Growth through natural increase occurs when the birth rate exceeds the death rate. ... The United States has had declining fertility and mortality rates for most of this ... In the second stage of the demographic transition of these regions, ... The population growth rate is still high, about 1.4 percent in 2005.
Eminent Australian scientist Professor Frank Fenner, who helped to wipe out smallpox, predicts humans will probably be extinct within 100 years, because of overpopulation, environmental destruction and climate change
