Search

With the ever-increasing emphasis on climate change and sustainability, there is growing interest in using environmentally friendly coastal structures. In addition to engineering and cost factors, the construction global warming potential (GWP) can and should be an influencing factor in the selection and design of the structures. Therefore, knowledge of construction GWP facilitates informed decision-making in coastal projects to achieve climate goals. Considering the number of Icelandic-type berm breakwater (IceBB) structures worldwide, this structure's design method is commonly accepted in coastal protection projects. In this paper, the construction process of an IceBB was assessed for its GWP and compared with concrete armor unit protection of a conventional rubble mound breakwater (ConRMB). The assessment and comparison were made for constructing a breakwater to protect the port of Thorlakshofn in southwest Iceland. The life cycle assessment (LCA) methodology was applied to calculate the construction carbon footprint of the structures using GaBi software, version 10.6.1. Using the International Union for Conservation of Nature (IUCN) criteria for nature-based solutions (NBS) and based on the existing literature, the characteristics of IceBB were briefly explored. The results showed that the construction of IceBB has a lower GWP than ConRMB, mainly due to using natural rock armor instead of concrete armor units. Furthermore, the results indicated that IceBB characteristics meet the IUCN criteria for NBS and thus can be granted as a (hard) NBS coastal structure. Acknowledging the advantages of IceBB, adopting this structure in coastal protection projects could meaningfully contribute to climate change mitigating policies. [ABSTRACT FROM AUTHOR]

As the global climate is changing dramatically, the Westfjords of Iceland are facing a multitude of challenges, including changing weather patterns, sea level rise, and invasive species. In order to cope with the recent climatic changes—many of which present great uncertainties to livelihoods—strategies must be developed to plan and adapt for the future. Iceland has recently launched marine spatial planning (MSP) endeavours, and one of the first planning processes has been conducted in the Westfjords. MSP presents opportunities for authorities, stakeholders, and the public to come together to forge a sustainable path ahead for marine areas that are under increasing pressure from human activities. However, MSP comes with its own considerable challenges as it attempts to engage stakeholders and the general public in decisions about an 'invisible' space largely beneath the surface of the sea. In this paper, the uncertainties of the environmental changes will be explored in conjunction with the multitude of societal challenges to coastal and marine planning in the Westfjords to establish Iceland's unique context for MSP and to make recommendations for its development. Data from the planning documents as well as from semi-structured interviews and a workshop conducted in the Westfjords will be analysed and discussed. The results show both an urgent environmental need to take action to adapt to ongoing climate change effects and a complex societal structure that favours those who already have power and influence over others. Our recommendations include reforming the Icelandic MSP process with a view to strengthening the public participatory channels as well as the transparency, trust, and accessibility of the process. [ABSTRACT FROM AUTHOR]

Climate change is one of the most pressing issues of our time. Rising temperatures, changing precipitation and more weather extremes pose risks to local societies worldwide. Yet, climate change is most often presented and reported on a global or national scale. This paper aims to analyze the key aspects of climate change on the local scale by assessing temporal and spatial changes in temperature and precipitation in the Westfjords in north-western Iceland and evaluate their impacts on the region's livability. Existing temperature and precipitation data were used to model trends in climate change at an unprecedented resolution. The results show that the period of 2001–2020 was warmer than the 1961–1990 reference period in almost every month of every year, and that warming was more pronounced in the winter months. Furthermore, precipitation increased during 1991–2020 period compared to 1961–1990. These detected local patterns confirm some of the major predictions about climate change on the global scale. Considering the impact of climate change at the local level is critical, as it allows the community to envisage their future and provides better possibilities to mitigate, prepare for or adapt to the predicted changes. [ABSTRACT FROM AUTHOR]

The paper reports the results of reconstruction of the heliospheric modulation potential from radiocarbon data for the time interval from the mid-second millennium B.C. to the end of the first millennium A.D. It is known that significant climatic changes took place on the Earth during that time; specifically, the thickness of glaciers in Iceland and Norway were changing. Coincident changes are also observed in the radiocarbon data. The results of calculations show that the heliospheric modulation potential reaches a maximum (~590 MV) on this interval approximately in 1705 B.C. This suggests that solar activity at that moment was highest for the considered interval. Conversely, around 750 and 350 B.C., the smallest values of the modulation potential were observed and, consequently, solar activity could be lowest from the mid-second millennium B.C. to the end of the first millennium A.D. [ABSTRACT FROM AUTHOR]

The North Atlantic Oscillation (NAO), which manifests as an irregular atmospheric fluctuation, has a profound effect on the global climate change. The NAO index (NAOI) is the quantitative indicator that can reflect the intensity of the NAO events, and its traditional definition is the normalized sea level pressure (SLP) difference between Azores and Iceland. From the variation tendency of the NAOI, we found that it is difficult to predict the NAO with the characteristics of variability and complexity. As a data-driven approach, the deep neural network presents great potential in learning the mechanisms of climate forecasting. In this paper, we adopt long short-term memory (LSTM) and ConvLSTM to predict the NAO from two aspects, NAOI and SLP, respectively. In previous studies, LSTM has been regarded as a resultful method for time series prediction. ConvLSTM can capture both the temporal and spatial interdependencies of the SLP field; then, the NAOI can be calculated from the SLP output. In order to improve the prediction reliability, we utilize the discrete wavelet transform (DWT) as a preprocessing technique to decompose original data into different frequencies, considering the local time dependency. It can effectively preserve the features of high-frequency data and forecast extreme events more accurately. The proposed DWT-LSTM and DWT-ConvLSTM models are compared against multiple advanced models, such as LSTM, Holt-Winters, support vector regression (SVR), and gated recurrent unit (GRU). The results indicate that both DWT-LSTM and DWT-ConvLSTM perform better, particularly at peak values. As for the 31 NAO events from 2006 to 2015, our models achieve the lowest prediction error and the best stability. Compared with the forecast products of CPC named Global Forecast System (GFS) and the ensemble forecasts (ENSM), our models are much closer to observation in multistep forecasting. [ABSTRACT FROM AUTHOR]

