Overpopulation and concerns about mankind's future

Since I'm stuck with flu I'm devoting more time in reading other people's blogs. One I happened to stumble upon some time ago is about the ethics of genetic modification. A very interesting post about food security caught my attention and brought me to reflect on the concept of food security itself. I thought I might as well share my reflections with you.

The original food security post ended with a question for the readers: what is, according to you, the biggest threat to food security? My personal feeling is that the biggest threat to food security is actually overpopulation. Modern concerns about food shortages tend to ignore the dramatic and uncontrolled increase of human population which has been going on since the industrial revolution. Even if we found a way to provide enough food for everyone, at that point human society would simply increase its reproduction rate because the abundance of resources allowed it to, eventually causing food shortages again and triggering a vicious circle. Moreover, overpopulation poses a serious threat to the future of mankind: while prior to the industrial revolution high mortality rates effectively prevented population overgrowth, now that they've dropped there's 3 possible scenarios our future could evolve into, all of which are strongly unpleasant:

1) Population keeps growing untill it exceeds earth's capacity, at which point not only many people will probably die of starvation but mankind in general might risk extinction because of pollution.

2) Population overgrowth is stopped, but the only way I can see this happening is through birth control policies, which will strongly limit the individuals' freedom to procreate and also involve a strict control from governments over people's private sphere (this has already been tried in China, and strongly criticized by western democracies)

3) High mortality rates are somehow restored, preventing population from growing beyond earth's capacity. Should this scenario occurr, its price will be the death of many in any case. Moreover, the most likely way for it to do so is probably a full scale war for first necessity goods (water in particular) which, due to mass destruction weapons, will undoubtedly cause serious damage to the environment (let alone risking the extinction of mankind itself).

I don't like to be a pessimist, but I really can't figure out a solution to this problem. What do you think?