Tertiary Paleobotanical Atmospheric CO2 Reconstruction ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Tertiary Paleobotanical Atmospheric CO2 Reconstruction LAST UPDATE: 3/2006 (Original receipt by WDC Paleo) CONTRIBUTOR: Dana L. Royer, Wesleyan University IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2006-021 SUGGESTED DATA CITATION: Royer, D.L., et al. 2006. Tertiary Paleobotanical Atmospheric CO2 Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2006-021. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Royer, D.L., S.L. Wing, D.J. Beerling, D.W. Jolley, P.L. Koch, L.J. Hickey, and R.A. Berner. 2001. Paleobotanical Evidence for Near Present-Day Levels of Atmospheric CO2 During Part of the Tertiary. Science, vol. 292, pp. 2310-2313, 22 June 2001. ABSTRACT: Understanding the link between the greenhouse gas carbon dioxide (CO2) and Earth's temperature underpins much of paleoclimatology and our predictions of future global warming. Here, we use the inverse relationship between leaf stomatal indices and the partial pressure of CO2 in modern Ginkgo biloba and Metasequoia glyptostroboides to develop a CO2 reconstruction based on fossil Ginkgo and Metasequoia cuticles for the middle Paleocene to early Eocene and middle Miocene. Our reconstruction indicates that CO2 remained between 300 and 450 parts per million by volume for these intervals with the exception of a single high estimate near the Paleocene/Eocene boundary. These results suggest that factors in addition to CO2 are required to explain these past intervals of global warmth. GEOGRAPHIC REGION: Global PERIOD OF RECORD: 58 - 15 MMYrBP FUNDING SOURCES: NSF Graduate Research fellowship (D.L.R.), the Department of Energy grant DE-FGO2-95ER14522 (D.L.R., R.A.B.), and the Smithsonian Institution (S.L.W.). D.J.B. gratefully acknowledges funding through the Natural Environment Research Council, UK award no. GR3/11900, and a Royal Society University Research Fellowship. DESCRIPTION: Paleobotanical (stomatal index, SI) data from North America and Europe, and reconstruction of atmospheric CO2 concentration for parts of the Tertiary: middle Paleocene to early Eocene, and the middle Miocene. DATA: Table 1 a, b. Summary of fossil data. Column 1: Site Column 2: Location Code Column 3: number of leaves measured for calculation of SI. Column 4: Stomatal Index Column 5: CO2(ppmv) Column 6: d13C of organic matter (V-PDB) Location Codes: A = south-central Alberta (Canada) BHB = Bighorn Basin ( Wyoming and Montana, United States) M = Isle of Mull (United Kingdom) I = north-central Idaho (United States). BOM = bulk organic matter Dashes indicate that no analyses were performed 1a. Ginkgo Site Location Age(Ma) n SI(%) CO2(ppmv) d13Com (V-PDB) Burbank A 58.5 7 7.55 450 - Joffre Bridge A 58.5 5 7.96 391 - SLW 0025 BHB 57.3 7 9.01 340 - LJH 7132 BHB 56.4 5 8.75 348 -23.91 SLW 991 BHB 55.9 5 10.97 314 - SLW 992 BHB 55.9 8 10.8 316 -25.66 SLW 993 BHB 55.9 8 11.43 311 - LJH 72141-1 BHB 55.8 12 10.63 317 - SLW 9155 BHB 55.7 10 11.21 313 -29.8 SLW 9411 BHB 55.6 8 11.5 311 -23.77 SLW 9434 BHB 55.4 7 12.23 307 -22.53 SLW 9715 BHB 55.3 12 8.23 371 -24.17 SLW 9050 BHB 55.3 5 12.18 308 -26.99 SLW 9936 BHB 55.3 15 11.77 310 - SLW 8612 BHB 55.3 7 12.41 307 - Ardtun Head M 55.2 13 6.54 798 -24.68 AR-2 (BOM) -24.56 AR-6 (BOM) -25.82 AR-8 (BOM) -24.17 AR-10 (BOM) -24.26 AR-15 (BOM) -24.54 SLW 9812 BHB 55.1 22 8.53 356 -24.49 SLW 9915 BHB 54.8 8 8.83 345 - SLW LB BHB 53.9 5 9.29 334 - SLW H BHB 53.5 9 10.22 321 -26.93 LJH 9915 BHB 53.4 15 9.38 332 -26.33 1b. Metasequoia Site Location Age(Ma) n SI(%) CO2(ppmv) d13Com (V-PDB) Juliaetta (P6) I 16.5 14 8.14 377 - Metasequoia Clarkia (P33a) I 15.3 6 11.59 307 - Clarkia (P33b) I 15.3 10 10.94 316 - P37a I 15.2 10 10.95 316 -