Paleo-pCO2 Database Early Paleocene Multiproxy CO2 Data Kowalczyk, J.B.; Royer, D. Kowalczyk, J.B. Royer, D. earth science/paleoclimate/climate forcing (Castle Rock CO>LATITUDE 39.38>LONGITUDE -104.85) 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 NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Kowalczyk, J.B. Investigator : Royer, D. 2019-02-07 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/26130 https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_konrad.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_konrad.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018liverwort.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_franks.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_franks.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018liverwort.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_konrad.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_konrad.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018liverwort.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_franks.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_franks.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018liverwort.xlsx English https://www.ncdc.noaa.gov/paleo/study/26130 https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_konrad.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_konrad.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018liverwort.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_franks.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018stomata_franks.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/kowalczyk2018liverwort.xlsx 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 Ramezani2018Multiple Proxy Estimates of Atmospheric CO2 From an Early Paleocene RainforestPaleoceanography and Paleoclimatology33121427-143810.1029/2018PA003356https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018PA003356 START YEAR: 64000000 cal yr BP * END YEAR: 63600000 cal yr BP -104.85 39.38 -104.85 39.38