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Paleotempestology, the study of past tropical cyclone activity, has grown considerably over the past two decades, and there is now a relatively dense network of sites across the Western North Atlantic Basin providing records of past tropical cyclone variability. This paper presents a new database of paleotempestological records generated from 61 studies published between 1993 and 2018 for this region. A total of 266 data entries, consisting of the calibrated ages of individual tropical cyclone events and the boundaries of ‘active’ tropical cyclone periods from the present to 8000 cal. yr BP, along with the site names, geographic coordinates, proxy indicator(s) used, materials upon which dating was undertaken, and information about the depositional basin type (e.g. lagoon, mangrove), are included in the database for each site. The database is housed at the National Oceanographic and Atmospheric Association (NOAA) (https://www.ncdc.noaa.gov/paleo/study/21391) and is available for free download. This publicly available database will permit a greater number of researchers to work on questions related to past tropical cyclone dynamics and more easily allow studies of long-term spatial-temporal tropical cyclone relationships to be undertaken. [ABSTRACT FROM AUTHOR]

This paper reviews the reconstruction of European Atlantic storm events with the contribution of a new stormy reconstruction in its central part. Three marsh environments on the island of Yeu were chosen to identify disturbing storm events from the Mid- to Late Holocene with vibracore sampling, radiocarbon dating and sedimentary analysis. Nine probable intervals of high energy deposition in these low-transport-activity environments are estimated: 600–500, near 1590, 2100–1950, 2850–2350, 3500–3270, 5400–5370, 6650–6510, near 7000 and between 7670 and 7470 calibrated years before present (cal y BP). By comparison with sedimentological paleostorm studies, we confirm six European Atlantic storm events estimated at near 600–300, 1700–1100, 2900–2500, 3500–3300, 5500–5100 and 7700–7100 cal y BP, corresponding to worldwide Holocene cooling climatic periods. A comparison with other storminess reviews of worldwide main stormy coasts shows that Holocene storms can increase during global cooling periods in the northern hemisphere. [ABSTRACT FROM AUTHOR]

This paper presents an integrated approach to assess Holocene environmental changes in the Sperchios delta, Sperchios rift, central Greece. A multidisciplinary study was carried out applying established analytical methods as well as exploring new techniques to detect past environmental conditions in a fluvio-deltaic depositional system. A series of six deep boreholes, up to 50 m long, and four shallow cores, up to 6 m long, from across the delta plain, were studied in detail. Sedimentary facies were defined by changes in grain size and macro- and microfaunal composition. Variability in mineral magnetic composition documented by changes in bulk magnetic susceptibility (χ and χ77K/χ293K) and remanence parameters (S−300 and σARM/σSIRM ratios), as well as down-core elemental variations obtained by scanning micro-x-ray fluorescence (µ-XRF), provide constraints on the depositional changes related to the evolution of the Sperchios delta. Correlations between elemental data derived by µ-XRF analyses and grain size were also analyzed and used to further constrain the facies interpretation. Overall, these Holocene sediments reveal a transgressive–regressive succession overlying pre-transgressive terrestrial deposits of Late Pleistocene–Early Holocene age. Furthermore, 13 new 14C radiocarbon dates constrain the transgression rate to be ~3.5 m/yr for the Early Holocene and the regression rate to be ~1 m/yr for the Late Holocene. The Sperchios delta plain developed when the rate of sea-level rise decreased ~6000 cal. yr BP as it has been proposed for the broader area of Aegean Sea. This study demonstrates that the combination of techniques used here provides a powerful way to map out paleoenvironmental changes and thus the 3D stratigraphic architecture of Holocene sedimentary successions. [ABSTRACT FROM AUTHOR]

Bleicher (2013) discussed interpretations proposed by Magny (2004) that Holocene lake-level fluctuations in west-central Europe suggest possible solar forcing of climate. He pointed out that the method used by Magny (2004) is a variant of a cumulative probability function (CPF) and cannot prove solar forcing of central European lake-level changes. He concluded that only few episodes of lake-level changes are climatically driven and that non-climatic factors were dominating. While Bleicher’s paper offers a stimulating contribution to the general debate on CPFs, the present comment is based on an approach which, in contrast to CPFs, excludes any consideration of variations in the probabilities over the time intervals given by calibration of 14C dates, as well as any distinction between types of dates (radiocarbon versus tree ring). It produces a revised pattern of the mid-European high lake-level events for the whole Holocene, supporting the hypothesis proposed in Magny (2004). Comparisons with other regional and North Atlantic palaeoclimatic records suggest that, without excluding other forcing factors, the successive high lake-level events recognised in west-central Europe reflect a combination of three main forcing factors acting on millennial and centennial scales, i.e. orbitally driven changes in insolation, impacts of deglacial outbursts and, possibly, variations in solar activity. Finally, it is clear that further investigations are still needed in order to improve the chronological data set for mid-European lake-level fluctuations, with particular attention to better defining the beginning and end of events. [ABSTRACT FROM AUTHOR]