Younger Dryas ice‐marginal ('hummocky') moraines in Scotland represent valuable terrestrial archives that can be used to obtain important information on ice‐marginal dynamics and glacier thermal regimes during a period of rapid climatic change. In this paper, we present detailed sedimentological studies of Younger Dryas ice‐marginal moraines in the Gaick, central Scotland, the former site of a spatially restricted plateau icefield. Exposures demonstrate that moraines in the Gaick represent terrestrial ice‐contact fans, with evidence of proglacial and subglacial glaciotectonization, as reported elsewhere in Scotland. The exposures also reveal the influence of local hydrogeological conditions, with pressurization of the groundwater system leading to the formation of hydrofracture fills within some moraines. Clast shape analysis shows that all the moraines contain debris consistent with transport in the subglacial traction zone. The sedimentological data, and the planform arrangement of the moraines as nested arcs or chevrons, indicate that retreat of the Younger Dryas Gaick Icefield outlets was incremental and oscillatory. This evidence strongly suggests a mainly temperate thermal regime and short glacier response times, but with narrow cold‐ice zones near the margins facilitating the elevation of basal debris to the glacier surface. Analogous glaciodynamic regimes occur at modern ice‐cap and plateau icefield outlets in Iceland and Norway, although there are significant differences in the nature of ice‐marginal deposition. The glaciodynamic signature recorded by moraines in the Gaick has allowed us to shed new light on the ice‐marginal dynamics and thermal regime of one of the most easterly Younger Dryas icefields in Scotland. [ABSTRACT FROM AUTHOR]

This paper attempts to provide an empirical application of the enhanced Regional Tourism Sustainable Adaptation Framework using a case study of Mombasa Kenya. Climate variability is a challenge to tourism destinations, especially coastal and Island destinations, categories under which Mombasa, our study site falls under. Mombasa has limited capacity to adapt to climate change considering its socio economic conditions and weak institutions, thus making it necessary to explore the possible sustainable pathways for the city using the enhanced Regional Tourism Sustainable Adaptation Framework. Earlier frameworks for tourism adaptation to climate change lacked focus on regional dynamics as well as sustainability aspects, and their implementation pose the risk of mal adaptation to some extent. Using secondary data and data from interviews with tourism stakeholders in Mombasa, the enhanced Regional Tourism Sustainable Adaptation Framework guides our assessment of vulnerability and resilience of the destination, as well as identification of region specific adaptation options for the city within the context of sustainable practice. Based on climate change perceived impacts, risks and vulnerability various adaptation options are presented and discussed as provided in literature. The usefulness of the framework in guiding regional tourism destination managers and policy makers in their pursuit for a regional adaptation options within the tourism sector in order to reduce destinations vulnerability, increase resilience and take advantage of opportunities presented by climate change is underscored. [ABSTRACT FROM AUTHOR]

This paper focuses on the Gap Rock lighthouse, a legendary maritime infrastructure built 130 years ago in the Chinese territory and an early example of joint venture among the Qing Dynasty, the British Empire and the Hong Kong Colonial Government over a course of two decades. Based on 4 years of cross-territorial archival and field research as well as in-depth interviews with descendants of two key stakeholders, the origin of this lasting legacy on the sea is traced, followed by a detailed account of its challenging processes of planning, design and construction, and of the considerable damage to the compound by a severe typhoon in 1893. A qualitative analysis of the key contributing factors of the damage was conducted by taking into consideration the Island's unique topography and the historical records of territorial weather reports. A re-construction of the typhoon impact on the Lighthouse is presented to explain the possible mistakes in its siting and design that eventually caused the severe damage. This serves as a reminder of the significance of a thorough geographical investigation for any infrastructure for all construction professionals in the face of climatic change. This article is part of the theme issue 'Environmental loading of heritage structures'. [ABSTRACT FROM AUTHOR]

Proglacial groundwater-fed features, such as seeps, substantially impact proglacial geomorphology, hydrology, and ecology. However, there is a paucity of research on the impacts of climate change and glacier retreat on the extent of these important features. This paper aims to investigate the impact of glacier retreat on proglacial groundwater levels and on the extent of groundwater-fed seeps. Research has taken place in western Skeiðarársandur, the large proglacial outwash plain of Skeiðarárjökull, a retreating temperate glacier in southeast Iceland. Changes in the extent of proglacial groundwater seeps were mapped using historical aerial photographs from 1986, 1997, and 2012. Proglacial groundwater levels were monitored in shallow boreholes between 2000 and 2012. The western margin of Skeiðarárjökull has retreated approximately 1 km beyond its position in 1986. However, this retreat was punctuated by short periods of readvance. The geomorphology and groundwater systems at the site were substantially impacted by the November 1996 jökulhlaup, whose deposits altered approximately 18% of the area of groundwater seeps. The surface areas of groundwater seeps and lakes in the study area have declined by ~97% between 1986 and 2012. Most of the decline took place after 1997, when the mean annual rate of retreat increased three-fold. Groundwater levels also declined substantially between 2000 and 2012, although this trend varies spatially. The paper provides a conceptual model of the controls on proglacial shallow groundwater systems. Direct impacts of glacier retreat are suggested as the main cause for the declines in proglacial groundwater levels and in the extent of groundwater seeps. These declines are expected to adversely impact sandur ecology. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Due to both the environmental impacts and the economic opportunities brought about by climate change, interest in the Arctic is rising in Asia. While there is a growing scholarship analyzing Asian interest in the Arctic, Iceland's reception to this interest has been under-studied. This paper explores Iceland's rising interest in the Arctic and its linked response to growing Chinese overtures toward Iceland and the region. Data were gathered from peer-reviewed literature, policy documents, popular media articles, participant observation at the Arctic Circle conference, and semi-structured interviews from October to December 2013 with a cross-section of Iceland's political, economic, and scientific elite. Results indicate that Iceland is trying to capitalize on the increasing global visibility and economic opportunities in the Arctic while working to ensure regional geopolitical and environmental stability. While Iceland generally welcomes Chinese overtures into Arctic political and scientific spheres, the response to economic overtures is more nuanced. Specifically, Iceland is trying to balance a desire for economic gains, Chinese investment in Icelandic industries, and an associated ability to ‘scale up’ economically with a perceived vulnerability to being dominated by a country which dwarfs Iceland in both size, power, and influence. [ABSTRACT FROM PUBLISHER]

As a response to the threat of climate change, many nations are increasing their use of renewable energy, including wind energy. Large wind farms often conflict with other land uses, particularly tourism, which is a growing industry worldwide. In Iceland, tourism has recently become the largest export sector, with majority of tourists travelling to the country to experience its nature. This paper examines tourists' opinions and perceptions of wind power development in the Southern Highlands of Iceland and compares how number, size and proximity of wind turbines, and the landscape in which they are situated, influence tourists' perceptions. The study is based on an on-site questionnaire survey conducted in 2015. The results indicate that one-third of the travellers would be less likely to visit the Southern Highlands if a proposed wind farm were built, and two-thirds think that wind turbines would decrease the area's attractiveness. [ABSTRACT FROM AUTHOR]

