<P> Population size fluctuates at differing rates in differing regions . Nonetheless , population growth is the long - standing trend on all inhabited continents , as well as in most individual states . During the 20th century , the global population saw its greatest increase in known history , rising from about 1.6 billion in 1900 to over 6 billion in 2000 . A number of factors contributed to this increase , including the lessening of the mortality rate in many countries by improved sanitation and medical advances , and a massive increase in agricultural productivity attributed to the Green Revolution . </P>
<P> Population size fluctuates at differing rates in differing regions . Nonetheless , population growth is the long - standing trend on all inhabited continents , as well as in most individual states . During the 20th century , the global population saw its greatest increase in known history , rising from about 1.6 billion in 1900 to over 6 billion in 2000 . A number of factors contributed to this increase , including the lessening of the mortality rate in many countries by improved sanitation and medical advances , and a massive increase in agricultural productivity attributed to the Green Revolution . </P>
what was the world population in the year 1900
what was the world population in the year 1900
1.6 billion
1.6 billion