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This paper introduces a series of articles assembled in a special issue that explore Holocene climate evolution, as recorded in lakes on the Island of Amsterdamoya on the westernmost fringe of the Arctic Svalbard archipelago. Due to its location near the interface of oceanic and atmospheric systems sourced from Arctic and Atlantic regions, Amsterdamoya is a key site for recording the terrestrial response to marine and atmospheric changes. We employed multi-proxy approaches on lake sediments, integrating physical, biogeochemical, and isotopic analyses to infer past changes in temperature, precipitation, and glacier activity. The results comprise a series of quantitative Holocene-length paleoclimate reconstructions that reveal different aspects of past climate change. Each of the four papers addresses various facets of the Holocene climate history of north-western Svalbard, including a reconstruction of the Annabreen glacier based on the sedimentology of the distal glacier-fed lake Gjoavatnet, a reconstruction of changing hydrologic conditions based on sedimentology and stratigraphy in Lake Hakluytvatnet, reconstruction of summer temperature based on alkenone paleothermometry from lakes Hakluytvatnet and Hajeren, and a hydrogen isotope-based hydrological reconstruction from lake Hakluytvatnet. We also present high-resolution paleomagnetic secular variation data from the same lake, which document important regional magnetic field variations and demonstrate the potential for use in synchronizing Holocene sedimentary records in the Arctic. The paleoclimate picture that emerges is one of early Holocene warmth from ca. 10.5 ka BP interrupted by transient cooling ca. 10-8ka BP, and followed by cooling that mostly manifested as two stepwise events ca. 7 and 4 ka BP. The past 4ka were characterized by dynamic glaciers and summer temperature fluctuations decoupled from the declining summer insolation.

This paper examines the evidence for climatic changes in the Eastern Mediterranean for the period 200–800 AD and offers hypotheses on the role of climatic fluctuations in the societal developments that occurred in this region at the end of Antiquity. The geographical focus of the paper includes Anatolia and the Levant, two major regions of the Eastern Roman Empire that are rich in environmental, historical and archaeological data. The paper starts with the review of current research on the economic, settlement and vegetation history of the Eastern Mediterranean in Late Antiquity, which provides the necessary framework for the study of potential climate impacts. The core of the article is devoted to the analysis of the palaeoclimatic evidence, which is divided in two groups. The first one encompasses the direct evidence, that is palaeoclimate proxies and the textual record of extreme weather events, while the second includes indirect information on climate, in particular multi-proxy studies that include pollen analysis, archaeological evidence, and the historical evidence of subsistence crises. We conclude that during our study period there occurred three periods of substantially different climatic conditions. A late Roman drought ∼350–470 AD was followed by a dramatic shift to much wetter climatic conditions. These in turn changed into increasing dryness after ∼730 AD in Anatolia and ∼670 AD in the Levant. The lack of chronological precision in the dating of the archaeological evidence and of some climatic records makes it impossible at present to make conclusive observations regarding the societal responses to these climatic fluctuations. Nonetheless in all probability, the extended and – in some areas - severe late Roman drought did not cause any major social upheaval or economic decline in Anatolia or the Levant, although it appears to have contributed to a change in patterns of water use in the cities. In contrast, the increased availability of moisture after ∼470 AD does appear to have contributed to the expansion of rural settlement and agriculture into environmentally marginal terrain, including semi-arid areas such as the Negev. In this way climate probably contributed to the general economic prosperity of the late Roman Empire in the east of the Mediterranean basin. The end of this late Roman world system came about finally in mid-7th c. and, at least in Anatolia, is not directly associated with any shift in climatic conditions. Aridity during early Medieval times may be one of the main factors behind the gradual long-term decline of settlement on the marginal lands in the Levant following Islamic conquest.