Copyright of Cuadernos de Investigación Geográfica is the property of Universidad de la Rioja, Servicio de Publicaciones and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Climate changes in the 21st century are expected to significantly increase ocean temperatures and modify other oceanographic conditions in the North Atlantic. Marine biological research suggests that the impacts on the commercially most important fish stocks in the Icelandic-Greenland ecosystem may well be quite substantial. This will obviously lead to a corresponding impact on the economies of these two countries. However, the timing, extent and biological impact of global warming is quite uncertain. As a result the economic impact is similarly uncertain. This paper attempts to provide estimates of the impact of altered fish stocks due to global warming on the Icelandic and Greenland economies. The approach is one of stochastic simulations. This involves essentially three steps. The first is to obtain predictions of the impact of global warming on fish stocks and the associated probability distribution. For this we rely on recent marine biological predictions. The second step is to estimate the role of the fisheries sector in the two economies. This is done with the help of modern econometric techniques based on economic growth theory and historical data. Obviously these estimates are also subject to stochastic errors and uncertainty. The third step is to carry out Monte Carlo simulations on the basis of the above model and the associated uncertainties. The result of the Monte Carlo simulations consists of a set of dynamic paths for GDP over time with an expected value and a probability distribution for each future year. On this basis it is possible to calculate confidence intervals for the most likely path of GDP over time. The results indicate that the fisheries impact of global warming on the Icelandic GDP is more likely to be positive than negative but unlikely to be of significant magnitude compared to historical economic growth rates and fluctuations. The uncertainty of this prediction, however, is large. For Greenland, the impact on fish stocks and the CDP is highly likely to be positive and quite substantial relative to the current GDP. Due to less knowledge of the relationship between the fisheries sector and the Greenland economy, however, the confidence interval of this prediction is even wider than in the case of Iceland. [ABSTRACT FROM AUTHOR]

Decarbonisation of stationary energy supply, particularly electricity grids, is the current focus of climate change mitigation policy. However, studies have suggested that this narrow policy focus is insufficient to achieve meaningful global emissions reductions. Using Iceland as a case study, this paper demonstrates that significant emissions arise from transport and imported products, which are often not fully captured in territorial GHG inventories. This results in high greenhouse gas emissions per capita regardless of the nation's domestic energy supply. The result is a low carbon illusion in which rich economies believe they are reducing their GHG responsibility whilst global emissions continue to grow. This paper presents the first consumption-based carbon footprint (CBCF) analysis for Iceland, a nation where the stationary energy supply is 99% renewable, and could be viewed as a decarbonisation ‘future case’ for rich nations globally. The study combines Icelandic household expenditure data with the Multi-Regional Input-Output database Eora to calculate the CBCF of Icelandic households. The average annual CBCF of Icelandic households was 10.4 tCO 2 eq/capita, similar in magnitude to other EU nations despite Iceland's unique energy supply. GHG emissions from transport, food and goods dominated the household CBCF. The national CBCF was higher than most European nations and 55% higher than the territorial emissions inventory. Approximately 71% of household emissions were attributed to imported goods, which were mapped globally revealing that the GHG emissions burden of Icelandic consumption falls primarily on developing nations. The findings suggest that a broader GHG accounting framework and resulting policy focus is required, both in Iceland and globally, that incorporates both supply and demand-based GHG reduction strategies. [ABSTRACT FROM AUTHOR]

Natural disasters can have serious consequences which differ between countries. Local conditions, therefore, have to be considered when discussing risk sharing for natural disasters. This study focuses on the natural catastrophe insurance system in Iceland with a special focus on climate change and the public and private insurance system, as such a study has not been carried out previously. Findings are placed in Nordic and European contexts, suggesting that the Icelandic insurance system with regard to natural disasters is rather complex. Furthermore, land-use planning seems to be a key issue for the public insurance sector, while low climate change awareness concerns the private sector. Policymakers and authorities in other countries can benefit from the study, e.g. integration of public systems for risk analysis and assessment of financial risks. The learning point for Icelandic policymakers and insurance companies is that the risk of flooding is uninsured in some cases, which may be of concern as more flooding is expected due to climate change. [ABSTRACT FROM AUTHOR]

In the northern hemisphere, there are six permanent or semi-permanent atmospheric activity centers, namely the Icelandic Low, Aleutian Low, India Low, Mongolia High, North Pacific High, and North Atlantic High. The first four are semi-permanent action centers and the last two are permanent circulation systems. The India Low exists only during the summer. By using 160 years (1850-2009) of monthly mean sea level pressure data from the Hadley Centre in the UK, we conduct a comprehensive study of the five boreal winter atmospheric centers of action (ACAs). Based on a unified definition and a method determined in previous studies, we calculate the indices of areal coverage (S), intensity (P), and position of action center ( λ , φ ) for each of these five ACAs. Through an in-depth analysis of these indices and their relationships with climate variables, we evaluate the indices by describing and explaining areal climate anomalies, particularly precipitation and temperature anomalies in China. We show that (1) ACAs significantly influence the climate anomalies of surrounding areas (2) the influences of oceanic ACAs are larger and the intensity anomalies of ACAs have a greater impact than their location displacement, and (3) ACAs exert more control on temperature than they do on precipitation. For the two ACAs over the north Atlantic, the impacts of their intensities on the anomalies of temperature and precipitation are similar. For the two ACAs over the north Pacific, their influences are almost the opposite. The most influential ACA for climate anomalies in China during the boreal winter is HMO. When HMO is stronger, China has a colder winter and it is wetter in the north. With stronger ACAs in the upstream, i.e., the Icelandic Low and North Atlantic High, northern China has a warmer winter. The ACAs over the north Pacific exert little influence on climate anomalies in China during winter. The analyses presented in this paper provide a set of useful indices for defining and describing ACAs, and they suggest insightful applications for these indices. [ABSTRACT FROM AUTHOR]

Carbon-based systems of energy are rapidly unravelling. The imperative of climate emergency is reshaping energy landscapes, in some instances leading to the reappraisal of energy options hitherto sidelined. This paper deals with the emerging energy landscapes of the Netherlands and Iceland through historically informed tales that focus on islands. While vastly different in historical and geographical context and scale, these cases reveal the necessity of geographical nuance facilitated by the ways insular places offer insights into energy imaginaries of the Anthropocene. The former is a historicised narrative about the reinvention of wind energy as natural gas is being ousted. It focuses on the proposed Dogger Bank Power Link Islands, the first of which is scheduled to emerge in the coming years. The latter, also historically informed, identifies the context for current large wind energy proposals in Iceland, and then contrasts these with the authors' empirical observations from the small peripheral island of Grímsey. There wind energy is also being reinvented for ousting the predominant oil infrastructure on the island. These cases represent experimental opportunities for envisioning Anthropocene futures intended to destabilize imaginaries of growth in ways that open spaces for negotiation and contestation. They problematize dominant narratives that render wind energy development visible and knowable as a necessary intervention. Emergent from this is wind's decentred energy landscape in the Anthropocene; an epoch where energy is revealed in its importance to our societies, dispelling the human exceptionalism implicit in the nomenclature whilst at the same time showing how our actions come to matter. The collision of the Earth and ourselves under the terms of climate emergency begs the question whether our differences are the only ones that matter? But also, if it matters what we have done, then surely it matters what we have not done and chosen to ignore. [ABSTRACT FROM AUTHOR]

