I'm not sure what Wattenberg was researching, but not everybody agrees. This from Wikipedia:


Annual births have levelled at about 134 million per year since their peak at 163 million in the late 1990s and are expected to remain constant. However, deaths are only around 57 million per year, and are expected to increase to 90 million by 2050. Because births outnumber deaths, the world's population is expected to reach 9 billion between 2040 [4][5] and 2050[2].

The rapid increase in human population over the course of the 20th century has raised concerns about whether Earth is experiencing overpopulation. The scientific consensus is that the current population expansion and accompanying increase in usage of resources are linked to threats to the ecosystem,[6] such as rising levels of atmospheric carbon dioxide, global warming, and pollution.