This paper provides a brief overview of the most common dating techniques applied in palaeoclimate and palaeoenvironmental studies including four radiometric and isotopic dating methods (radiocarbon, 230Th disequilibrium, luminescence, cosmogenic nuclides) and two incremental methods based on layer counting (ice layer, varves). For each method, concise background information about the fundamental principles and methodological approaches is provided. We concentrate on the time interval of focus for the INTIMATE (Integrating Ice core, MArine and TErrestrial records) community (60–8 ka). This dating guide addresses palaeoclimatologists who aim at interpretation of their often regional and local proxy time series in a wider spatial context and, therefore, have to rely on correlation with proxy records obtained from different archives from various regions. For this reason, we especially emphasise scientific approaches for harmonising chronologies for sophisticated and robust proxy data integration. In this respect, up-to-date age modelling techniques are presented as well as tools for linking records by age equivalence including tephrochronology, cosmogenic 10Be and palaeomagnetic variations. Finally, to avoid inadequate documentation of chronologies and assure reliable correlation of proxy time series, this paper provides recommendations for minimum standards of uncertainty and age datum reporting.

Fluctuations in glacier mass and volume are indicative of changes in the climate system. They also strongly affect regional climate and hydrology. In this paper, we explore possible relationships between the radial growth of Schrenk spruce (Picea schrenkiana Fisch. et Mey) and the mass balance of the Tsentralniy Tuyuksuyskiy (TS. Tuyuksuyskiy) Glacier, which is located on the northern slopes of the Tianshan Mountains in arid central Asia. We attempt to reconstruct the historical mass balance variability of the TS. Tuyuksuyskiy glacier using tree-ring widths and stable carbon isotope chronologies. The reconstruction is able to explain 62.1% of the variance in the annual glacier mass balance record over the 1965–2014 calibration period. We also analyzed centennial mass balance variability and its linkages to climate change. The TS.Tuyuksuyskiy glacier has a negative annual mass balance in most years and, since 1968, has undergone the most rapid and longest melting process in the past 166 years. The mass balance change of the glacier is controlled by the combination of temperature and precipitation conditions. This study could be useful for more detailed glaciological, hydrological, and climatological assessments in this portion of the Tianshan Mountains.

The Maloti-Drakensberg Mountains are southern Africa's highest and lie at a crucial interface between the sub-continent's drier, colder, more seasonal interior and its perennially productive sub-tropical coastal belt. Their location, high elevation, and topography make them ideal for exploring human responses to late Quaternary climatic change. This paper reviews and synthesizes palaeoclimatic and palaeoenvironmental data from the Maloti-Drakensberg region over the past 50,000 years. It then employs 325 calibrated radiocarbon dates to examine human occupational trends across the region and its component parts, discuss human-environment dynamics over this time-span, and explore patterning between particular phases of climatic change and the timing, mode, and motives of its exploitation by people. Key findings are that the region's Lesotho core may have served as a refugium for human populations during drier, more unstable climatic periods and that intensified exploitation of freshwater fish likely helped address resource stress in cooler ones. An agenda for future palaeoenvironmental and archaeological research is also mapped out.

This paper describes differences between Medieval Climate Anomaly (MCA) and present-day temperatures in the area composed of the Antarctic Peninsula, southern Patagonia, and the surrounding southern oceans. The investigation is conducted with the simulation results from the Community Earth System Model Last Millennium Ensemble (CESM-LME) considering the impact of each natural (volcanic activity and solar variability) and anthropogenic (greenhouse gas, ozone-aerosols and land use/land cover) individual forcing relative to the full forced simulations. Model results show generalized warming during the MCA in the study area. However, the simulated MCA temperatures are significantly colder than present-day mean values due to the influence of increased atmospheric greenhouse gas concentrations since the beginning of the modern Industrial Era in the ∼1850s. In fact, model runs in which only natural forcings were applied show that, in the absence of greenhouse gas forcing, present-day temperatures in the Antarctic Peninsula and southern Patagonia would be lower than or similar to those during the MCA. The study demonstrates the value of paleoclimate proxy–model comparisons but also highlights the limitations of current available proxy information to perform that integration in the study area.