Past human land-use is increasingly recognized as a driver of ecosystem change in seemingly natural landscapes. Quantification of historical land use is therefore critical for assessing the degree of human impact and requires integration of geography, ecology and history. This paper examines the impact of climate change, land-use and exposure to international markets on the terrestrial ecology in Suðursveit, in southeast Iceland between AD 1700 and 1901. For this we use historical data concerning land-use, livestock and demography, and mapping of glacier advance, glacier outburst floods (jökulhlaups) and agricultural land. Change in land-use or population during the eighteenth century was insignificant. Population declined in the first two decades of the nineteenth century due to the advance of Breiðamerkurjökull glacier. After AD 1820, Suðursveit became part of international market for agricultural products, which facilitated population and livestock increase. This led to overgrazing and severe land degradation in the nineteenth century. [ABSTRACT FROM AUTHOR]

Paleoclimate reconstructions across Iceland provide a template for past changes in climate across the northern North Atlantic, a crucial region due to its position relative to the global northward heat transport system and its vulnerability to climate change. The roles of orbitally driven summer cooling, volcanism, and human impact as triggers of local environmental changes in the Holocene of Iceland remain debated. While there are indications that human impact may have reduced environmental resilience during late Holocene summer cooling, it is still difficult to resolve to what extent human and natural factors affected Iceland's late Holocene landscape instability. Here, we present a continuous Holocene fire record of northeastern Iceland from proxies archived in Stóra Viðarvatn sediment. We use pyrogenic polycyclic aromatic hydrocarbons (pyroPAHs) to trace shifts in fire regimes, paired with continuous biomarker and bulk geochemical records of soil erosion, lake productivity, and human presence. The molecular composition of pyroPAHs and a wind pattern reconstruction indicate a naturally driven fire signal that is mostly regional. Generally low fire frequency during most of the Holocene significantly increased at 3 ka and again after 1.5 ka BP before known human settlement in Iceland. We propose that shifts in vegetation type caused by cooling summers over the past 3 kyr, in addition to changes in atmospheric circulation, such as shifts in North Atlantic Oscillation (NAO) regime, led to increased aridity and biomass flammability. Our results show no evidence of faecal biomarkers associated with human activity during or after human colonisation in the 9th century CE. Instead, faecal biomarkers follow the pattern described by erosional proxies, pointing toward a negligible human presence and/or a diluted signal in the lake's catchment. However, low post-colonisation levels of pyroPAHs, in contrast to an increasing flux of erosional bulk proxies, suggest that farming and animal husbandry may have suppressed fire frequency by reducing the spread and flammability of fire-prone vegetation (e.g. heathlands). Overall, our results describe a fire frequency heavily influenced by long-term changes in climate through the Holocene. They also suggest that human colonisation had contrasting effects on the local environment by lowering its resilience to soil erosion while increasing its resilience to fire. [ABSTRACT FROM AUTHOR]

The paper presents a synthesis of some of the interdisciplinary work from the ARCPATH project that focuses on the effects of climate change on Arctic social-ecological systems. It does so through the prism of whales and their recreational ecosystem services (ES). Whales present a group of species that are vulnerable to climate change and, at the same time, are central to the economies, cultures, and identities of many Arctic coastal communities. One such community is the town of Húsavík in Skjálfandi Bay, Iceland. The paper conducts an initial literature review to examine the effects of climate change on whales, globally, before using these findings and site-specific data from climate change modelling, whale observations from whale watching boats and whale watching trip records to investigate possible future impacts on whale watching in Skjálfandi Bay. The literature review identifies three categories of impacts on whales due to climate change, which concern changing distributions and migration, prey availability, and sea-ice and ocean temperature. Linear regression models identify statistically significant relationships between sea-surface temperatures (SST) and cetacean sightings for minke whales, blue whales and white-beaked-dolphins over the period 1995 to 2017. These species appear to have changed their usual feeding areas, and the results imply that further increases in SST are likely to further affect whale distributions. Future climate scenarios indicate that at least 2 °C of SST warming in Skjálfandi Bay up to 2050 might be inevitable regardless of the future emissions scenario, which implies nearly certain change that would require adaptation. The reliance of the local tourism sector on whale watching makes Húsavík vulnerable to the effects of climate change on whales. The results of this interdisciplinary inquiry emphasize the interconnectedness of different components of social-ecological systems and calls for adaptation planning that would enhance the resilience of local community to climate change and conservation measures that could enhance the protection of whales beyond the scope of the current whale sanctuary in Skjálfandi Bay. [ABSTRACT FROM AUTHOR]

The Overturning in the Subpolar North Atlantic Program (OSNAP) was initiated in the spring of 2010 through a collaborative effort involving the USA, the UK, Germany, the Netherlands and Canada. A key feature of OSNAP is a trans-basin observing system deployed in the summer of 2014 for the continuous measure of volume, heat and freshwater fluxes in the subpolar North Atlantic. This review focuses on advancements made possible by the collective OSNAP observations. Chief among those advancements is the quantification of the dominant role of the eastern subpolar North Atlantic in the production of dense waters that reside in the lower limb of the overturning: the Irminger and Iceland basins contributed approximately three times as much dense water compared with the Labrador Sea over the observational period. Other advancements include elucidation of the relationship between convective activity in the basin interior and boundary current anomalies; the spread of overflow waters in the subpolar region; the seasonality of the meridional volume, heat and freshwater fluxes; and the challenges involved in designing a simpler, less costly observing system. Collectively, OSNAP measurements are laying a framework on which to assess the overturning circulation's vulnerability to continued warming and freshening as climate change continues apace. This article is part of a discussion meeting issue 'Atlantic overturning: new observations and challenges'. [ABSTRACT FROM AUTHOR]

