ALBERT

Description: As climate model uncertainties remain very large for future rainfall in the Sahel, a multi-centennial perspective is required to assess the situation of current Sahel climate in the context of global warming. We present here the first record of hydroclimatic variability over the past 1600 years in Senegal, obtained from stable oxygen isotope analyses (δ18O) in archaeological shell middens from the Saloum Delta. During the preindustrial period, the region was relatively humid, with maximum humidity reached during the period from AD 1500 to AD 1800, referred to as the Little Ice Age. A significant negative link is observed at the centennial scale between global temperature and humidity in the Sahel that is at odds with the expected effects of latitudinal shifts of the intertropical convergence zone during the last millennium. In the context of the past 1600 years, the Western Sahel appears to be experiencing today unprecedented drought conditions. The rapid aridification that started ca. AD 1800 and the recent emergence of Sahel drought from the natural variability point to an anthropogenic forcing of Sahel drying trend. This new long-term perspective suggests that the recovery of Sahel rainfall in the last decade may only result from short-term internal variability, and supports climate models that predict an increase of Sahel drought under future greenhouse climate.

Description: Movies: for all mapped movies (movie S1 - S6): white circles indicate the presence of a pollen record; blue dots indicate archaeological remains of wild terrestrial ungulates; and red dots indicate the remains of domestic animals. The distribution of the faunal remains was based on summed probability distributions of radiocarbon dates at 100-year time intervals (see Phelps et al. in press for further methodological information). Movie S1a: The climatic envelope of forest mapped at 100-year intervals, using the direct methodology with WorldClim data (black background). Movie S1b: The climatic envelope of forest mapped at 100-year intervals, using the direct methodology with WorldClim data (white background). Movie S1c: The climatic envelope of forest mapped at 100-year intervals, using the direct methodology with TraCE-21ka climate information (black background). Movie S1d: The climatic envelope of forest taxa mapped at 100-year intervals, using the direct methodology with TraCE-21ka climate information (white background). Movie S1e: The climatic envelope of forest taxa mapped at 100-year intervals, using the indirect methodology, WorldClim data (black background). Movie S1f: The climatic envelope of forest taxa mapped at 100-year intervals, using the indirect methodology, WorldClim data (white background). Movie S1g: The climatic envelope of forest taxa mapped at 100-year intervals, using the indirect methodology, TraCE-21ka climate information (black background). Movie S1h: The climatic envelope of forest taxa mapped at 100-year intervals, using the indirect methodology, TraCE-21ka climate information (white background). ______________________________________________________________________________________ Movie S2a: The climatic envelope of grassy biomes (savanna- and steppe-associated taxa) mapped at 100-year intervals, using the direct methodology with WorldClim data (black background). Movie S2b: The climatic envelope of grassy biomes (savanna- and steppe-associated taxa) mapped at 100-year intervals, using the direct methodology with WorldClim data (white background). Movie S2c: The climatic envelope of grassy biomes (savanna- and steppe-associated taxa) mapped at 100-year intervals, using the direct methodology with TraCE-21ka climate information (black background). Movie S2d: The climatic envelope of grassy biomes (savanna- and steppe-associated taxa) mapped at 100-year intervals, using the direct methodology with TraCE-21ka climate information (white background). ______________________________________________________________________________________ Movie S3a: The climatic envelope of savanna-associated taxa mapped at 100-year intervals, using the indirect methodology, WorldClim data (black background). Movie S3b: The climatic envelope of savanna-associated taxa mapped at 100-year intervals, using the indirect methodology, WorldClim data (white background). Movie S3c: The climatic envelope of savanna-associated taxa mapped at 100-year intervals, using the indirect methodology, TraCE-21ka climate information (black background). Movie S3d: The climatic envelope of savanna-associated taxa mapped at 100-year intervals, using the indirect methodology, TraCE-21ka climate information (white background). ______________________________________________________________________________________ Movie S4a: The climatic envelope of steppe-associated taxa mapped at 100-year intervals, using the indirect methodology, WorldClim data (black background). Movie S4b: The climatic envelope of steppe-associated taxa mapped mapped at 100-year intervals, using the indirect methodology, WorldClim data (white background). Movie S4c: The climatic envelope of steppe-associated