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The use of archaeological proxy records representative of population dynamics is paramount for a richer understanding of prehistoric cultural change, but its use require a dialectic assessment between proximate climatic drivers and ultimate cultural responses. Focusing on the Stone Age archaeological record of Western Norway (11,500–4300 cal. BP), this paper presents an exhaustive empirical curation and statistical testing between changing climates and demographic responses among coastal hunter-fisher-gatherers. The results connect long-term demographic fluctuations with changes in annual mean temperatures and seasonality and the results are discussed in relation changes in technology, subsistence and mobility. The paper also highlights the process of population decline and cultural loss towards the end of the Late Mesolithic (ca. 7000–6000 cal. BP) and emerging cultural novelties and population re-growth during the Early and Middle Neolithic (ca. 6000–4300 cal. BP). However, despite its strong correlation, the archaeological record of Western Norway lacks sufficient detail to ascribe an exclusive explanatory role to climate change, especially in episodes of significant population decline. This helps to emphasise that changing climates, while evidently central, form but a part of a larger system of interactions leading to demographic fluctuations and cultural change, the substantiation of which requires significant empirical improvements to the archaeological record. [ABSTRACT FROM AUTHOR]

Glaciers and ice caps in Norway are presently undergoing mass loss, areal reduction, and frontal retreat, mainly a result of increased summer ablation due to rising summer temperatures over Scandinavia, especially after 2000 CE. In this paper, the glacier mass-balance response of 10 Norwegian glaciers with continuous mass balance observations (>10 years) to climate projections from 1971–2000 to 2071–2100 have been estimated. Projected changes in mean summer temperature and mean winter precipitation from 1971–2000 to 2071–2100, applying the RCP8.5 emission scenario for five different regions in Norway; 'Sogn og Fjordane' and 'Hordaland', now Vestland County in western Norway, 'Oppland', now part of Innlandet County in eastern Norway, and Nordland County and Finnmark County, both in Northern Norway), range between +3.5°C and +5.0°C, and between +5% and +25%, respectively. These climate projections have been converted (by linear regression with overlapping observational mass-balance data) into specific surface glacier mass balance [winter balance (B w), summer balance (B s), and annual balance (B a) for 10 glaciers in Norway with mass-balance series [Ålfotbreen, Nigardsbreen (part of Jostedalsbreen), Austdalsbreen (part of Jostedalsbreen), Rembesdalskåka (part of Hardangerjøkulen), Blomstølskardsbreen (part of Søre Folgefonna), Storbrean, Hellstugubrean, Gråsubrean, Engabreen (part of Vestre Svartisen, Langfjordjøkelen (data: http://glacier.nve.no/glacier/viewer/ci/no/) yielding a total, cumulative surface glacier mass loss from 2000 to 2100 CE in the range of -85.2 ± 4 to -197.3 ± 10 m water equivalents. The estimated changes in equilibrium-line altitudes (ELAs), in the range of 230 ± 10 to 630 ± 30 m, indicate that the mean ELA may reach the upper part of 7 of the 10 glaciers included in this study [Ålfotbreen, Austdalsbreen, Rembesdalskåka, Blomstølskardsbreen, Gråsubrean, Engabreen and Langfjordjøkelen] by the end of the 21st century. The projected glacier mass loss and ELA rise, and thus changes in glacier length, area and volume, will most likely have profound consequences for future glacier hydrology (runoff), hydropower production, wildlife, ecosystems, glacier hazards, and tourism. [ABSTRACT FROM AUTHOR]

