Old Rocks
Diamond Member
CO2 as a primary driver of Phanerozoic climate
Dana L. Royer, Department of Geosciences and Institutes of the Environment, Pennsylvania State University, University Park, Pennsylvania 16802, USA,
[email protected] Robert A. Berner, Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520, USA
Isabel P. Montañez, Department of Geology, University of California, Davis, California 95616, USA
Neil J. Tabor, Department of Geological Sciences, Southern Methodist University, Dallas, Texas 75275, USA
David J. Beerling, Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, U
ABSTRACT
Recent studies have purported to show a closer correspondence between reconstructed Phanerozoic records of cosmic ray flux and temperature than between CO2 and temperature. The role of the greenhouse gas CO2 in controlling global temperatures has therefore been questioned. Here we review the geologic records of CO2 and glaciations and find that CO2 was low (<500 ppm) during periods of long-lived and widespread continental glaciations and high (>1000 ppm) during other, warmer periods. The CO2 record is likely robust because independent proxy records are highly correlated with CO2 predictions from geochemical models. The Phanerozoic sea surface temperature record as inferred from shallow marine carbonate δ18O values has been used to quantitatively test the importance of potential climate forcings, but it fails several first-order tests relative to more well-established paleoclimatic indicators: both the early Paleozoic and Mesozoic are calculated to have been too cold for too long. We explore the possible influence of seawater pH on the δ18O record and find that a pH-corrected record matches the glacial record much better. Periodic fluctuations in the cosmic ray flux may be of some climatic significance, but are likely of secondorder importance on a multimillionyear timescale.
http://www.atmosedu.com/Geol390/articles/RoyeretalCO2GSAToday'04PhanerozoicClimate.pdf
Three
This is a full article, with many graphs which totally disagree with your graph concerning the depth of the CO2 excursion in the Ordivician. If you like, I can find many more articles like these, published in peer reviewed scientific journals.
Dana L. Royer, Department of Geosciences and Institutes of the Environment, Pennsylvania State University, University Park, Pennsylvania 16802, USA,
[email protected] Robert A. Berner, Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520, USA
Isabel P. Montañez, Department of Geology, University of California, Davis, California 95616, USA
Neil J. Tabor, Department of Geological Sciences, Southern Methodist University, Dallas, Texas 75275, USA
David J. Beerling, Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, U
ABSTRACT
Recent studies have purported to show a closer correspondence between reconstructed Phanerozoic records of cosmic ray flux and temperature than between CO2 and temperature. The role of the greenhouse gas CO2 in controlling global temperatures has therefore been questioned. Here we review the geologic records of CO2 and glaciations and find that CO2 was low (<500 ppm) during periods of long-lived and widespread continental glaciations and high (>1000 ppm) during other, warmer periods. The CO2 record is likely robust because independent proxy records are highly correlated with CO2 predictions from geochemical models. The Phanerozoic sea surface temperature record as inferred from shallow marine carbonate δ18O values has been used to quantitatively test the importance of potential climate forcings, but it fails several first-order tests relative to more well-established paleoclimatic indicators: both the early Paleozoic and Mesozoic are calculated to have been too cold for too long. We explore the possible influence of seawater pH on the δ18O record and find that a pH-corrected record matches the glacial record much better. Periodic fluctuations in the cosmic ray flux may be of some climatic significance, but are likely of secondorder importance on a multimillionyear timescale.
http://www.atmosedu.com/Geol390/articles/RoyeretalCO2GSAToday'04PhanerozoicClimate.pdf
Three
This is a full article, with many graphs which totally disagree with your graph concerning the depth of the CO2 excursion in the Ordivician. If you like, I can find many more articles like these, published in peer reviewed scientific journals.