Basin water in deep-silled Norwegian fjords is primarily influenced by inflowing Atlantic water originating from the Norwegian Atlantic Current (NwAC). Previous studies suggest that benthic foraminiferal oxygen isotope records from such fjords are strongly influenced by variability in this current. The present paper presents a mid- to late-Holocene record (6–2.2 ka) with 17-yr time resolution from a western Norwegian deep-silled fjord, Voldafjorden. An age model, based on ten AMS radiocarbon dates on marine carbonates and on one plant macrofossil, has been established. The study focuses on the oxygen isotope results, obtained from two species of benthic foraminifera: Cassidulina laevigata and Uvigerina mediterranea. The δ18O C. laevigata record has systematically larger amplitudes than the δ18O U. mediterranea record, which most likely is related to different life cycles/periods of calcification. The oxygen isotope results show a clear shift towards higher values between 5 and 4 ka, interpreted to reflect a temperature drop in the basin water of c. 1°C. After the temperature drop, the high frequency variability (centennial and multidecadal) changes abruptly towards larger amplitudes. This corresponds to changes in subperiodicity, where a 370 year cycle in the δ18O C. laevigata record disappears after 3.8 ka. The δ18O transition corresponds to changes in carbon isotopes and grain size distribution, suggesting that a more extensive change in the fjord environment occurred after the cooling. The timing of the oxygen isotope shift towards higher values and the transition in high frequency variability correspond to major changes recorded in paleoclimate archives within the North Atlantic region and globally. [ABSTRACT FROM AUTHOR]

This paper provides a synthesis of available palynological data from central Mediterranean lacustrine records, studying the causes of the important vegetation changes which occurred in the mid Holocene. They are illustrated by seven well-dated records, lakes Accesa, Mezzano, Vico, and Pergusa in Italy, Maliq, Voulkaria and Malo J. in the Balkans. A good tool for disentangling climate change and human impact is the combined interpretation of pollen percentage and concentration/influx data. Pollen concentration/influx drops are an indication of increased erosion in the catchment, mainly ascribable to forest reduction. There is no doubt that major synchronous changes could not have been caused by humans alone. Many southern European records show substantial differences between early- and late-Holocene vegetation, suggesting a general evolution from wetter to drier climatic conditions, in agreement with arid phases recognised by other, independent palaeoclimatic methods. Other pollen records show a different trend. The role of changing seasonality seems important for this region of the Mediterranean. Precipitation seasonality increased during the early to mid Holocene with winter precipitation attaining a maximum, and summer precipitation a minimum. At least three rapid climate events with changes in plant biomass are in evidence: an abrupt and short change around 8200 yr BP, another one centred around 6000 yr BP, and one soon after 3000 yr BP. From the beginning of the Bronze Age (c. 4400 yr BP in this region) human impact overlapped with a climate change, probably bipartite, towards dryness. Our results show that this aridification trend began around 8000 yr BP, and culminated around 4000 yr BP. [ABSTRACT FROM AUTHOR]

This paper presents and discusses the use of soil charcoal analysis (pedoanthracology) to reconstruct past forest dynamics in a larch forest of the upper Guil valley (French Alps, Queyras). We also discuss the role of anthropogenic fire in forest dynamics. The radiocarbon dates from this site demonstrate that arolla pine (Pinus cembra) and larch were present in the area since 7566-7673 cal. BP and 5934-6123 cal. BP, respectively. The identification of a piece of charcoal to fir (Abies alba) dated to 5734-5908 cal. BP suggests that this species was present at 1980 m a.s.l. since c. 6000 cal. BP and had a higher ecological tolerance than previously assumed. The cover of larch forests has increased since the second half of the Holocene because of anthropogenic practices (eg, clearing with fire, cattle grazing). However, today, owing to the abandonment of pastoral practices, the arolla pine has become dominant, which greatly modifies the forest structure and the landscape. [ABSTRACT FROM AUTHOR]

