/PageServer. Founded in 1968 (as Zero Population Growth or ZPG), Population Connection’s mission statement begins with this sentence: “Overpopulation threatens the quality of life for people everywhere.”

The mission statement goes on to say that Population Connection is a “national grassroots population organization that … advocates progressive action to stabilize world population at a level that can be sustained by Earth’s resources.”

Earth already has too many human inhabitants, and the world’s population continues to increase. Many people do not want to acknowledge the problem, but a head-in-the-sand attitude will not change the inevitable consequences of overpopulation.

No animal species can exist without adequate food, water, shelter and other essential resources. Humans are not exempt from this rule.

So what happens when the human population exceeds the resources needed to sustain it? The same thing that happens to any overpopulated species: nature will reduce the population through famine, disease, intraspecies fighting or a combination thereof.

That reality is already playing out for people in some Third World countries. And don’t think it can’t happen here. It can – and will – unless we address the issue of overpopulation.

Because of cultural, political and religious attitudes, almost no world leader is willing to acknowledge the problem, much less take the necessary steps to resolve it.

The Chinese government did impose a limit on the number of children a couple could have. But people used various strategies to get around the restriction, and there were outcries from social rights groups around the globe asserting that couples’ rights were being violated because they were not allowed to decide how many children to have.

Though a thorough study would be necessary to determine the program’s level of success in controlling population expansion, one fact is indisputable: China’s natural resources cannot support a billion people. A one-child policy may not be the best approach for reducing the world’s population, but something needs to be done. Soon.

Will world politicians and religious leaders ever reach accord on appropriate and effective measures to control human population growth? No one can say for certain, but prevailing attitudes are not encouraging.

Many prominent authority figures dismiss the idea that overpopulation is a problem; some even promote programs to increase the population rather than encouraging people to limit the size of their families. You cannot solve a problem if you refuse to recognize that it exists. But you have only to look at the number of starving people in the world to realize that we do indeed have a problem. Not all the agricultural enterprises in the world can produce enough food to feed Earth’s 7 billion human inhabitants.

The underlying cause of almost every environmental problem in the world today is human overpopulation. Air pollution, water shortages, habitat loss, extinctions, invasive species: all are caused or exacerbated by having too many people in the world. We are unique among all animal species in having the ability to solve even a monumental problem like overpopulation. But if we do not solve it ourselves, nature will solve it for us. And we won’t like that solution.