History• It took from beginning of

human history to A.D. 1800 for Earth’s population to reach 1 billion.

• 1800-1930 2 billion

• 1930-1975 4 billion

Current population at 7.1 billion• India is projected to

surpass China in population by 2050.

• U.S will have estimated 420 million people.

Assess Demographic Transition • Birthrates• Total Fertility Rate

(TFR)- average # of children born per women during reproductive lifetime• (15-44)

• A TFR of 2.1 is needed to produce a stabilized population called zero-population growth.

• Rule of 72

Why is this important?

• Virtually all of the major problems we face today relate in some critical way back to population growth.

• Thomas Malthus- Human ability to multiply would exceed our ability to increase food production.

• Will cause famine, disease, war

Lifestyle

• If everyone on Earth lived as a Middle Class American consuming roughly 3.3 times level of food and energy resources and about 250 x clean water 2 billion.

http://www.youtube.com/watch?v=CAUVGYz3pZw

http://www.youtube.com/watch?v=dD-yN2G5BY0

Sources

• Cunnignham, P. William and Cunningham, Mary Ann. Environmental Science a global concern . 12th ed. New York: McGraw-Hill Companies Inc., 2012. Print.

• Damash Mona and etc., The Human Mosaic, 11th ed. New York: Pearson/Longman, 2010. Print.