There are many problems, I agree, and they dominate.

But there are a few advantages such as economies of scale and agglomeration effects.

Hi, Nathalie.

Thanks for your response. This is a question I took an interest in, about two years ago, after having seen it raised in a book about research ethics. I found it puzzling because I'd never stopped to consider it. After having it brought to my attention, I spent a great deal of time trying to think of beneficial reasons to continue to increase our numbers. I couldn't think of a single one that I found sufficient, which made me then ask whether or not we have a moral obligation to decrease our numbers or, at the very least, improve the efficiencies of our existing systems (political, social, economic) so that they more effectively meet the demands of the current global population. There is little doubt, I think, that our current methodology (especially if the US is the example) is an unsustainable enterprise. Here, I'm reminded of one of my favorite quotes related to these ideas: "It is not necessary to change. Survival is not mandatory." - W. Edwards Deming

We are vulnerable and I think we should focus more on sustainable development and aim for human security.

This question is debated in different arenas. In the media, groups favouring population growth, such as business interests, can predominate. And in the recent past at any rate religious interests favouring restrictions on access to effective birth control also make at least a de facto contribution to boosting population growth. (See K. Betts, ‘The Billings method of family planning: an assessment’, Studies in Family Planning, vol. 15, no. 6, 1984, pp. 253-266.)

In academic circles few scholars argue for world population growth, though some may do so at the national level. A good overview of the debate as seen in the mid 1980s can be found in T. King and A. C. Kelley, The New Population Debate: Population Trends and Public Policy, Number 7, The Population Reference Bureau, Washington, D. C., The Population Reference Bureau, 1985.

For a thorough exploration of the case against population growth in the US see R. Beck, The Case Against Immigration, Norton, New York, Norton, 1996 and, in Australia , M. O'Connor and W. J. Lines, Overloading Australia: How governments and media dither and deny on population, Envirobook, Sydney, Envirobook, 2008.

Thanks for the response and references, Katharine.  What would your response be to someone who argues the point "There is no overpopulation problem.  The problem is an uneven distribution of resources - overpopulation is an unfounded belief!"  At least one obvious criticism I see, from the outset, is that we needn't adopt an either/or position (i.e. either there is genuine overpopulation or the problem is uneven distribution of resources).  Both premises (overpopulation and uneven distribution) could be true.  There's much more to consider, I'm just summarizing a potential response, as I see it.

Pat, There certainly is a school of thought that argues that environmental problems (especially greenhouse gas pollution) is caused by over-consumption in the developed world and that over-population in developing countries is a non-issue. See George Monbiot < http://www.monbiot.com/2009/09/29/the-population-myth/>. And yes, there is enough food in the world right now to feed everyone; nonetheless  842,000,000 are hungry, and more people today die of starvation than of AIDS, malaria and tuberculosis combined .

Most environmentalists don't see the environmental problem in such stark terms as does Monbiot, but argue that it's caused both by over-population and by over-consumption by the rich, as well as environmental destruction by the desperately poor. See Jonathon Porrit .

Priorities vary. Paul Erhlich is famous for saying "Whatever your cause, it’s a lost cause without population control".

Just because we could feed everybody adequately now doesn't mean we will. And it also doesn't mean that we would be able to if, even if the will were there, when and if  the population grows from 7 billion to 9 billion.