Climate change is often cited as a major factor in social change. The so-called 8.2 ka event was one of the most pronounced and abrupt Holocene cold and arid events. The 9.2 ka event was similar, albeit of a smaller magnitude. Both events affected the Northern Hemisphere climate and caused cooling and aridification in Southwest Asia. Yet, the impacts of the 8.2 and 9.2 ka events on early farming communities in this region are not well understood. Current hypotheses for an effect of the 8.2 ka event vary from large-scale site abandonment and migration (including the Neolithisation of Europe) to continuation of occupation and local adaptation, while impacts of the 9.2 ka have not previously been systematically studied. In this paper, we present a thorough assessment of available, quality-checked radiocarbon (14C) dates for sites from Southwest Asia covering the time interval between 9500 and 7500 cal BP, which we interpret in combination with archaeological evidence. In this way, the synchronicity between changes observed in the archaeological record and the rapid climate events is tested. It is shown that there is no evidence for a simultaneous and widespread collapse, large-scale site abandonment, or migration at the time of the events. However, there are indications for local adaptation. We conclude that early farming communities were resilient to the abrupt, severe climate changes at 9250 and 8200 cal BP.

Changes in the strength and position of Southern Hemisphere westerly winds during the Last Glacial cycle have been invoked to explain both millennial and glacial–interglacial climate fluctuations. However, neither paleo models nor paleodata agree on the magnitude, or even the sign, of the change in wind strength and latitude during the most studied glacial period, the Last Glacial Maximum (LGM), compared to the recent past. This paper synthesizes paleo-environmental data that have been used to infer changes in LGM winds. Data compilations are provided for changes in terrestrial moisture, dust deposition, sea surface temperatures and ocean fronts, and ocean productivity, and existing data on Southern Hemisphere ocean circulation changes during the LGM are summarized. We find that any hypothesis of LGM wind and climate change needs to provide a plausible explanation for increased moisture on the west coast of continents, cooler temperatures and higher productivity in the Subantarctic Zone, and reductions in Agulhas leakage around southern Africa. Our comparison suggests that an overall strengthening, an equatorward displacement, or no change at all in winds could all be interpreted as consistent with observations. If a single cause related to the southern westerlies is sought for all the evidence presented, then an equatorward displacement or strengthening of the winds would be consistent with the largest proportion of the observations. However, other processes, such as weakening or poleward shifts in winds, a weakened hydrological cycle, extended sea-ice cover, and changed buoyancy fluxes, cannot be ruled out as potential explanations of observed changes in moisture, surface temperature, and productivity. We contend that resolving the position and strength of westerly winds during the LGM remains elusive based on data reconstructions alone. However, we believe that these data reconstructions of environmental conditions can be used in conjunction with model simulations to identify which processes best represent westerly wind conditions during the LGM.

This paper presents results from the first 1100 years of a long stable carbon isotope chronology currently in development from Scots Pine (Pinus sylvestris L.) trees growing in the Tornetrask region of northern Sweden. The isotope record currently comprises a total of 74 trees with a mean annual replication of >12, thereby enabling it to be compared directly with other tree-ring based palaeoclimate reconstructions from this region. In developing the reconstruction, several key topics in isotope dendroclimatology (chronology construction, replication, CO2 adjustment and age trends) were addressed. The resulting carbon isotope series is calibrated against instrumental data from the closest meteorological station at Abisko (AD1913-2008) to provide a record of June August sunshine for northern Fennoscandia. This parameter is closely linked to the direct control of assimilation rate; Photosynthetically Active Radiation (PAR) and the indirect measures; mean July August temperature and percent cloud cover. The coupled response of summer sunshine and temperature in this region permits a multiparameter comparison with a local reconstruction of past temperature variability based upon tree growth proxies to explore the stability of this coupling through time. Several periods are identified where the temperature (X-ray density) and sunshine (stable carbon isotope ratio) records diverge. The most significant and sustained of these occur between c AD1200-1380 and c AD1550-1780, providing evidence for a cool, sunny, two-phase Little Ice Age. Whilst summer sunshine reconstructed for the 20th century is significantly different from the mean of the last 1100 years (P 0.01), so it is the 17th-18th, and to a lesser extent, the 13th centuries rather than the early medival period that appear anomalous when viewed within the context of the last 1100 years. The observed departures between temperature and sunshine are interpreted as indicating a change in large-scale circulation associated with a southward migration of the Polar Front. Such a change, affecting the Northern Annular Mode (Arctic Oscillation) would result in more stable anticyclonic conditions (cool, bright, summers) over northern Fennoscandia, thus providing a testable mechanism for the development of a multi-phase, time-transgressive Little Ice Age across Europe.

