|Willner, Mark, George Hero, Jerry Weiner. Barron's Global Studies. Hauppauge, NY: Barrons,1995: 738-739.||"The estimated global population of 1.5 billion at the end of the nineteenth century is now approaching 6 billion."||1.5 billion
|"Population." Compton's Encyclopedia. Chicago: Compton's Learning, 1997: 538-539.||[table]||0.8 billion
|"Population." World Almanac and Book of Facts 2001. Mahwah, NJ: Ken Park, 2001: 860-862.||"According to the UN and other estimates the world population reached 6 billion in 1999."||6 billion
|Grun, Bernard. The timetables of History, A Horizontal Linkage of People and Events. New York: Simon and Schuster, 1979: 549, 565.||"Total World population approx. 3.1 billion."||3.1 billion
|"World population growing by about 2 per cent annually estimated at 3.5 billion."||3.5 billion
Currently the estimated value of the earth is approximately 6 billion. From 1750 to present the population has increased by about 5.2 billion. Most of this growth in population has occurred within the last 50 years where it has increased by approximately 3 billion. The large increase in the last century was due to the large increase in cities and metropolises where there were and still are large concentrations of people. Furthermore, especially within the last 50 years most countries economies were and still are for the most part doing well, which meant more time for enjoying what life has to offer and reproduction and as well as a better standard of living.
The world is undergoing a serious situation that Thomas Malthus predicted would happen. During the end of the 1700s, Malthus wrote that food production would be unable to keep up with population growth; therefore increasing poverty and starvation among the people. If the world continues to increase its population at the rate that it is going within another 50 years it might well increase to be over 9 billion and within 50 years from then it might increase to be well over 10 billion.
Anand R. Maharaj -- 2001