Overpopulation and underpopulation and the problems they present are the topics of this category.
Regular Blogs
The Environment blog at the New York Times offers numerous posts about the connection between overpopulation and environmental degradation, literacy, hunger, and drought.
http://green.blogs.nytimes.com/
Does what it calls fact-checking about the concepts of overpopulation, climate change, poverty, and abortion and includes inters about the demographic collapse, China and its one-child policy, and how to feed more than seven billion people.
http://www.ruthblog.org/
The focus of this blog is the overpopulation of humans on the earth and the problems which are attendant with that phenomena.
http://thisshrinkingplanet.blogspot.com/