Also, some may not give birth but opt for adoption.
Adoption does not add to the gene pool of the population in any way.
Do I think the world is overpopulated? No, there is still enough room for another couple of billion.
Some scientists actually believe that the world is overpopulated and that the earth has reached it's carrying capacity a while back.
Yeah, true it does not add to the gene pool. Some can't just handle being a parent and decided not to be one which I think is ok. Imagine what will happen to a child born to a parent who does not want to be one.
About my thoughts on population, that is just my opinion which I think may soon come to pass as we are approaching an era where mortality will be less.
Like I said, I am not berating those that do not want to have kids, I just pointed out the latent consequence of their action/inaction. About approaching the era of less mortality, I would not totally agree with that. Mortality keep increasing every day with the emergence of new diseases and development of resistance by pathogens, wars keep springing up here and there, terrorists and ritualists are killing people like chicken. Do you know the number of people that have been killed by lone gunmen in the US in the past one year or so?
All these are the direct/indirect result of an increase in population and I do not see the trend reversing overnight.
Yeah, I get where you are coming from. The thing is the number of births far outnumber the mortality rate. There have always been deaths from conflicts/wars and diseases even when the world is less than a billion. The trend as you rightly said isn't going to be something that reverses overnight.