Charcoal from archaeological contexts differs from off-site pollen samples as it is mainly a product of intentional human action. As such, analysis of charcoal from excavations is a valuable addition to studies of past vegetation and the interaction between humans and the environment. In this paper, we use a dataset consisting of 6186 dated tree species samples from 1239 archaeological sites as a proxy to explore parts of the Holocene forest development and human-vegetation dynamics in South-Eastern Norway. From the middle of the Late Neolithic (from c. 2000 BC) throughout the Early Iron Age (to c. AD 550) the region's agriculture is characterized by fields, pastures and fallow. Based on our data, we argue that these practices, combined with forest management, clearly altered the natural distribution of trees and favoured some species of broadleaved trees. The past distribution of hazel (Corylus avellana) is an example of human impact on the vegetation. Today, hazel is not even among the 15 most common tree species, while it is one of the most prevalent species in the archaeological record before AD 550. The data indicate that this species was favoured already by the region's Mesolithic hunter-fisher-gatherers, and that it was among the species that thrived extremely well in the early farming landscape. Secondly, our analysis also indicates that spruce (Picea abies) first formed large stands in the south-eastern parts of Norway c. 500 BC, centuries earlier than previously assumed. It is argued that this event, and a further westward expansion of spruce, was partly a consequence of a specific historical event – the first millennium BC farming expansion. [ABSTRACT FROM AUTHOR]

The influence of the 'Little Ice Age' (LIA) on the glaciers of Svalbard has been well documented for a long time. This paper presents new data on the LIA maximum glacier extent and retreat by aerial photo interpretation and Geographic Information Systems (GIS) tools. We also make cartography where all results are shown in greater detail. During the LIA maximum, we find that the glacier area of Svalbard was 38,871 km2, and since then, the total glacier area loss in the archipelago has been 5096 km2 (13.1%). The total current glaciated area from the late 2000s is 33,775 km2. Since the LIA, the glaciers in the main islands of the archipelago have retreated by 12.8% in Spitsbergen, 13.4% in Nordaustlandet, and 16.7% in Barentsøya and Edgeøya. The analysis of the LIA maximum glacier extent in the different major drainage basins shows important differences; about 100 years ago, some glacier basins were more than 19% larger in the western and central regions of Spitsbergen, or even more than 23% larger in southern Nordaustlandet, while other small basins found in the northeast of this island were barely 1% larger. The greatest retreats are found in the tidewater glaciers, more variable and responsive to the water temperature changes, water dynamics, and bathymetry. In addition, the advances at some of these glaciers may correspond with surges, which means that the rapid retreats are caused by the post-surging phases as well as climate. The conclusions of this research point out an important ice loss in all of Svalbard since the LIA and the high vulnerability of this Arctic archipelago to global warming. [ABSTRACT FROM AUTHOR]

Over the recent decades, glaciers have in general continued to lose mass, causing surface lowering, volume reduction and frontal retreat, thus contributing to global sea-level rise. When making assessments of present and future sea-level change and management of water resources in glaciated catchments, precise estimates of glacier volume are important. The glacier volume cannot be measured on every single glacier. Therefore, the global glacier volume must be estimated from models or scaling approaches. Volume–area scaling is mostly applied for estimating volumes of glaciers and ice caps on a regional and global scale by using a statistical–theoretical relationship between glacier volume (V) and area (A) (V = cAγ) (for explanation of the parameters c and γ, see Eq. 1). In this paper, a two-dimensional (2D) glacier model has been applied on four Norwegian ice caps (Hardangerjøkulen, Nordre Folgefonna, Spørteggbreen and Vestre Svartisen) in order to obtain values for the volume–area relationship on ice caps. The curve obtained for valley glaciers gives the best fit to the smallest plateau glaciers when c = 0.027 km3−2γ and γ = 1.375, and a slightly poorer fit when the glacier increases in size. For ice caps, c = 0.056 km3−2γ and γ = 1.25 fit reasonably well for the largest, but yield less fit to the smaller. [ABSTRACT FROM AUTHOR]