taxa mapped mapped at 100-year intervals, using the indirect methodology, TraCE-21ka climate information (black background). Movie S4d: The climatic envelope of steppe-associated taxa mapped mapped at 100-year intervals, using the indirect methodology, TraCE-21ka climate information (white background). ______________________________________________________________________________________ Movie S5a: The climatic envelope of desert-associated taxa mapped mapped at 100-year intervals, using the direct methodology with WorldClim data (black background). Movie S5b: The climatic envelope of desert-associated taxa mapped at 100-year intervals, using the direct methodology with WorldClim data (white background). Movie S5c: The climatic envelope of desert-associated taxa mapped at 100-year intervals, using the direct methodology with TraCE-21ka climate information (black background). Movie S5d: The climatic envelope of desert-associated taxa mapped at 100-year intervals, using the direct methodology with TraCE-21ka climate information (white background). Movie S5e: The climatic envelope of desert-associated taxa mapped at 100-year intervals, using the indirect methodology, WorldClim data (black background). Movie S5f: The climatic envelope of desert-associated taxa mapped at 100-year intervals, using the indirect methodology, WorldClim data (white background). Movie S5g: The climatic envelope of desert-associated taxa mapped at 100-year intervals, using the indirect methodology, TraCE-21ka climate information (black background). Movie S5h: The climatic envelope of desert-associated taxa mapped at 100-year intervals, using the indirect methodology, TraCE-21ka climate information (white background). ______________________________________________________________________________________ Movie S6a: The climatic envelope of xeric-associated taxa mapped at 100-year intervals, using the direct methodology with WorldClim data (black background). Movie S6b: The climatic envelope of xeric-associated taxa mapped at 100-year intervals, using the direct methodology with WorldClim data (white background). Movie S6c: The climatic envelope of xeric-associated taxa mapped at 100-year intervals, using the direct methodology with TraCE-21ka climate information (black background). Movie S6d: The climatic envelope of xeric-associated taxa mapped at 100-year intervals, using the direct methodology with TraCE-21ka climate information (white background). Movie S6e: The climatic envelope of xeric-associated taxa mapped at 100-year intervals, using the indirect methodology, WorldClim data (black background). Movie S6f: The climatic envelope of xeric-associated taxa mapped at 100-year intervals, using the indirect methodology, WorldClim data (white background). Movie S6g: The climatic envelope of xeric-associated taxa mapped at 100-year intervals, using the indirect methodology, TraCE-21ka climate information (black background). Movie S6h: The climatic envelope of xeric-associated taxa mapped at 100-year intervals, using the indirect methodology, TraCE-21ka climate information (white background). ______________________________________________________________________________________ Movie S7a: Multivariate environmental similarity surface (MESS) analyses plotted in geographic space using the direct methodology with repeated, modern-day WorldClim data. White areas demonstrate neutrality: i.e., neither similarity nor dissimilarity. Movie S7b: Multivariate environmental similarity surface (MESS) analyses plotted in geographic space using the direct methodology with TraCE-21ka climate information. White areas demonstrate neutrality: i.e., neither similarity nor dissimilarity. Movie S7c: Multivariate environmental similarity surface (MESS) analyses plotted in geographic space using the indirect methodology with repeated, modern-day WorldClim data. White areas demonstrate neutrality: i.e., neither similarity nor dissimilarity. Movie S7d: Multivariate environmental similarity surface (MESS) analyses plotted in geographic space using the indirect methodology with TraCE-21ka climate information. White areas demonstrate neutrality: i.e., neither similarity nor dissimilarity. ______________________________________________________________________________________ Movie S8a: Climatic envelope overlap between forest and grassy biomes (savanna and steppe) plotted in climate space. Envelopes were generated using the direct methodology and TraCE-21ka climate information. Red areas indicate the presence of grassy biomes only, whereas purple indicates overlap between grassy biomes and forest. For reference to the climatic variables used to define the climate space, see the TraCE-21ka correlation circle in figure A2. Movie S8b: Climatic envelope overlap between forest and savanna only, plotted in climate space. Envelopes were generated using the indirect methodology and TraCE-21ka climate information. Red areas indicate the presence of savanna only, whereas purple indicates overlap between savanna and forest. For reference to the climatic variables used, see the TraCE-21ka correlation circle in figure A2.