With the EU-funded PACE (Permafrost and Climate in Europe) project at the turn of this century, several deep boreholes (100 m +) were drilled in European mountain sites, including in mainland Norway, Svalbard and Sweden. During other projects from 2004 and the International Polar Year (IPY) period in 2006–2007, several additional boreholes were drilled in different sites in both Norway and Iceland, measuring temperatures along both altitudinal and latitudinal gradients. At most sites, multi-temporal geophysical soundings are available using electrical resistivity tomography (ERT). Here, we study the development of permafrost and ground temperatures in mainland Norway and Iceland based on these data sets. We document that permafrost in Norway and Iceland is warming at a high rate, including the development of taliks in both Norway and Iceland in response to global climate change during the last 20 years. At most sites, ground surface temperature (GST) is apparently increasing more strongly than surface air temperature (SAT). Changing snow conditions appear to be the most important factor for the higher GST rates. Modelling exercises also indicate that the talik development can be explained by both higher air temperatures and increasing snow depth. [ABSTRACT FROM AUTHOR]

The first two parts of this series (Klevberg and Oard, 2011a, 2011b) introduced methods of studying past climate change, the historicity of the Medieval Warm Period and Little Ice Age, and the importance of the Little Ice Age in understanding climate change and constraining climatic models. The third part (Klevberg and Oard, 2012) provided more detailed reasons for concentrating on the North Atlantic region and summarized the rich climatic and glaciologic history of Iceland. Our study of the effects of the Little Ice Age in the North Atlantic region continues with this paper, which presents a summary of climate change indicators and the history of the Little Ice Age in Norway. [ABSTRACT FROM AUTHOR]

The objectives of this paper are to define the present and past terrestrial fluxes of carbon in three river catchments in northeast Iceland and assess the effect of land degradation and future climate change on the fluxes. The carbon fluxes are: (1) present gross primary production (GPP); (2) net primary production (NPP); (3) net ecosystem exchange (NEE) of terrestrial vegetation in the catchments; (4) river transport out of the catchments of dissolved inorganic carbon (DIC) in 1998; (5) dissolved organic carbon (DOC); (6) river particulate organic carbon (POC); and (7) the average present (prNBE) and (8) past 10 000 years net biome exchange (NBE10 000). The GPP is the largest of the carbon fluxes and increases from west to east as vegetation cover and bedrock age increase. The NPP and NEE, however, were highest in the Jökulsá á Dal catchment where wetlands are extensive. The DIC flux is the largest of the river export fluxes, being highest when the GPP is lowest, dictated by the rapid chemical weathering rate of the young basaltic rocks, rather than vegetation. Thus, a greater portion of the autotrophic and heterotrophic respiration escapes to the atmosphere where the GPP is largest. The NBE10 000 rate increases from west to east. The prNBE is negative and larger than the small positive NBE10 000 flux in the Jökulsá á Fjöllum and it is also negative in the Fellsá catchments, indicating land degradation. Conversely, the prNBE is positive and higher than NBE10 000 in the Jökulsá á Dal catchment, where soil organic carbon stock is increasing. In the future, NBE of two of the three catchments will probably increase because of climate warming and consequently increased vegetation cover and ecosystem stability. [ABSTRACT FROM AUTHOR]

Aim: How plants can disperse in response to global change is a critical question, yet major knowledge gaps persist about long‐distance dispersal (LDD) mechanisms. We studied the potential a migratory waterfowl has for LDD of flowering plants via gut passage of seeds (endozoochory), comparing spring and autumn migration. Location: United Kingdom and Iceland. Taxon: Pink‐footed Goose (Anser brachyrhynchus, Baillon) and Angiosperma. Methods: We studied endozoochory by Pink‐footed geese migrating within and between the UK and Iceland by faecal sampling and GPS tracking. We collected 614 faecal samples from 14 areas in the UK and one in Iceland. Using GPS tracks to and from these areas, we estimated how far seeds can be dispersed by Pink‐footed geese, and where to or from. Results: We recorded 5507 intact seeds of 35 species (27 terrestrial) from 15 plant families, with lower seed abundance per dropping when birds were migrating northwards in the UK during spring than upon their arrival in autumn. Species richness of plant seeds was highest in Iceland and in autumn. Only four plant species dispersed had an "endozoochory syndrome". GPS movements showed that seeds retained in guts for up to 24 h can be readily dispersed in both directions between the UK and Iceland, with maximum distances exceeding 2000 km, as well as between UK localities separated by 100 s of km. Movements northwards of ≤400 km were even recorded in autumn. While at stopover sites, daily movements between roost and feeding sites often exceed 20 km. Main Conclusions: Pink‐footed geese are LDD vectors for plants previously assumed to lack an LDD mechanism. Spring migration is not the only period when geese move plants to cooler latitudes. The pink‐footed goose can allow terrestrial and aquatic plants to cross the ocean and to keep pace with climate change. [ABSTRACT FROM AUTHOR]

Despite of their importance for sea-level rise, seasonal water availability, and as source of geohazards, mountain glaciers are one of the few remaining sub-systems of the global climate system for which no globally applicable, open source, community-driven model exists. Here we present the Open Global Glacier Model (OGGM, http://www.oggm.org), developed to provide a modular and open source numerical model framework for simulating past and future change of any glacier in the world. The modelling chain comprises data downloading tools (glacier outlines, topography, climate, validation data), a preprocessing module, a mass-balance model, a distributed ice thickness estimation model, and an ice flow model. The monthly mass-balance is obtained from gridded climate data and a temperature index melt model. To our knowledge, OGGM is the first global model explicitly simulating glacier dynamics: the model relies on the shallow ice approximation to compute the depth-integrated flux of ice along multiple connected flowlines. In this paper, we describe and illustrate each processing step by applying the model to a selection of glaciers before running global simulations under idealized climate forcings. Even without an in-depth calibration, the model shows a very realistic behaviour. We are able to reproduce earlier estimates of global glacier volume by varying the ice dynamical parameters within a range of plausible values. At the same time, the increased complexity of OGGM compared to other prevalent global glacier models comes at a reasonable computational cost: several dozens of glaciers can be simulated on a personal computer, while global simulations realized in a supercomputing environment take up to a few hours per century. Thanks to the modular framework, modules of various complexity can be added to the codebase, allowing to run new kinds of model intercomparisons in a controlled environment. Future developments will add new physical processes to the model as well as tools to calibrate the model in a more comprehensive way. OGGM spans a wide range of applications, from ice-climate interaction studies at millenial time scales to estimates of the contribution of glaciers to past and future sea-level change. It has the potential to become a self-sustained, community driven model for global and regional glacier evolution. [ABSTRACT FROM AUTHOR]

