The debate about whether population growth is an issue that demands our attention depends upon what problem you are concentrating on.
The only thing is that in Africa they're already stressed for resources, which will only get worse as the world warms, and it's there that the birth rates are so high.
So if your issue is human suffering, population growth is a big component.
Audio: Is the population bomb ever going to explode?
UN World Population Graph
And guess what... doing the right thing has real rewards.
Global population growth: Hans Rosling on TED.com