noaa-forcing-26151 Paleo-pCO2 Database Early Miocene Stomata CO2 Data Londoño, L.; Royer, D. Paleo-pCO2 Database Early Miocene Stomata CO2 Data 2019-02-07 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/26151 Investigator L. Londoño Investigator D. Royer earth science paleoclimate climate forcing carbon dioxide geoscientificInformation 18300000 cal yr BP 18100000 cal yr BP Complete 9 9 -79.61 -79.61 Continent North America Central America Panama Pedro Miguel Formation>LATITUDE 9>LONGITUDE -79.61 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 Liliana Londoño, Dana L. Royer, Carlos Jaramillo, Jaime Escobar, David A. Foster, Andrés L. Cárdenas-Rozo, Aaron Wood 2018 American Journal of Botany 105 11 1929-1937 10.1002/ajb2.1187 https://bsapubs.onlinelibrary.wiley.com/doi/abs/10.1002/ajb2.1187

Premise of the Study The global climate during the early Miocene was warmer than the present and preceded the even warmer middle Miocene climatic optimum. The paleo-CO2 records for this interval suggest paradoxically low concentrations (<450 ppm) that are difficult to reconcile with a warmer-than-present global climate. Methods In this study, we use a leaf gas-exchange model to estimate CO2 concentrations using stomatal characteristics of fossil leaves from a late early Miocene Neotropical assemblage from Panama that we date to 18.01 ± 0.17 Ma via 238U/206Pb zircon geochronology. We first validated the model for Neotropical environments by estimating CO2 from canopy leaves of 21 extant species in a natural Panamanian forest and from leaves of seven Neotropical species in greenhouse experiments at 400 and 700 ppm. Key Results The results showed that the most probable combined CO2 estimate from the natural forests and 400 ppm experiments is 475 ppm, and for the 700 ppm experiments is 665 ppm. CO2 estimates from the five fossil species exhibit bimodality, with two species most consistent with a low mode (528 ppm) and three with a high mode (912 ppm). Conclusions Despite uncertainties, it is very likely (at >95% confidence) that CO2 during the late early Miocene exceeded 400 ppm. These results revise upwards the likely CO2 concentration at this time, more in keeping with a CO2-forced greenhouse climate. STUDY NOTES: Stomata Paleo-CO2 data from Londoño 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/londono2018stomata_franks.txt NOAA Template File; Early Miocene Stomata CO2 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/londono2018stomata_franks.xlsx Excel File; Early Miocene Stomata CO2 Data USA/NOAA DIF Version 9.8.4 2019-02-15 2019-02-15