Here is the information that Dr. Hansen gives Tom.

You might want to keep some notes.  Print this page.    It will help you.

Natural Causes
 
http://www.clearlight.com/~mhieb/WVFossils/ice_ages.html
http://www.geodata.soton.ac.uk/hypermail/envsci/group2/topic4/0001.html 
http://news.bbc.co.uk/1/hi/sci/tech/56456.stm
http://www.sciencedaily.com/releases/2002/07/020731080631.htm

Sun vs Climate graph.
Take a look at this graph.
 


Man made causes
 
http://library.thinkquest.org/26993/global.htm
http://www.dreamchange.org/about/action/warming/fact.html
http://www.umich.edu/%7Egs265/society/greenhouse.htm
http://www.ran.org/info_center/factsheets/04a.html

Carbon Dioxide Readings 

Using the data from the link below, you need to construct a line graph. You will want to use the last numbers represented on the data sheet (this is the average for the year).  DO NOT graph for every year.  Every five years is sufficient.  (For example:  1960, 1965, etc.) 

http://cdiac.esd.ornl.gov/ftp/ndp001/maunaloa.co2
 

 


After researching this topic extensively, you are now in a position to make your own opinions on global warming and the earth.

What do you think is causing the warming trend?


Natural Events 
  Man-Made Events