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Re: palaeoclimates = Dana Royer



> <www.personal.psu.edu/staff/d/l/dlr17/>

Thanks a lot! This works.

>From the 2002 PNAS paper:

"Our record shows stable Late Cretaceous-Early Tertiary background pCO2 
levels of 350 -- 500 ppm by volume, but with a marked increase to at least 
2,300 ppm by volume within 10,000 years of the KTB [K-T boundary]. Numerical 
simulations with a global biogeochemical carbon cycle model indicate that CO2 
outgassing during the eruption of the Deccan Trap basalts fails to fully 
account for the inferred pCO2 increase. Instead, we calculate that the 
postboundary pCO2 rise is most consistent with the instantaneous transfer of 
~ 4,600 Gt C from the lithic to the atmospheric reservoir by a large 
extraterrestrial bolide impact. A resultant climatic forcing of + 12 W/m² 
would have been sufficient to warm the Earth's surface by ~ 7.5°C, in the 
absence of counter forcing by sulfate aerosols. This finding reinforces 
previous evidence for major climatic warming after the KTB impact and implies 
that severe and abrupt global warming during the earliest Paleocene was an 
important factor in biotic extinction at the KTB."

Wow. 2300 ppm is... beyond good and evil.