There is a great deal of controversy regarding the fate of glaciers and ice fields on the Tibetan Plateau in the face of continued anthropogenic global warming. Paleoclimate reconstructions and spatial analyses aimed at mapping past climate changes are the key to understanding the climatic response of the Tibetan Plateau to changing conditions. Specifically, the numerous lakes distributed across the Tibetan Plateau can provide high-resolution (spatial and temporal) climate reconstructions to investigate past changes in the climate system. In this paper, we review the primary limitation to exploiting these valuable paleoclimate archives: errors in radiocarbon-based age models. We review the techniques that have been used to estimate 14 C reservoir ages on the Tibetan Plateau and compile the published 14 C reservoir ages to examine their spatial and temporal patterns and to assess the imposed chronological uncertainties. Using site-specific evaluations of Bangong Co and Lake Qinghai, we demonstrate that 14 C age model uncertainties permit equally probable and contrasting interpretations of existing paleoclimate records. We also examine 14 C-induced uncertainties in the spatial climatic response on the Tibetan Plateau to (1) the termination of the Last Glacial Maximum and (2) the Holocene Thermal Maximum. We conclude with recommendations for reducing uncertainties in future lake-based paleoclimate studies on the Tibetan Plateau.

The dispersal of the genus Homo occurred against a background of continuous environmental change. Here, dispersals of large mammals through the Levantine Corridor and into Western Europe and Java are studied and compared to existing records of climatic change and dispersals of early humans and lithic industry. The first human dispersal (with Oldowan lithic industry) out of Africa, around or shortly before 1.8 Ma may have been triggered by biological evolution and increased social organisation, rather than environmental change. After that event, increasing aridity led to decreased faunal exchange between Africa and Eurasia and may have isolated the human populations of Africa and Africa. Southern (Java) and Eastern Asia (China) also seem to have been isolated. Human dispersal into Western Europe may have been limited by closed environments in Central Europe until about 1.2 Ma ago, when faunal dispersal into Europe suggests the cyclic spread of open environments to the west. Acheulean technology originated in Africa, some 1.6-1.5 Ma ago, but its dispersal into Eurasia may have been obstructed by an arid Southwest Asia, until broadly about 0.9 Ma ago, when faunal exchange suggests that the area became temporarily less dry. By 0.6-0.5 Ma ago it reached Europe. © 2010 Elsevier Ltd., This paper benefited from discussions with members of the Atapuerca team and many others, particularly John de Vos. The results on biogeography presented here are a contribution to projects BOS2003-08938-C03-02 and CGL2008-03881 of the Ministerio de Ciencia y Inovación and NL-TAF-4053 of Synthesys.

This paper describes recent exceptional slope failures in high-mountain, glacial environments: the 2002 Kolka–Karmadon rock–ice avalanche in the Caucasus, a series of ice–rock avalanches on Iliamna Volcano, Alaska, the 2005 Mt. Steller rock–ice avalanche in Alaska, and ice and rock avalanches at Monte Rosa, Italy in 2005 and 2007. Deposit volumes range from 10 6 to 10 8 m 3 and include rock, ice and snow. Here we focus on thermal aspects of these failures reflecting the involvement of glacier ice and permafrost at all sites, suggesting that thermal perturbations likely contributed to the slope failures. We use surface and troposphere air temperatures, near-surface rock temperatures, satellite thermal data, and recent 2D and 3D thermal modeling studies to document thermal conditions at the landslide sites. We distinguish between thermal perturbations of volcanic-geothermal and climatic origin, and thermal perturbations related to glacier–permafrost interaction. The data and analysis support the view that recent, current and future climatic change increases the likelihood of large slope failures in steep glacierized and permafrost terrain. However, some important aspects of these settings such as the geology and tectonic environment remain poorly understood, making the identification of future sites of large slope instabilities difficult. In view of the potentially large natural disasters that can be caused by such slope failures, improved data and understanding are needed.