This paper focuses on the relationship between atmospheric circulation and solid precipitation (SP) happening in the weather station of Isola 2000. Located in the French department of the Alpes-Maritimes at an altitude of 1912 m, it has the oldest series of daily SP and snow depth (SD) observations from the department. Study has two objectives, analyzed past orientations concerning air temperature, SP and SD, then, characterizes and explains the atmospheric circulation condition producing SP. Results show a warming of air temperature since the early 2000s, counterintuitive accompanied by an increase in the frequency of SP and a larger thickness of SD. In addition, by crossing SP observations with ERA-INTERIM reanalysis (EI-R), seven covariations have been measured: vertical velocity 700 hPa; specific humidity 850 hPa; sea level pressure; air temperature 850 hPa; geopotential height 700 hPa; U-component of wind 700 hPa, V-component of wind 700 hPa. The mapping of these variables shows two types of atmospheric circulation implicated in SP: westerly cyclonic circulation, producing SP in the range of 1–5 cm and 6–20 cm; southern circulation with a depression focused on Iceland and a trough on Western Europe, causing SP in the range of 21–40 cm and 41–93 cm. [ABSTRACT FROM AUTHOR]

Phytoplankton play a crucial role in the marine food web and are sensitive indicators of environmental change. Iceland is at the center of a contrasting hydrography, with cold Arctic water coming in from the north and warmer Atlantic water from the south, making this geographical location very sensitive to climate change. We used DNA metabarcoding to determine the biogeography of phytoplankton in this area of accelerating change. Seawater samples were collected in spring (2012–2018), summer (2017) and winter (2018) together with corresponding physico-chemical metadata around Iceland. Amplicon sequencing of the V4 region of the 18S rRNA gene indicates that eukaryotic phytoplankton community composition is different between the northern and southern water masses, with some genera completely absent from Polar Water masses. Emiliania was more dominant in the Atlantic-influenced waters and in summer, and Phaeocystis was more dominant in the colder, northern waters and in winter. The Chlorophyta picophytoplankton genus, Micromonas, was similarly dominant to the dominant diatom genus, Chaetoceros. This study presents an extensive dataset which can be linked with other 18s rRNA datasets for further investigation into the diversity and biogeography of marine protists in the North Atlantic. [ABSTRACT FROM AUTHOR]

The Barmur Group (informally Tjörnes beds) sedimentary succession of northern Iceland is key to reconstructing the opening of the Bering Strait oceanic gateway because these rocks record migration of bivalve molluscs from the Pacific to the Atlantic via the Arctic. However, the timing of the migration event is poorly constrained owing to a lack of reliable absolute ages. To address this problem, we present the first Ar‐Ar radiometric dates from four basaltic lavas that underlie, are intercalated with, and overlie the Barmur Group, and integrate them with existing paleomagnetic records. We show that the Barmur Group has a latest Miocene to early Pliocene age range (c. 6.0–4.4 Ma; C3r–C3n.2n), older than all previous age models. Thus, the Barmur Group does not record the mid‐Piacenzian Warm Period, contra some previous suggestions. Abundant Pacific bivalve molluscs appeared in the Barmur Group during subchrons C3n.4n–C3n.3r at 5.235–4.896 Ma, over 1.3 million years earlier than previously suggested. Appearance of Pacific bivalves in the northern Atlantic occurred shortly after the 5.6–5.4 Ma age previously inferred for first appearance of Arctic bivalves in the Pacific. Thus, our data suggest that first opening of the Bering Strait gateway by the latest Miocene (c. 5.5 Ma) was soon followed by bidirectional trans‐Arctic faunal exchange, and argue against a hypothesized two‐stage faunal exchange process spanning c. 2 million years. Our results also confirm that first opening of the Bering Strait gateway was not directly associated with the growth of large northern hemisphere icesheets, which occurred several million years later. Plain Language Summary: The extent to which global climate change is influenced by the flow of seawater between the world's oceans is an important question in Earth science. Sedimentary rocks from the Tjörnes Peninsula in northern Iceland record the opening of the Bering Strait oceanic gateway, which connects the Pacific and Atlantic Oceans via the Arctic. The signature of this gateway opening event is the sudden appearance in Iceland of bivalve mollusc fossils that previously lived only in the Pacific Ocean. However, the timing of their arrival is uncertain owing to the lack of reliable age measurements. To solve this problem, we applied radioisotope dating methods to a succession of rocks called the Barmur Group from the Tjörnes Peninsula. We found that the sudden appearance of Pacific fossils occurred over a million years earlier than previously thought. Our data show that first opening of the Bering Strait gateway was soon followed by migration of marine faunas in both directions, in contrast to the existing hypothesis that Pacific‐to‐Atlantic migration significantly post‐dated Atlantic‐to‐Pacific migration. Our results also confirm the hypothesis that establishment of the Pacific‐Arctic‐Atlantic oceanic connection did not directly trigger development of large northern hemisphere icecaps, which occurred several million years later. Key Points: New Ar‐Ar dating shows a late Miocene to early Pliocene (6.0–4.4 Ma) age range for the Barmur Group (Tjörnes beds), northern IcelandArrival of Pacific bivalves in Iceland is dated at 5.2–4.9 Ma (chrons C3n.4n–C3n.3r), soon after first Bering Strait opening at 5.6–5.4 MaOpening of the Bering Strait gateway did not directly cause the development of large northern hemisphere icecaps [ABSTRACT FROM AUTHOR]

Mosses are among the first colonizing organisms after glacier retreat and can develop into thick moss mats during later successional stages. They are key players in N2 fixation through their microbiome, which is an important process for nutrient buildup during primary succession. How these moss–microbe interactions develop during succession is not well studied and is relevant in the light of climate change and increased glacier retreat. We examined how the bacterial communities associated with two moss species of the genus Racomitrium and the underlying soil, as well as moss traits and nitrogen fixation, develop along a successional gradient in the glacier forefield of Fláajökull in southeast Iceland. In addition, we tested whether moss functional traits, such as total carbon (TC) and total nitrogen (TN) contents, moss moisture content, and moss shoot length are drivers of moss and underlying soil bacterial communities. Although time since deglaciation did not affect TN and moss moisture contents, TC and shoot length increased with time since deglaciation. Moss and underlying soil bacterial communities were distinct. While the soil bacterial community structure was driven by moss C/N ratios, the moss bacterial community structure was linked to time since deglaciation, moss C/N ratio, and moss moisture content. Moss N2‐fixation rates were linked to bacterial community composition and nifH gene abundance rather than moss TN or time since deglaciation. This was accompanied by a shift from autotrophic to heterotrophic diazotrophs. Overall, our results suggest that there is little lateral transfer between moss and soil bacterial communities and that moss traits affect moss and soil bacterial community structure. Only moss bacterial community changed with time since deglaciation. In addition, moss N2‐fixation rates are determined by bacterial community structure, rather than moss traits or time since deglaciation. This study on the interplay between succession, mosses, soils, and their bacterial communities will inform future work on the fate of newly exposed areas as a result of glacier retreat. [ABSTRACT FROM AUTHOR]

