I don't know what the arguments would be from a geography degree, but coming at this from an international development perspective, it's definitely a problem. Also, am I the only one getting a failed page from the OP instead of
this link?
I don't see anywhere on the site that adequately addresses the fact that overpopulation is a factor behind some of the major problems in the third world: poverty, war, and environmental exploitation.
I'm going to use Tanzania as an example because that's what I know. Your site pointed out that most of Africa has a low population density compared to the world average, and Tanzania
follows that pattern. But this is deceptive, because Tanzania's population density has
skyrocketed compared to the past. This utterly devastates subsistence farmers, who form the bulk of the population. With millions of young people unable to survive on inherited land, the cities are swamped and
unemployment is rampant.
Let me pull out a relevant statistic from that last article:
Each year, 900,000 young Tanzanians enter a job market that is generating only 50,000 to 60,000 new jobs.
That's the kind of impact overpopulation has, in Tanzania and many other countries. It divides parents' limited education money between children and taxes institutions like schools and hospitals.
Thankfully Tanzania has stayed peaceful, but massive unemployed young populations are also strongly correlated with violence. In
Collapse, Jared Diamond goes into the connection for several Sub-Saharan African countries with high levels of violence, if you don't want to take my word for it. The lack of jobs also leads to increased poaching and other environmental exploitation (consider slash and burn agriculture in Haiti).
That's not to say that everywhere is the same, since obviously some countries are below the replacement rate. I can't find it now, but I recall reading an article saying that the USA and several other countries are actually even lower than they look, because the average is drawn up by certain populations. However, I don't think that overpopulation as a problem should be dismissed as a myth.