Is the population declining?

I just watched an interview on the Daily Show which espoused a theory I have heard a lot recently that the population will stabilize in 2040. They say people are having far less children everywhere in the world and this is going to peak in roughly 2040.

I suppose we will find out soon enough, but I am skeptical of this theory. It doesn't seem to take into account certain artificial motivators of population growth. In the show, they do mention the Catholic church, but more than that, I was thinking about business.

Business growth is dependent upon stock going up and the only way you can consistently do that on any measurable scale (i.e. the GDP) is by having a larger and larger consumer base to exploit.

Interesting.