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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. Measurement(s) climate Technology Type(s) digital curation Factor Type(s) temporal interval • geographic location • proxy type Sample Characteristic - Environment climate system Sample Characteristic - Location Earth (planet) Machine-accessible metadata file describing the reported data: https://www.ncdc.noaa.gov/paleo/study/27330 [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine levels of food security among American Indians (AI) living in the Midwest and possible correlations between food security levels and various health outcomes, diet, and demographic variables. This study used a cross-sectional design to determine health behaviors among AI. Participants (n = 362) were recruited by AI staff through various cultural community events in the Midwest, such as powwows and health fairs. Inclusion criteria included the following: age 18 years or older, self-identify as an AI, and willing to participate in the survey. Of all participants, 210 (58%) had either low or very low food security, with 96 in the very low category (26.5%). Participants with very low food security tended to have significantly more chronic conditions. Additional significant differences for very low food security existed by demographic variables, including having no insurance (p < 0.0001) or having a regular primary care provider (p = 0.0354). There was also a significant difference between food security levels and the consumption of fast food within the past week (p value = 0.0420), though no differences were found in fruit and vegetable consumption. AI in our sample had higher levels of food insecurity than those reported in the literature for other racial/ethnic groups. AI and non-Native health professionals should be aware of the gravity of food insecurity and the impact it has on overall health. Additional research is needed to determine specific aspects of food insecurity affecting different Native communities to develop appropriate interventions. [ABSTRACT FROM AUTHOR]

We present an 8000-year biomarker and stable carbon isotope record from the Verlorenvlei Estuary, South Africa. We assessed how leaf wax lipids, insoluble macromolecular organic matter, bulk C/N data and compound-specific stable carbon isotopes were linked to the site's palynological record and to evidence for regional sea level and environmental change. Down-core trends in bulk δC are closely coupled to trends in pollen types from saline-tolerant taxa. These trends are mirrored by variations in the incorporation of reduced sulphur into macromolecular organic matter. This process, quantified with the thiophene ratio, is closely associated with periods of higher sea level 8,000-4,300 cal yr BP. We propose the thiophene ratio is a proxy for relative marine influence within (peri) estuarine sediments. All measured variables indicate differences between early-middle Holocene (8,000-4,300 cal BP) and late Holocene conditions at Verlorenvlei. The former period was more saline and preserves more labile macromolecular organic matter. Marine influence declined after 4,300 cal yr BP, and although the abundance of short-chain-length n-alkanes suggests continued presence of wetland flora until 2,500 cal yr BP, organic matter preservation became poorer and a drying trend was inferred, most notably for the interval 2,500-900 cal BP. Increasing freshwater inundation is apparent during the last 700 cal yr, consistent with several records from this region. Leaf wax n-alkane distributions are largely uncorrelated with bulk organic matter variables, with the exception of the abundance of C and C n-alkanes, which are negatively correlated with δC. Furthermore, C-C n-alkane δC values are uncorrelated with C-C δC and δC. They are also higher than our newly measured terrestrial (C) vegetation C and C end-member values of −35 ± 2 and −34 ± 1 ‰, respectively. These patterns are best explained by a dominant contribution of local riparian vegetation to the C-C n-alkanes, but time-varying contributions of non-local leaf waxes to the C-C signals. This renders inferences concerning regional environmental change from long-chain leaf waxes potentially challenging in this setting. [ABSTRACT FROM AUTHOR]

Pyrolysis-gas chromatography mass spectrometry (py-GC/MS) allows the characterisation of complex macromolecular organic matter. In lakes and wetlands this can potentially be used to assess the preservation/diagenesis and provenance of sediment organic matter. It can complement palaeoenvironmental investigations utilising 'bulk' sediment variables such as total organic carbon (TOC) and TOC/total nitrogen ratios. We applied py-GC/MS analyses to a ~32,000-year sediment record from the southern Cape coastline of South Africa. We used the results to evaluate the sources and extent of degradation of organic matter in this semi-arid environment. Marked down-core changes in the relative abundance of multiple pyrolysis products were observed. Correspondence analysis revealed that the major driver of this down-core variability in OM composition was selective preservation/degradation. Samples comprising highly degraded OM are primarily confined to the lower half of the core, older than ~12,000 years, and are characterised by suites of low-molecular-weight aromatic pyrolysis products. Samples rich in organic matter, e.g. surface sediments, are characterised by products derived from fresh emergent or terrestrial vegetation, which include lignin monomers, plant-derived fatty acids and long-chain n-alkanes. Pyrolysates from the late glacial-early Holocene period, approximately mid-way down the core are characterised by distinct suites of long-chain n-alkene/ n-alkane doublets, which may reflect the selective preservation of recalcitrant aliphatic macromolecules and/or enhanced inputs of the algal macromolecule algaenan/polymerised algal lipids. Increased TOC, lower δC and increased abundance of more labile lignin and fatty acid products at the same depths suggest this period was associated with increased lake primary productivity and enhanced inputs of terrestrial OM. TOC is the only 'bulk' parameter correlated with the correspondence analysis axes extracted from the py-GC/MS data. Distinct fluctuations in TOC/total nitrogen ratio are not explained by variation in organo-nitrogen pyrolysis products. Notwithstanding, the study suggests that py-GC/MS has potential to complement palaeolimnological investigations, particularly in regions such as southern Africa, where other paleoenvironmental proxy variables in sediments may be lacking or equivocal. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]