The Atlantic Meridional Overturning Circulation (AMOC) is a key mechanism of poleward heat transport and an important part of the global climate system. How it responded to past changes in forcing, such as those experienced during Quaternary interglacials, is an intriguing and open question. Previous modelling studies suggest an enhanced AMOC in the mid-Holocene compared to the preindustrial period. In earlier simulations from the Palaeoclimate Modelling Intercomparison Project (PMIP), this arose from feedbacks between sea ice and AMOC changes, which were dependent on resolution. Here we present an initial analysis of recently available PMIP4 simulations for three experiments representing different interglacial conditions – one 127 000 years ago within the Last Interglacial (127 ka, called lig127k), one in the middle of the Holocene (midHolocene, 6 ka), and a preindustrial control simulation (piControl, 1850 CE). Both lig127k and midHolocene have altered orbital configurations compared to piControl. The ensemble mean of the PMIP4 models shows the strength of the AMOC does not markedly change between the midHolocene and piControl experiments or between the lig127k and piControl experiments. Therefore, it appears orbital forcing itself does not alter the overall AMOC. We further investigate the coherency of the forced response in AMOC across the two interglacials, along with the strength of the signal, using eight PMIP4 models which performed both interglacial experiments. Only two models show a stronger change with the stronger forcing, but those models disagree on the direction of the change. We propose that the strong signals in these two models are caused by a combination of forcing and the internal variability. After investigating the AMOC changes in the interglacials, we further explored the impact of AMOC on the climate system, especially on the changes in the simulated surface temperature and precipitation. After identifying the AMOC's fingerprint on the surface temperature and rainfall, we demonstrate that only a small percentage of the simulated surface climate changes could be attributed to the AMOC. Proxy records of sedimentary Pa/Th ratio during the two interglacial periods both show a similar AMOC strength compared to the preindustrial, which fits nicely with the simulated results. Although the overall AMOC strength shows minimal changes, future work is required to explore whether this occurs through compensating variations in the different components of AMOC (such as Iceland–Scotland overflow water). This line of evidence cautions against interpreting reconstructions of past interglacial climate as being driven by AMOC, outside of abrupt events. [ABSTRACT FROM AUTHOR]

The article discusses a research paper on the rise of some parts of Iceland, which references a study by Kathleen Compton et al., published in a 2015 issue of "Geophysical Research Letters," and the role of climatic change in these events.

Together, biological soil crust (BSC) and other cryptogamic groundcovers can contribute up to half of the global nitrogen (N) fixation. BSC also stabilizes the soil (reducing erosion and dust emissions), fixes carbon (C), retains moisture and acts as a hotspot of microbial diversity and activity. Much of the knowledge about how climate change is affecting the composition and functioning of BSC comes from hot arid and semiarid regions. The comparatively smaller body of research on BSC from cold and mesic environments has been primarily observational, for example along chronosequences after a glacier retreat. Few studies have experimentally investigated the effects of the environment on BSC from high latitudes. Such experiments allow unraveling of relationships at a resolution that can only be achieved by controlling for confounding factors. We measured short‐term (2–4 days) responses of a liverwort‐based Anthelia juratzkana BSC from the south of Iceland to a range of temperature, moisture and light conditions. Warming increased N fixation rates, especially when moisture was at a saturation level, and only when light was not limiting. A correlation analysis suggests that increases in N fixation rates were linked to cyanobacterial abundance on the BSC surface and to the rates of their metabolic activity. Warming and moisture changes also induced compositional and structural modification of the bacterial community, with consequences at the functional level. In contrast to many observations on BSC from hot drylands, the BSC from our cold and mesic study site is more limited by low temperature and light than by moisture. Our findings show possible ways in which BSC from cold and mesic ecosystems can respond to short‐term manifestations of climate change, such as increasingly frequent heat waves. [ABSTRACT FROM AUTHOR]

The establishment of baseline information on biodiversity is important as contemporary biodiversity might act as a bioindicator of environmental change. It is especially important at locations which are expected to be largely impacted by climate change, such as Icelandic waters. The present study focuses on the diversity of bryozoan species in Iceland. An Icelandic bryozoan species list was compiled from three main data sources: species collected during the BIOICE programme, species deposited in old museum collections and from literature. A total of 288 species were recorded from the study area, 67 of which are new records in Icelandic waters and three are potentially non-indigenous species. Such diversity is relatively high in comparison to other areas and yet predicted to be even higher if more studies were to be conducted. Encrusting forms (56%) were by far the most numerous among studied bryozoans. The highest number of species (71) was recorded in the shallowest 0–100 m zone which is most likely a result of complex factors including high primary productivity of that zone. This study reveals a large proportion of new species records for the area, showing how little is known about bryozoan diversity and its ecological aspects in such important areas as Icelandic waters. It is a starting point for further in-depth investigations of this specific group of organisms. [ABSTRACT FROM AUTHOR]

We use biochemical, biological, archaeological, and historical analysis to examine relationships between Atlantic cod migration, sea temperature, and shifts in the distribution and occupancy of historical fishing sites in Iceland during the last millennium. Results support the hypothesis that the cooling climate of the North Atlantic during the period commonly referred to as the Little Ice Age coincided with changes in Atlantic cod migration patterns. Historical analysis shows a concomitant increase in reports of worsening Atlantic cod fishing and a severe decrease in domestic fishing, particularly in north Iceland. We conclude thatAtlantic cod fisheries in Iceland originally thrived because of the proximity to codmigration routes. However, despite themobility of local fishers, fluctuations in fish migrations, coupled with a harsher climate and increased competition for fishing grounds, resulted in a stagnation that lasted until the eventual modernization of the fishery in the mid-nineteenth century. [ABSTRACT FROM AUTHOR]

This paper explores the fate and transport of microbial contamination in a cold climate and coarse aquifers. A confirmed norovirus outbreak in a small rural water supply in the late summer of 2004, which is estimated to have infected over 100 people, is used as a case study. A septic system, 80 m upstream of the water intake, is considered to have contaminated drinking water. Water samples tested were negative for coliform and strongly positive for norovirus. Modelling predicts that a 4.8-log10 removal was possible in the 8 m thick vadose zone, while only a 0.7-log10 and 2.7-log10 removal in the aquifer for viruses and Escherichia coli, respectively. The model results support that the 80 m setback distance was inadequate and roughly 900 m aquifer transport distance was needed to achieve 9-log10 viral removal. Sensitivity analysis showed that the most influential parameters on model transport removal rate are grain size diameter and groundwater velocity, temperature and acidity. The results demonstrate a need for systematic evaluation of septic systems in rural areas in lesser studied coarse strata at low temperatures, thereby strengthening data used for regulatory requirements for more confident determination on safe setback distances. [ABSTRACT FROM AUTHOR]