Long-term sedimentary sequences provide a wealth of useful information for research into the palaeo-environment, especially in relation to past climate change. Shorter records provide similar information in many archaeological contexts. However if such records are to be used to provide precise timing of events, and more critically the relative timing between different records, methods are needed to provide accurate and precise age–depth models for these sequences. Given the imprecision of individual calibrated radiocarbon determinations it is necessary to use the information we have about the deposition process to refine our chronologies and also to provide interpolation between dated levels in any sequence. Even with layer counted chronologies, the uncertainties are sometimes hard to quantify. This paper outlines a range of Bayesian models for deposition which have been implemented in the computer programme OxCal. These models can be used to combine information from the sediments themselves with radiocarbon or other direct dating information. Such models have the potential to integrate information between different records and provide a coherent chronology on which to base environmental or archaeological research.

This paper reviews the methodological and practical issues relevant to the ways in which natural scientists, historians and archaeologists may collaborate in the study of past climatic changes in the Mediterranean basin. We begin by discussing the methodologies of these three disciplines in the context of the consilience debate, that is, attempts to unify different research methodologies that address similar problems. We demonstrate that there are a number of similarities in the fundamental methodology between history, archaeology, and the natural sciences that deal with the past (“palaeoenvironmental sciences”), due to their common interest in studying societal and environmental phenomena that no longer exist. The three research traditions, for instance, employ specific narrative structures as a means of communicating research results. We thus present and compare the narratives characteristic of each discipline; in order to engage in fruitful interdisciplinary exchange, we must first understand how each deals with the societal impacts of climatic change. In the second part of the paper, we focus our discussion on the four major practical issues that hinder communication between the three disciplines. These include terminological misunderstandings, problems relevant to project design, divergences in publication cultures, and differing views on the impact of research. Among other recommendations, we suggest that scholars from the three disciplines should aim to create a joint publication culture, which should also appeal to a wider public, both inside and outside of academia.

19 pages, 9 figures.-- Printed version published Jun 2006., Climatic change has often been cited as a determining factor in cultural changes in the context of the Harappan Civilisation of northwestern South Asia, 2500–1900 BC. While these claims have been criticized by archaeologists they continue to be accepted by non-archaeologists, including Quaternary scientists. The purpose of this paper is to assess the available evidence and published arguments and to provide a constructive working synthesis of evidence for the palaeoenvironmental setting of northwestern South Asia for the mid- to late Holocene, especially ca 4000–1000 cal BC, and its possible connection to important cultural changes. We conclude that Harappan urbanism emerged on the face of a prolonged trend towards declining rainfall. No climatic event can be blamed for a precipitous end of this civilisation, although strategic local shifts in agriculture that may have begun in response to prolonged droughts at ca 2200 BC may have contributed to the de-urbanisation process and the restructuring of human communities over the following 200–300 yr.

This paper presents a new correlation of Late and Middle Pleistocene fluvial sedimentary sequences in Greek, Libyan and Spanish river basins and evaluates river response to climate change over the Last Interglacial-Glacial Cycle. Over the past 200,000 years there have been at least 13 major alluviation episodes in the Mediterranean, although the amplitude, frequency and possibly, duration of these events varied significantly across the region. Parts of Oxygen Isotope Stage (OIS) 5 appears to have been periods of pronounced landscape change in many Mediterranean catchments with major river aggradation occurring at ∼109-111 ka (during OIS 5d) and most notably at ∼88 ka (OIS 5b/5a boundary). Other parts of OIS 5 appear to have been periods of relative fluvial inactivity. OIS 2 and 3 were both characterised by an apparent increase in the number of alluviation events, and this record of river behaviour parallels many other palaeoenvironmental records in the region which also show more frequent climate fluctuations between ∼12 and 65 ka. There is evidence for a high degree of synchrony in major river aggradation events across the Mediterranean in catchments with very different sizes, tectonic regimes and histories. Climate-related changes in catchment hydrology and vegetation cover over the last 200 ka would appear to be the primary control of large-scale (catchment wide) sedimentation over time periods of between 103 and 104 years. © 2002 Elsevier Science Ltd. All rights reserved.