River basins in Great Britain and Ireland have been characterized by periods of hillslope and valley floor instability during the Holocene, reflecting sensitivity to both climate change and anthropogenic disturbance. In contrast to climatic controls, which have been relatively well documented, human impacts on and interactions with river basins remain unclear. There is now, however, a growing impetus to elucidate more fully the impact of anthropogenic activity on sediment supply and runoff, given that land-use change is thought to have exacerbated recent flooding in the UK (eg, the 'Millennium' floods of 2000). The aim of this paper is to critically review the significance of Holocene land use on hillslope and valley floor stability in Great Britain and Ireland. The most widely reported impacts of land-use change on geomorphic activity include hillslope erosion and gully development, valley floor alluviation, river channel incision and elevated water tables. In the majority of cases, however, causal relationships are difficult to establish, due primarily to inadequate dating control. Even where geomorphic instability can be linked to land-use change, it is apparent that eroded material is often stored as colluvium, which together with evidence of diachronus hillslope and valley floor instability, raises important questions and identifies uncertainties regarding the dynamics and extent of sediment transfer within river basins. Such uncertainty has important implications for understanding how river basins will behave in response to future environmental change. [ABSTRACT FROM AUTHOR]

Relative sea-level changes in southwest Britain are poorly constrained because of limitations in the quality and quantity of existing geological data. As a consequence, in contrast to most other regions in the UK, it is not possible to reliably infer rates of land and sea-level change during the last few thousand years. Furthermore, geologically based sea-level reconstructions from this area display significant misfits with relative sea-level predictions based on a recent global model of the glacio-isostatic adjustment process. This paper presents a new record of relative sea-level change for the last 4000 years derived from radiocarbon-dated sea-level index points. In addition to providing information concerning the pattern and rates of late Holocene sea-level change, these data are used to evaluate the suggestion that the apparent misfits between model predictions and geological reconstructions can be satisfactorily explained as a consequence of the lowering of sea-level index points by sediment compaction. The results indicate that a simple, first-order method of decompaction based on the stratigraphic position of sea-level index points, can eliminate much of the misfit between reconstructions and predictions, and substantially reduce vertical scatter in geological data. They also suggest that the influence of compaction on sea-level data from this region may be larger than previously thought. The simple addition of reliable stratigraphic data, in combination with targeted sampling, has the potential to improve our understanding of the compaction process, and increase the utility of existing data. This is increasingly important as the partnership between geophysical modelling and geological investigation becomes more commonplace in sea-level studies around the world. [ABSTRACT FROM AUTHOR]

On the basis of glacier and lake-level records, this paper attempts, for the first time, a comparison between high-resolution palaeohydrological and palaeoglaciological data in west-central Europe over the past 3500 years. A data set of tree-ring width, radiocarbon and archaeological data, in addition to historical sources, were used to reconstruct fluctuations of the Great Aletsch, the Gorner and the Lower Grindelwald glaciers in the Swiss Alps. The three ice-streams experienced nearly synchronous advances at c. 1000–600 BC and AD 500–600, 800–900; 1100–1200 and 1300–1860. These glacier fluctuations show strong correspondence with lake-level variations reconstructed in eastern France (Jura mountains and Pre-Alps) and on the Swiss Plateau. This supports the hypothesis of elimatically driven fluctuations. Historical date available for the period since AD 1550 reveal, in detail, various meteorological conditions behind the succesive glacier advances. Howere, in agreement with the general trend shown by the historical data, the synchroneity between glacier advances and periods of higher lake level suggests the impact of general winter cooling and an increase in summer moistur as responsible for reinforced feeding of both glaciers and lakes in west-central Europe ;over the past 3500 years. Finally, comparison between the Great Aletsech glacier and the residual 14C records supports the hypothesis that variations in solar activity were a major forcing factor of climatic oscillations in west-central Europe during the last Holocence. [ABSTRACT FROM AUTHOR]

Interactions between Holocene environmental changes and human subsistence strategies in semi-arid parts of eastern Africa are relatively poorly understood because of a paucity of sites where contemporaneous archaeological and palaeoenvironmental records are preserved. This paper presents new AMS 14C-dated palaeoenvironmental evidence of mid- to late-Holocene vegetation changes, in the form of pollen, charcoal, mineralogical and δ13Cbulk data, from a floodplain location on the Laikipia Plateau, Kenya, and in the context of information on modern plant–environment relationships, existing and new archaeological and historical data, and published palaeoclimatic records. Although relatively poorly resolved, the evidence indicates more wooded and relatively humid conditions compared with the present from before c. 6600 BP to c. 1900 BP. Evidence for vegetation changes over the last two millennia is more finely resolved and indicates increased burning and the expansion of fire-modified Acacia bushland c. 1900 BP and grassland c. 1700 BP. Burning to improve and extend pasture, and possibly to eradicate disease-prone habitats, may have been facilitated by prolonged periods of moisture deficits that might also have facilitated the spread of food production technologies. Vegetation changes c. 700 BP are associated with evidence for the occurrence of fires locally and could represent the activities of people and their animals close to the study site. [ABSTRACT FROM AUTHOR]

