we should be more technical about how we use the term. because its not so simple.. its not just about the overpopulation of the entire world. the problem is over population in select areas.  its not sustainable to have such concentrations of people in certain areas. or to overwhelm and overburden certain areas that arent ready for an influx of a higher concentration of people. populations need to be spread out and grown gradually, and the people need to be on the same page in regards to sustainability.  cant just import a ton of people en masse to an area not ready for it. its how fertile and healthy areas become ruined.
United States