More Video Clips of Scientists Visiting Ms. Chang's Class at WHS
Dr. Dan Schrag, Harvard University:
and why what's happening today is different that what's been happening as Earth rocked in and out of ice ages during the past two million years:
Dr. Paul Hoffman, Harvard University
Dr. Hoffman, in a visit to WHS, explains in two minutes what carbon dioxide is, what is does, and the greenhouse effect.
Back to the Eocene? Earth's last "hot house." Note: Update: CO2 levels were more likely between 1000-1500 ppm during the Eocene, than "above 500" ppm)
Dr. Schrag, On Where is Earth Headed....
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