The topic of this paper is the importance of climate for the population and settlement in medieval and early modern times. Were the demographic crises caused by crop failure and famine or by disease? I begin by reviewing European research (particularly English) relating to the issue. The views of Norwegian historians regarding the causes of the agrarian crisis in the late Middle Ages are then examined. Hasund (Hasund S, 1919, 1944, Den store mannedauden. Or Noregs bondesoge. Glytt og granskingar II, Oslo, pp. 82–161. First printed in Beretning om Norges Landbrukshøiskoles virksomhet 1918–1919) claimed it was the plagues, not the climate, that held the population at a low level to the end of the Middle Ages, a view that has been repeated in recent years by such researchers as Lunden (Lunden K, 2002, Norges landbrukshistorie II, 1350–1814. Frå svartedauden til 17. mai. Oslo) and Moseng (Moseng OG, 2006, Den flyktige pesten. Vilkårene for epidemier i Norge i seinmiddelalder og tidlig nytid. Oslo). This paper claims that the role of the climate has been underestimated, in particular that the climatic shock of several bad years in a row directly and indirectly brought appreciable excess mortality in a country situated so far north. ‘Bad’ years demonstrated through dendrochronology are in many cases reflected in documentary evidence concerning poor corn harvests and high mortality. [ABSTRACT FROM PUBLISHER]

This paper presents the results of a study of surface pollen deposition on 26 glacier forelands in the Jostedalsbreen–Jotunheimen region of southern Norway. Numerical techniques, including two-way indicator species analysis (TWINSPAN), detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA), are used to identify distinct plant assemblages, to examine the pollen–vegetation relationship and to distinguish broad trends in the data. The source of pollen is fundamental; the majority of samples, especially those from sparsely vegetated sites, are dominated by arboreal pollen (up to 90% of the total land pollen (TLP) sum), most with a long-distance source. However, indicator taxa, notably Salix and Empetrum, although present at low frequencies, can hold the key to the true nature of the local vegetation. Indicator taxa produce strong correlations between their presence in the vegetation and representation in the pollen spectra, at times essential to distinguish plant communities. Multivariate analysis of the 197 surface pollen samples and vegetation data indicates the broad division of the sub-alpine and alpine vegetation into four major groups: pioneer communities, snowbed communities, heath communities and woodland. The primary DCA ordination axes show significant correlations with altitude and terrain age (e.g. correlation r = 0.36 between altitude and non-arboreal pollen (NAP) Axis-1). The most readily interpretable results are produced by CCA simultaneous ordination of vegetation data and NAP data. The potential for improving the interpretation of Holocene vegetation is assessed. [ABSTRACT FROM AUTHOR]

The human colonization of Norway occurred in the Pleistocene–Holocene transition – one of the most abrupt and severe climatic shifts in human history. For 1500 years (9500–8000 bc), the whole coast was occupied by mobile, marine-oriented hunter-gatherers. This paper explores dynamic relations between human adaptation and marine environmental variations in this period. An updated record of archaeological sites and palaeo-oceanographic data suggests a correlation between marine productivity and site distribution and density. The data further demonstrate spatial and temporal differences in the environment. A cooling pulse at 9300–9200 bc (the Preboreal Oscillation) with widespread ecological consequences must have been noticeable to humans occupying Norwegian landscapes. A more gradual shift occurred around 8800 bc when the arctic climate gave way to warmer conditions: The Norwegian Atlantic current stabilized, all fjord systems became ice-free, and animal diversity increased. In the northernmost region, the impact of Atlantic water was less severe, and Polar conditions with more sea ice seem to have lingered throughout the period. Variations in the site pattern may be related to these fluctuations in the resource situation. Variations in the lithic industry, on the other hand, seem to be connected to technological choices or local traditions, rather than environmental dissimilarities. The archaeological record indicates that the lifestyle, which developed under arctic conditions, was maintained through a flexible mobility pattern and a versatile tool technology, but the Norwegian coast also provided a good base to uphold such a lifestyle. [ABSTRACT FROM PUBLISHER]

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]