The focus of this paper is on the reconstruction of the mid-Holocene climatic changes based on the pollen records contained in a 6.2 m thick section in the southern part of the Tengger Desert, northwestern China. To understand the modern analogues of the mid-Holocene changes, modern pollen spectra across different vegetation zones from the Qilian Mountains to the lowland Tengger Desert were studied first. Four pollen combinations were identified, corresponding to four different modern ecological environments: (1) a Picea-Artemisia combination in a spruce forest and its vicinity; (2) an Artemisia-Chenopodiaceae-Gramineae-Salix combination in a mixture belt of montane grassland and poplar woodland; (3) a Chenopodiaceae-Artemisia-Nitraria combination in a desert steppe belt; and (4) an Elaeagnus-Artemisia-Chenopodiaceae-Nitraria combination in a desert riparian forest. Our study also shows that a relatively low percentage of Picea pollen (30–10%) seems to be associated with water transportation (alluvial deposits) and a very low percentage of Picea pollen (10–5%) appears to be related to long-distance air transportation. With references to the modern relationships between pollen assemblages and associated bioclimates, the pollen sequence covering the period between 8500 and 3000 cal. BP was used to infer the climatic change history. The results show that a warmer and drier climate dominated between 8500 and 7950 cal. BP. Subsequent decreases in Artemisia and warm desert forbs/shrubs taxa and contemporaneous fluctuating increases in montane coniferous and aquatics elements from 7950 to 7400 cal. BP reflect a fluctuating increase in humidity and/or a fluctuating decrease in temperature. The following period from 7400 to 5650 cal. BP was generally warm with the Holocene Climate Optimum occurring between 7400 and 6500 cal. BP. A remarkably cool spell followed between 6500 and 6300 cal. BP that was then succeeded by a warmer and more humid period between 6300 and 5650 cal. BP. The period between 5650 and 4450 cal. BP was characterized by drastic oscillations in climatic conditions with three humid and probably cold spells intervened by three relatively dry and warm spells. The period between 4450 and 3500 cal. BP was cold and humid, followed by a wet spell as indicated by a very high percentage of Typha pollen. [ABSTRACT FROM AUTHOR]

This paper examines the mid- to late-Holocene (c. 6850-1160 cal. yr BP) environmental history of Sierra de Gádor in southern Spain. The local vegetation dynamics are reconstructed through the palaeoecological record obtained from a lacustrine deposit situated at 1530 m. Various hypotheses are considered to explain the vegetation dynamics apparent in the palaeoecological evidence, including climatic change, fire occurrence and human activity. Although the vegetation in this region is sensitive to climatic change, threshold events driven by ecological factors are also apparent. Climatic events include a thermo-mesophytic optimum with abundance of deciduous trees and maximum lake water level found from c. 6850 to 5500 cal. yr BP. In contrast, changes in the frequency of major fire episodes appear to have shaped interspecific relationships and vegetation change, especially from c. 4200 cal. yr BP onwards. Biotic properties of the ecosystem such as the inertia of established tree populations, interconnected with competition adjustments, appear also to have played a role. Over the last two millennia, overgrazing, combined with natural and/or human-set fires, appears to have pushed mountain forests over a threshold leading to the spread of grassland, thorny scrub, junipers and nitrophilous communities. [ABSTRACT FROM AUTHOR]

Mediterranean ecosystems contain some of the highest levels of plant diversity of any region on Earth and are amongst those believed to be most at risk from the consequences of global warming. Yet such ecosystems are not static and have responded to environmental changes at a variety of scales and from a variety of causes, particularly climatic and anthropogenic. The purpose of this paper is to review recent research on environmental change and ecosystem response. Long-term records are available to analyse changes over glacial-interglacial cycles, while high resolution records show the sensitivity and coupling of Mediterranean, North Atlantic and Greenland records. For the Holocene, there is continued debate about the relative impact of anthropogenic activity, but there is also increasing recognition that mediterraneantype ecosystems should not be regarded as fragile, degraded landscapes, but are disturbanceadapted. Nevertheless, conservation measures face increasing challenges from contemporary climate change and human pressures. Some insights into the identification of refugial areas, either in glacial times or for present-day conservation purposes, come from molecular biogeographical studies of past faunal and floral distribution. [ABSTRACT FROM AUTHOR]