Continuous, high-resolution δ18O records from cored sediments of Pyramid Lake, Nevada, indicate that oscillations in the hydrologic balance occurred, on average, about every 150 years (yr) during the past 7630 calendar years (cal yr). The records are not stationary; during the past 2740 yr, drought durations ranged from 20 to 100 yr and intervals between droughts ranged from 80 to 230 yr. Comparison of tree-ring-based reconstructions of climate change for the past 1200 yr from the Sierra Nevada and the El Malpais region of northwest New Mexico indicates that severe droughts associated with Anasazi withdrawal from Chaco Canyon at 820 cal yr BP (calendar years before present) and final abandonment of Chaco Canyon, Mesa Verde, and the Kayenta area at 650 cal yr BP may have impacted much of the western United States.During the middle Holocene (informally defined in this paper as extending from 8000 to 3000 cal yr BP), magnetic susceptibility values of sediments deposited in Pyramid Lake's deep basin were much larger than late–Holocene (3000–0 cal yr BP) values, indicating the presence of a shallow lake. In addition, the mean δ18O value of CaCO3 precipitated between 6500 and 3430 cal yr BP was 1.6‰ less than the mean value of CaCO3 precipitated after 2740 cal yr BP. Numerical calculations indicate that the shift in the δ18O baseline probably resulted from a transition to a wetter (>30%) and cooler (3–5°C) climate. The existence of a relatively dry and warm middle-Holocene climate in the Truckee River–Pyramid Lake system is generally consistent with archeological, sedimentological, chemical, physical, and biological records from various sites within the Great Basin of the western United States. Two high-resolution Holocene-climate records are now available from the Pyramid and Owens lake basins which suggest that the Holocene was characterized by five climatic intervals. TIC and δ18O records from Owens Lake indicate that the first interval in the early Holocene (11,600–10,000 cal yr BP) was characterized by a drying trend that was interrupted by a brief (200 yr) wet oscillation centered at 10,300 cal yr BP. This was followed by a second early-Holocene interval (10,000–8000 cal yr BP) during which relatively wet conditions prevailed. During the early part of the middle Holocene (8000–6500 cal yr BP), high-amplitude oscillations in TIC in Owens Lake and δ18O in Pyramid Lake indicate the presence of shallow lakes in both basins. During the latter part of the middle Holocene (6500–3800 cal yr BP), drought conditions dominated, Owens Lake desiccated, and Lake Tahoe ceased spilling to the Truckee River, causing Pyramid Lake to decline. At the beginning of the late Holocene (∼3000 cal yr BP), Lake Tahoe rose to its sill level and Pyramid Lake increased in volume.

The study of Quaternary environmental change is directly applicable to on-going issues of global conservation. Palaeoecological research techniques provide the tools to address some of the key questions presently being asked by conservation ecologists and land management organizations. But is this type of analysis currently being utilized to its full potential? Are the results of palaeoenvironmental analyses routinely applied to practical issues of natural resource management, and if not what can be done to expand the application of this research within the conservation community? This paper reviews recent developments in the application of the analysis of late Quaternary environmental change to key environmental issues of biodiversity and conservation management and examines areas which could be strengthened in the future including: (i) determination of baselines and natural ecosystem variability; (ii) understanding ecological thresholds and resilience; (iii) climate change conservation strategies; (iv) biological invasions; and (v) conservation and culture. © 2008 Elsevier Ltd. All rights reserved.