Really not that big of a deal over that time frame, there are pyramids in south/central america we are just finding with topographic satellite imaging that are only a few thousand years old!

>Wow, that is amazing isn't it? I wonder how they got rid of all the factories and vehicles that caused all that Co2 back then so today there is not evidence of the industrialization back then.
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>
>>>http://www.sciencemag.org/cgi/content/abstract/313/5795/1928
>>>
>>>"...indicates [CO2]atm > 1125 ppm (four times preindustrial concentrations), which confirms that high [CO2]atm coincided with Eocene warmth. "
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>>Are you kidding, that was 50 MILLION years ago!
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>>>
>>>
>>>Neither one of us is going to convince the other. Like you, I believe that reducing our dependence on oil is probably the best thing we can do for our national security.
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>>We can agree on that!