Description: The Eurasian Modern Pollen Database (EMPD) contains modern pollen data (raw counts) for the entire Eurasian continent. Derived from the European Modern Pollen Database, the dataset contains many more samples West of the Ural Mountains. We propose this dataset in three different format: 1/ an Excel spreadsheet, 2/ a PostgreSQL dump and 3/ a SQLite3 portable database format. All three datasets are strictly equivalent. For download see "Original Version".

Description: This dataset contains the best climate estimate for each sample. Under Other version, the xlsx file contains the 1) pollen counts used to produce the reconstruction (Pickarski, N. et al., 2015a,b), 2) the best climate estimate for each sample, and 3) the full posterior probabilistic distribution of each sample (as used to generate figure 3 of the associated paper).

Description: This dataset contains the best estimates for Mean Annual Temperature Reconstructions from marine core MD96-2048. Under Other version, the xlsx file contains the 1) best estimates for Mean Annual Temperature Reconstructions, 2) posterior distribution of probabilities for each sample, 3) conversion table of plant species to pollen taxa, 4) percentage data used in the reconstruction, 5) list of selected and excluded pollen taxa.

Description: This dataset is associated with Phelps et al. (2020, DOI: 10.1111/ecog.04990), and is comprised of paleoecological information from African subfossil pollen assemblages over the past 20,000 years. Data includes the following information: Appendix 1: a list of collated sites from the APD, EPD, and other publications Appendix 2: a list of collated entities from the APD, EPD, and other publications Appendix 3: a list of citations for each entity in appendix 2, whether analyzed or not Appendix 4: a harmonized taxa list with original taxa names and numbers Appendix 5: a list of collated samples from the APD, EPD, and other publications Appendix 6: a list of counts from the APD, EPD, ACER, and other publications Appendix 7: a list of dates (14C, etc) from the APD, EPD, ACER, and other publications Appendix 8: a list of CLAM outputs calculated (Blaauw 2010) from the list of radiocarbon dates Appendix 9: a harmonized biomization scheme for "direct" and "indirect" methods For use of these datasets, associated publications (see appendix 3) and databases should be cited: The African Pollen Database (APD: Vincens et al. 2007, http://fpd.sedoo.fr/fpd/bibli.do) The European Pollen Database (EPD: Fyfe et al. 2009, http://www.europeanpollendatabase.net/getdata/) The ACER Pollen and Charcoal Database (Sánchez Goñi et al. 2017) Additional information was added to these appendices in association with the following publications (note: information was extracted from publications and/or contributed by authors): Brenac 1988, Burrough & Willis 2015, Chase et al. 2015b, Cheddadi et al. 2015, 2016, 2017, Cordova et al. 2017, Giresse et al. 1994, Lim et al. 2016, Maley 1991, Maley & Brenac 1998, Metwally et al. 2014, Quick et al. 2016, 2018, Valsecchi et al. 2013, Waller et al. 2007. The harmonized biomization scheme (appendix 9), is based on six primary publications: Jolly et al. 1998, Elenga et al. 2000, Vincens et al. 2006, Vincens et al. 2007, Lebamba et al. 2009, Lézine et al. 2009, with reference to the African Plant Database (version 3.4.0).

Description: A comprehensive database of paleoclimate records is needed to place recent warming into the longer-term context of natural climate variability. We present a global compilation of quality-controlled, published, temperature-sensitive proxy records extending back 12,000 years through the Holocene. Data were compiled from 679 sites where time series cover at least 4000 years, are resolved at sub-millennial scale (median spacing of 400 years or finer) and have at least one age control point every 3000 years, with cut-off values slackened in data-sparse regions. The data derive from lake sediment (51%), marine sediment (31%), peat (11%), glacier ice (3%), and other natural archives. The database contains 1319 records, including 157 from the Southern Hemisphere. The multi-proxy database comprises paleotemperature time series based on ecological assemblages, as well as biophysical and geochemical indicators that reflect mean annual or seasonal temperatures, as encoded in the database. This database can be used to reconstruct the spatiotemporal evolution of Holocene temperature at global to regional scales, and is publicly available in Linked Paleo Data (LiPD) format.