It depends on the kind of lifestyle those people enjoy, says Lisa Naughton, a UW-Madison professor of geography and environmental studies.
The late 18th century English economist Thomas Malthus – one of the first to express concern about overpopulation – observed that there should be no more people in a country than can “daily enjoy a [...]

World population has reached 6 billion. What does this mean for the environment, resources, humanity? Six billion people on Earth — is that a good thing?