noaa-forcing-20485 LOSCAR Model Paleocene-Eocene Thermal Maximum d13C Onset Output Zeebe, R.E.; Ridgwell, A.; Zachos, J.C. LOSCAR Model Paleocene-Eocene Thermal Maximum d13C Onset Output 2016-09-06 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/20485 Investigator R.E. Zeebe Investigator A. Ridgwell Investigator J.C. Zachos earth science paleoclimate paleoclimatic modeling delta 13C,dissolved inorganic carbon,null,per mil VPDB,null,paleoclimatic modeling,null,null,N,null earth science paleoclimate climate forcing geoscientificInformation 56000000 cal yr BP 55990000 cal yr BP Complete -90 90 -180 180 Geographic Region Global Global>LATITUDE >LONGITUDE 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 Zeebe, R.E., A. Ridgwell and J.C. Zachos 2016 Nature Geoscience 9 4 10.1038/NGEO2681

Carbon release rates from anthropogenic sources reached a record high of ~10 Pg C yr-1 in 2014. Geologic analogues from past transient climate changes could provide invaluable constraints on the response of the climate system to such perturbations, but only if the associated carbon release rates can be reliably reconstructed. The Palaeocene–Eocene Thermal Maximum (PETM) is known at present to have the highest carbon release rates of the past 66 million years, but robust estimates of the initial rate and onset duration are hindered by uncertainties in age models. Here we introduce a new method to extract rates of change from a sedimentary record based on the relative timing of climate and carbon cycle changes, without the need for an age model. We apply this method to stable carbon and oxygen isotope records from the New Jersey shelf using time-series analysis and carbon cycle–climate modelling. We calculate that the initial carbon release during the onset of the PETM occurred over at least 4,000 years. This constrains the maximum sustained PETM carbon release rate to less than 1.1 Pg C yr-1. We conclude that, given currently available records, the present anthropogenic carbon release rate is unprecedented during the past 66 million years. We suggest that such a ‘no-analogue’ state represents a fundamental challenge in constraining future climate projections. Also, future ecosystem disruptions are likely to exceed the relatively limited extinctions observed at the PETM. STUDY NOTES: d13C-DIC surface output for the onset of the Palaeocene-Eocene Thermal Maximum from LOSCAR model (Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir Model) Model run is for 10,000 y after Paleocene-Eocene boundary (~56 Ma) with a 3,000 Pg C release stretched over 4,000 years.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/loscar-petm-d13C.txt Formatted Text File; d13C Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11