noaa-recon-22992 North America and Europe Holocene Gridded Temperature Reconstructions Marsicek, J.P.; Shuman, B.N.; Bartlein, P.J.; Shafer, S.; Brewer, S. North America and Europe Holocene Gridded Temperature Reconstructions 2018-02-01 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/22992 Investigator J.P. Marsicek Investigator B.N. Shuman Investigator P.J. Bartlein Investigator S. Shafer Investigator S. Brewer earth science paleoclimate climate reconstructions|pollen temperature,null,null,degree Celsius,coldest month,climate reconstructions|pollen,anomalized|averaged,null,N,averaged to century mean; anomalies relative to the mean of 1450-1950 AD earth science paleoclimate climate reconstructions|pollen temperature,null,null,degree Celsius,annual,climate reconstructions|pollen,anomalized|averaged,null,N,averaged to century mean; North America earth science paleoclimate climate reconstructions|pollen temperature,null,null,degree Celsius,annual,climate reconstructions|pollen,anomalized|averaged,null,N,averaged to century mean; Europe earth science paleoclimate climate reconstructions|pollen longitude,null,null,degree east,null,climate reconstructions|pollen,null,null,N,null earth science paleoclimate climate reconstructions age,null,null,year Common Era,null,climate reconstructions,null,null,N,null earth science paleoclimate climate reconstructions|pollen temperature,null,null,degree Celsius,annual,climate reconstructions|pollen,anomalized|averaged,null,N,averaged to century mean; Northern Hemisphere earth science paleoclimate climate reconstructions|pollen growing degree days,null,null,kelvin day,null,climate reconstructions|pollen,anomalized|averaged,null,N,averaged to century mean; growing degree days above a 5 degree Celsius base as anomalies relative to the mean of 1450-1950 AD earth science paleoclimate climate reconstructions|pollen latitude,null,null,degree north,null,climate reconstructions|pollen,null,null,N,null earth science paleoclimate reconstructions air temperature geoscientificInformation Air Temperature Reconstruction 11000 cal yr BP 0 cal yr BP Complete 25 70 -170 40 Continent Europe Europe>LATITUDE >LONGITUDE Continent North America North America>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 Jeremiah Marsicek, Bryan N. Shuman, Patrick J. Bartlein, Sarah L. Shafer, Simon Brewer 2018 Nature 554 92-96 10.1038/nature25464 https://www.nature.com/articles/nature25464

Cooling during most of the past two millennia has been widely recognized and has been inferred to be the dominant global temperature trend of the past 11,700 years (the Holocene epoch). However, long-term cooling has been difficult to reconcile with global forcing, and climate models consistently simulate long-term warming. The divergence between simulations and reconstructions emerges primarily for northern mid-latitudes, for which pronounced cooling has been inferred from marine and coastal records using multiple approaches. Here we show that temperatures reconstructed from sub-fossil pollen from 642 sites across North America and Europe closely match simulations, and that long-term warming, not cooling, defined the Holocene until around 2,000 years ago. The reconstructions indicate that evidence of long-term cooling was limited to North Atlantic records. Early Holocene temperatures on the continents were more than two degrees Celsius below those of the past two millennia, consistent with the simulated effects of remnant ice sheets in the climate model Community Climate System Model 3 (CCSM3). CCSM3 simulates increases in 'growing degree days' - a measure of the accumulated warmth above five degrees Celsius per year - of more than 300 kelvin days over the Holocene, consistent with inferences from the pollen data. It also simulates a decrease in mean summer temperatures of more than two degrees Celsius, which correlates with reconstructed marine trends and highlights the potential importance of the different subseasonal sensitivities of the records. Despite the differing trends, pollen- and marine-based reconstructions are correlated at millennial-to-centennial scales, probably in response to ice-sheet and meltwater dynamics, and to stochastic dynamics similar to the temperature variations produced by CCSM3. Although our results depend on a single source of palaeoclimatic data (pollen) and a single climate-model simulation, they reinforce the notion that climate models can adequately simulate climates for periods other than the present-day. They also demonstrate that amplified warming in recent decades increased temperatures above the mean of any century during the past 11,000 years. STUDY NOTES: Gridded, pollen-based climate reconstructions (mean annual temperature, growing degree days, and mean temperature of the coldest month) for North America and Europe over the Holocene.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/marsicek2018/ Data Folder; Europe and North America Holocene Temperature Reconstructions USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11