Reply #2: "Never" is a long time. [View All]

[kristopher]

I think there is a lot of speculation that it was higher during both the Permian-Triassic Boundary Extinction Event and the Cretaceous-Tertiary Extiction events. But, it is definately much higher than it has been at any time in the documented record. The ice cores from the Antarctic ice tell us the max in the past 400,000 years is just under 300 ppm. We are now at about 380 ppm.









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