Paleo-pCO2 Database ODP999 4.6 Million Year Boron Isotope and CO2 Data Bartoli, G.; Hönisch, B.; Zeebe, R.E. Bartoli, G. Hönisch, B. Zeebe, R.E. earth science/paleoclimate/climate reconstructions|paleoceanography (pH,delta 11B,null,dimensionless,null,climate reconstructions|paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 11B,Trilobatus sacculifer,null,per mil,null,paleoceanography,null,thermal ionization mass spectrometry,N,N-TIMS) earth science/paleoclimate/climate forcing|climate reconstructions|paleoceanography (age,null,null,million years ago,null,climate forcing|climate reconstructions|paleoceanography,null,null,N,null) earth science/paleoclimate/climate forcing|climate reconstructions|paleoceanography (age,null,two standard deviations,null,null,climate forcing|climate reconstructions|paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 11B,Trilobatus sacculifer,two standard deviations,per mil,null,paleoceanography,null,thermal ionization mass spectrometry,N,N-TIMS) earth science/paleoclimate/climate forcing|paleoceanography (carbon dioxide,bulk atmosphere,null,parts per million,null,climate forcing|paleoceanography,null,null,N,based on planktic foram delta 11B) earth science/paleoclimate/climate forcing|paleoceanography (carbon dioxide,bulk atmosphere,two standard deviations lower bound,parts per million,null,climate forcing|paleoceanography,null,null,N,based on planktic foram delta 11B) earth science/paleoclimate/climate reconstructions|paleoceanography (pH,delta 11B,two standard deviations upper bound,dimensionless,null,climate reconstructions|paleoceanography,null,null,N,null) earth science/paleoclimate/climate forcing|paleoceanography (carbon dioxide,bulk atmosphere,two standard deviations upper bound,parts per million,null,climate forcing|paleoceanography,null,null,N,based on planktic foram delta 11B) earth science/paleoclimate/climate reconstructions|paleoceanography (pH,delta 11B,two standard deviations lower bound,dimensionless,null,climate reconstructions|paleoceanography,null,null,N,null) earth science/paleoclimate/climate forcing (ODP 999A>LATITUDE 12.75>LONGITUDE -78.73) Several hypotheses have been put forward to explain the onset of intensive glaciations on Greenland, Scandinavia, and North America during the Pliocene epoch between 3.6 and 2.7 million years ago (Ma). A decrease in atmospheric CO2 may have played a role during the onset of glaciations, but other tectonic and oceanic events occurring at the same time may have played a part as well. Here we present detailed atmospheric CO2 estimates from boron isotopes in planktic foraminifer shells spanning 4.6-2.0 Ma. Maximal Pliocene atmospheric CO2 estimates gradually declined from values around 410 uatm to early Pleistocene values of 300 uatm at 2.0 Ma. After the onset of large-scale ice sheets in the Northern Hemisphere, maximal pCO2 estimates were still at 2.5 Ma +90 uatm higher than values characteristic of the early Pleistocene interglacials. By contrast, Pliocene minimal atmospheric CO2 gradually decreased from 310 to 245 uatm at 3.2 Ma, coinciding with the start of transient glaciations on Greenland. Values characteristic of early Pleistocene glacial atmospheric CO2 of 200 uatm were abruptly reached after 2.7 Ma during the late Pliocene transition. This trend is consistent with the suggestion that ocean stratification and iron fertilization increased after 2.7 Ma in the North Pacific and Southern Ocean and may have led to increased glacial CO2 storage in the oceanic abyss after 2.7 Ma onward. STUDY NOTES: Paleo-CO2 derived from boron isotope measurements on marine sediment core ODP999A for the past 4.6 million years, contributed to the Paleo-pCO2 Database NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Bartoli, G. Investigator : Hönisch, B. Investigator : Zeebe, R.E. 2018-03-10 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/23590 https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/bartoli2011odp999boron.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/bartoli2011odp999boron.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/bartoli2011odp999boron.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/bartoli2011odp999boron.txt English https://www.ncdc.noaa.gov/paleo/study/23590 https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/bartoli2011odp999boron.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/bartoli2011odp999boron.txt Gretta Bartoli, Bärbel Hönisch, Richard E. Zeebe2011Atmospheric CO2 decline during the Pliocene intensification of Northern Hemisphere glaciationsPaleoceanography26410.1029/2010PA002055https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2010PA002055 START YEAR: 4580295 cal yr BP * END YEAR: 1975132 cal yr BP -78.73 12.75 -78.73 12.75