The steep outlet glaciers of Jostedalsbreen, western Norway, are good examples of sensitively reacting maritime mountain glaciers. Their changes in length, frontal position and lower tongue's morphology during the past 20 years have been well documented. At first they experienced a strong frontal advance. After AD 2000 glacier behaviour was dominated by a strong frontal retreat, in some cases causing a separation of the lowermost glacier tongue. In this paper, the glacier length changes are presented both visually and numerically, supplemented by mass balance and meteorological data. The glacier behaviour is interpreted and its causes are discussed. Whereas the factors controlling the advance during the 1990s seem clear, the interpretation of the most recent retreat still leaves some uncertainties. The actual glacier front behaviour cannot fully be related to the mass balance data. Terminus response times and relations between individual mass balance and meteorological parameters have changed. Some hypotheses are given, including disturbance of the 'normal' mass transfer and dynamical response of the glacier front because of excessive ablation on the lowermost glacier tongues and summer back melting. These findings underline the sensitivity of maritime glaciers to climate changes. The empirical findings need to be taken into account in the interpretation of recent glacier length changes and their future modelling. [ABSTRACT FROM AUTHOR]

This paper presents the results of simulated pollen counts from the central Scandes Mountains in Sweden which are used to examine the application of a pollen-based modelling approach to treeline fluctuations. Treelines are considered sensitive indicators of climate variability, and greater consideration of the palynological signal of treeline fluctuations is important in critical and rigorous use of pollen analysis to reconstruct variations in treelines. The approach presented here is to construct GIS-based models of the landscape (based on topographic and land cover attributes) onto which placement of different vegetation communities can represent changes in treelines in space (by adjusting the altitudinal positioning of treelines) and time (by using five time slices through the Holocene). The application of the POLLSCAPE model of pollen dispersal and deposition is then applied to generate simulated pollen counts for a large number (121) of sites placed across an altitudinal range in the simulated landscape. Comparison of simulated data to empirical pollen data from the region validates the approach through reasonable matching of the main trends in the pollen data sets. The success of the modelling approach is that it has helped to refine the process by which variations in fossil pollen assemblages are constructed, and also provides a tool by which the optimum sampling locations can be determined for treeline-focused work. [ABSTRACT FROM AUTHOR]

Ice cores from the relatively low-lying ice caps in Svalbard have not been widely exploited in climatic studies owing to uncertainties about the effect of meltwater percolation. However, results from two new Svalbard ice cores, at Lomonosovfonna and Austfonna, have shown that with careful site selection, high-resolution sampling and multiple chemical analyses it is possible to recover ice cores from which part of the annual signals are preserved, despite the considerable meltwater percolation. The new Svalbard ice cores are positioned in different parts of Svalbard and cover the past 800 years. In this paper we focus on the last 400 years. The δ18O signals from the cores are qualitatively similar over most of the twentieth century, suggesting that they record the same atmospheric signal. Prior to AD 1920, the Austfonna ice core exhibits more negative δ18O values than Lomonosovfonna, although there are intermittent decadal-scale periods throughout the record with similar values. We suggest that the differences reflect the effect of the inversion layer during the winter. The pattern in the δ18O records is similar to the Longyearbyen air-temperature record, but on an annual level the correlation is low. The Austfonna record correlates well with the temperature record from the more distant and southwesterly located Jan Mayen. A comparison of the ice-core and sea-ice records from this period suggests that sea-ice extent and Austfonna δ18O are related over the past 400 years. This may reflect the position of the storm tracks and their direct influence on the relatively low-altitude Austfonna. Lomonosovfonna may be less sensitive to such changes and primarily record free atmospheric changes instead of variations in sea-ice extent, the latter is probably a result of its higher elevation. [ABSTRACT FROM AUTHOR]

In the sedimentary record of the permanently anoxic Drammensfjord, a suite of lipid biomarkers that are derived from the alga Botryococcus braunii (Kützing), botryococcenes, is present in varying amounts, but absent in sediments deposited after AD 1850. The disappearance is concurrent with the industrialization of sawmills and the introduction of paper and pulp mills along the river Drammen and upstream water bodies, and the related increase of anthropogenic eutrophication. Because of the sensitivity of this alga for environmental change, a direct correlation between these two events is inferred. This implies that the disappearance of the botryococcenes can serve as a palaeoenvironmental indicator for early eutrophication or environmental change in general. This may be a useful tool in the ongoing research to unravel the response of natural systems to climatic, geophysical or anthropogenic changes. [ABSTRACT FROM AUTHOR]