noaa-forcing-26130 Paleo-pCO2 Database Early Paleocene Multiproxy CO2 Data Kowalczyk, J.B.; Royer, D. Paleo-pCO2 Database Early Paleocene Multiproxy CO2 Data 2019-02-07 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/26130 Investigator J.B. Kowalczyk Investigator D. Royer earth science paleoclimate climate forcing carbon dioxide geoscientificInformation 64000000 cal yr BP 63600000 cal yr BP Complete 39.38 39.38 -104.85 -104.85 1897 1897 Continent North America United States Of America Colorado Castle Rock CO>LATITUDE 39.38>LONGITUDE -104.85 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Jennifer B. Kowalczyk, Dana L. Royer, Ian M. Miller, Clive W. Anderson, David J. Beerling, Peter J. Franks, Michaela Grein, Wilfried Konrad, Anita Roth-Nebelsick, Samuel A. Bowring, Kirk R. Johnson, Jahandar Ramezani 2018 Paleoceanography and Paleoclimatology 33 12 1427-1438 10.1029/2018PA003356 https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018PA003356

Proxy estimates of atmospheric CO2 are necessary to reconstruct Earth's climate history. Confidence in paleo-CO2 estimates can be increased by comparing results from multiple proxies at a single site, but so far this strategy has been implemented only for marine-based techniques. Here we present CO2 estimates for the well-studied early Paleocene Castle Rock site in Colorado using four paleobotanical proxies. Median estimates range from 470 to 813 ppm, demonstrating fair correspondence. The synthesis yields a median of 616 ppm (352-1110 ppm at 95% confidence), considerably higher than previous early Paleocene CO2 estimates (~300 ppm). Ash bed geochronology by the high-precision U-Pb method places the Castle Rock assemblage at 63.844 ± 0.097 Ma (fully propagated 2sigma error). When these results are placed into the broader context of other Cenozoic CO2 estimates from plant-gas-exchange approaches and coeval estimates of global mean surface temperature, a pattern emerges of an Earth system sensitivity around 3C per CO2 doubling during the Paleocene and Eocene, a time with little land ice, then steepening to >7C after the Eocene once land ice was present on Antarctica. STUDY NOTES: Multiproxy paleo-CO2 data from Kowalczyk et al. 2018, contributed to the Paleo-pCO2 Database

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_konrad.xlsx Excel File; Early Paleocene Stomata-Konrad CO2 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_konrad.txt NOAA Template File; Early Paleocene Stomata-Konrad CO2 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018liverwort.txt NOAA Template File; Early Paleocene Liverwort CO2 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_franks.xlsx Excel File; Early Paleocene Stomata-Franks CO2 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_franks.txt NOAA Template File; Early Paleocene Stomata-Franks CO2 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018liverwort.xlsx Excel File; Early Paleocene Liverwort CO2 Data USA/NOAA DIF Version 9.8.4 2019-02-14 2019-02-14