This paper reviews the development of the current 'supra-long' pine chronology for northern Finnish Lapland. In the forest-tundra ecotone region of northern Finnish Lapland over 250 samples from living Scots pines (Pinus sylvestris L.) and over 1700 samples of subfossil pines have been collected for dendrochronological studies. In addition, over 1400 subfossils have been sampled from the forested area of Finnish Lapland. The goal of the research was to build a more than 7000-year long continuous pine ring-width chronology. The construction of the chronology is now completed. The intensive phase of the data collection and chronology building lasted about 10 years, 1989 to 1999. The major part of the Finnish Lapland master curve was constructed several years ago, but it was extremely difficult to bridge the c. 300-year gap, prior to 165 BC between the 'absolute' younger part of the chronology and the 'floating' older part. The crucial samples were identified and assembled in the chronology in early 1999, and there is now an unbroken pine chronology about 7500 years long constructed from the subfossil forest-limit pines of northern Finnish Lapland. The severe growth depression centred on 330 BC is likely to have been caused by increased wetness. A brief summary is presented of inferred tree-line changes from the location of the samples. [ABSTRACT FROM AUTHOR]

This editorial introduces a special issue of The Holocene containing 12 papers which represent highlights from a European Commission research project: 'Analysis of Dendrochronological Variability and Associated Natural Climates in Eurasia - the last 10000 years' (ADVANCE-10K). The focus is on the climatic implications of dendrochronology and especially on developing an integrated, dendrochronological approach to high-resolution climatic reconstruction in the Holocene, with the ultimate aim of extending this to the global scale. Emphasis is given to: (1) long chronologies from northern Fennoscandia (pine), temperate central and western Europe (oak) and Siberia (larch); (2) the precise climatic signals reflected in these chronologies and possible links to atmospheric circulation patterns; (3) complementary methodologies for extracting climatic information from subfossil trees in a variety of different environmental settings; and (4) the use of a large (subhemispheric) network of tree-ring density data to examine detailed, geographical patterns in climatic variability at a high temporal resolution. These studies are placed in their wider context and future directions for research in this field are also highlighted. [ABSTRACT FROM AUTHOR]

Speleothems (cave dripstones) are formed as a part of the meteoric water cycle and therefore vari-ations in their growth rate and composition reflect environmental changes on the land surface above the cave. Since they are continental deposits, and possess a remarkably accurate dating potential, using TIMS U-series techniques, speleothems are important palaeoclimatic archives for the terrestrial environment, complementing the marine and ice-core records. The climatic proxies that can be deciphered from speleothems are growth rate, stable isotope composition (δ[sup 18]O, δ[sup 13] C), organic (humic) matter and trace element composition, as well as luminescent laminae, which may display annual rhythms. The nine papers in this special issue of The Holocene present the latest results in palaeoclimatic analysis from speleothems. [ABSTRACT FROM AUTHOR]

In a comment on the paper by Sundqvist et al. (2007a), Hammarlund and Edwards suggest that the oxygen isotope signal of the speleothem records K1 and L4 from northwestern Sweden as well as for the earlier published stalagmite SG93 from northern Norway should mainly reflect variation in the δ18O of mean annual precipitation. The main argument used by the authors is that the SG93 dδ18O record should show remarkable similarities with the lacustrine carbonate dδ18O record from Lake Tibetanus. The similarities between SG93 and Lake Tibetanus are mainly seen for the period between 10 and 9 ka BP, which is a period where both records have higher dδ18O values compared with later in the Holocene. If true, this would indicate that temperatures in northern Scandinavia would have reached their Holocene maximum between 10 and 9 ka BP, which is contrary to what has been reported from other archives in the region which place the Holocene climatic optimum somewhere between 8 and 5 ka BP. Several factors affect the dδ18O of speleothems and definitely also by annual mean dδ18O of the local precipitation. However, for Holocene speleothems from northern Scandinavia as well as from the Alps this signal seems to be overridden by other factors, such as variable mixing of summer and winter precipitation of cave drip water as well as the temperature-dependent fractionation between calcite and water. But the relative importance of the factors can differ between different timescales, caves and even speleothems from the same cave, depending on hydrological pathways. To better understand the factors controlling the stable oxygen isotopes in precipitation and proxy archives back in time there is a need for more highly resolved records as well as for more atmospheric and hydrological modelling. [ABSTRACT FROM AUTHOR]