Facts about the earth's land resources and population

 a. total land area                                      32 Billion Acres

 b. habitable land area                              16 Billion Acres

 c. potential arable land area                      8 Billion Acres

 d. current land area in production             4 Billion Acres

 e. potential arable land in the U.S.            420 Million Acres

California has about 1.0  X  10^7 acres of land in crop production, about 10 % of the state's land base. Over 30% of those acres of cropland are affected by excess salt in the soil. California produces about 60% of America's agriculture exports.
 

1. Go to URL http://www.census.gov/cgi-bin/ipc/popclockw

The current population of the world is                                             

The population on earth when you were born                                             

The population of the U.S. now                                              

The population of the U.S. when you father was were born                                              

2. World population growth is about 1.7% annually.  How many  additional people will be on the Earth by next year at this time?
         _____________ million
 
3.  How many babies will be born on the earth during a current one hour class period?  Show your answer by dimensional analysis.
 
4.  At the current rate of population growth, by what calendar date would it take humanity to repopulate the entire state of California with 35 million people if we started the process on January 1? Show how you arrive at your answer.

5. What percent of America's 400 million acres of arable farm land is found in California? ________ .

6. According to the author of the text, what are the five functions of soil in an ecosystem?  See text 1.1.
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