Understanding the ecological requirements and thresholds of individual species is crucial to better predict potential outcomes of climate change on species distribution. In particular, species optima and lower and upper limits along resource gradients require attention. Based on Huisman‐Olff‐Fresco (HOF) models, we determined species‐specific responses along gradients of nine environmental parameters including depth in order to estimate niche attributes of 30 deep‐sea benthic amphipods occurring around Iceland. We, furthermore, examined the relationships between niche breadth, occupancy, and geographic range assuming that species with a wider niche are spatially more widely dispersed and vice versa. Overall, our results reveal that species react very differently to environmental gradients, which is independent of the family affiliation of the respective species. We could infer a strong relationship between occupancy and geographic range and also relate this to differences in niche breadth; that is specialist species with a narrow niche had a more limited distribution and may thus be more threatened by changing environmental conditions than generalist species, which are more widespread. Given the preponderance of rare species in the deep sea, this implies that many species could be at risk. However, this must be carefully weighed against geographical data gaps in this area, given that many deep‐sea areas are severely undersampled and the true distribution of most species is unknown. After all, our results underline that an accurate taxonomic classification is of crucial importance, without which ecological niche properties cannot be determined and which is hence fundamental for the assessment and understanding of changes in biodiversity in the face of increasing human perturbations. [ABSTRACT FROM AUTHOR]

Based on newly-available meteorological reanalysis, we compile and present extended seasonal series of the North Atlantic Oscillation (NAO) and Greenland Blocking indices spanning 1800–2020, which we analyse for evidence of significant trends. This represents a major backward extension of the previously available instrumental-/reanalysis-based Azores–Iceland and principal component-based NAO indices, and allows us to evaluate the potential effect of natural climate perturbations, especially the 1809 and 1815 major volcanic eruptions and ~1790s–1830 Dalton solar minimum, on North Atlantic atmospheric circulation. We find that winters 1809/10 and 1816/17 mark positive NAO peaks, relative to several years before and afterwards, which is in accordance with the theory of volcanic forcing of climate. However, there is little evidence of a summer NAO volcanic signature. Overall, based on the significantly longer new reanalysis time series, the new series presented here corroborate and extend our previous results of: (1) a significantly more variable year-to-year NAO with a recent exceptional clustering of extreme events since 2000 for winter; (2) a significant increasing trend in blocking over Greenland in summer. These trends have major repercussions for the probability of the occurrence of extreme weather events over northwest Europe and for the sensitivity and response of the Greenland Ice Sheet to global warming, especially if they continue as an integral part of anthropogenic climate change. [ABSTRACT FROM AUTHOR]

Abstract: The pre-industrial natural carrying capacity is believed to have limited the human population in Iceland to a maximum of fifty to sixty thousand inhabitants. Since AD 1800 the Icelandic population has gradually grown up to nearly 300 thousand in 2005. In this paper a simple approach is used to evaluate the potential population size that the pre-industrial Icelandic environment could possibly sustain. A dynamic model was constructed that simulates the population size according to potential biological production available for livestock. Biological production was determined by the extent of the total potential vegetation cover based on the Degree-Day concept. Fluctuations in the mean annual temperature causes changes in the potential vegetation cover and as a consequence change the biological production sustaining livestock and ultimately human population. The simulation''s results indicate that the potential population that the Icelandic environments could sustain during the pre-industrial period fluctuated between 40 and 80 thousand. The results further indicate that the severe land degradation experienced after the Viking settlement period in AD 900 had a marginal impact on the population size. The pre-historical population did however overshoot the natural sustainability on several occasions. [Copyright &y& Elsevier]

This study is a part of a Nordic co-operative research project, Climate and Energy, funded by Nordic Energy Research and the Nordic energy sector. The project has the objective of a comprehensive assessment of the impact of climate change on Nordic renewable energy resources including hydropower, wind power, biofuels and solar energy. In this paper, the long term variability of precipitation, temperature and discharge of Icelandic rivers is analyzed with respect to trends. Trend is tested for two periods: 1941-2002, since the longest Icelandic discharge records reach 60 years back in time, and 1961-2000, so that a larger set of discharge records could be included, as only a few Icelandic discharge records extend more than 40 years back in time. An eventual trend in the time series is analyzed using the Mann-Kendall test. The test is applied to the time series of both annual and seasonal values, and also to the timing and volume of the maximum daily discharge in spring and autumn, respectively. The main conclusions from the study are that, despite significant increase in measured precipitation, discharge in non-glacial rivers has not increased. Meanwhile, spring temperatures have a negative trend and spring floods, therefore, are larger and delayed. [ABSTRACT FROM AUTHOR]

Climate change alters species distributions by shifting their fundamental niche in space through time. Such effects may be exacerbated by increased inter-specific competition if climate alters species dominance where competitor ranges overlap. This study used census data, telemetry and stable isotopes to examine the population and foraging ecology of a pair of Arctic and temperate congeners across an extensive zone of sympatry in Iceland, where sea temperatures varied substantially. The abundance of Arctic Brünnich's guillemot Uria lomvia declined with sea temperature. Accessibility of refugia in cold water currents or fjords helped support higher numbers and reduce rates of population decline. Competition with temperate Common guillemots Uria aalge did not affect abundance, but similarities in foraging ecology were sufficient to cause competition when resources are limiting. Continued warming is likely to lead to further declines of Brünnich's guillemot, with implications for conservation status and ecosystem services. [ABSTRACT FROM AUTHOR]

Due to climate change, worldwide glaciers are rapidly declining. The trend will continue into the future, with consequences for sea level, water availability and tourism. Here, we assess the future evolution of all glaciers in Scandinavia and Iceland until 2100 using the coupled surface mass-balance ice-flow model GloGEMflow. The model is initialised with three distinct past climate data products (E-OBS, ERA-I, ERA-5), while future climate is prescribed by both global and regional climate models (GCMs and RCMs), in order to analyze their impact on glacier evolution. By 2100, we project Scandinavian glaciers to lose between 67 ± 18% and 90 ± 7% of their present-day (2018) volume under a low (RCP2.6) and a high (RCP8.5) emission scenario, respectively. Over the same period, losses for Icelandic glaciers are projected to be between 43 ± 11% (RCP2.6) and 85 ± 7% (RCP8.5). The projected evolution is only little impacted by both the choice of climate data products used in the past and the spatial resolution of the future climate projections, with differences in the ice volume remaining by 2100 of 7 and 5%, respectively. This small sensitivity is attributed to our model calibration strategy that relies on observed glacier-specific mass balances and thus compensates for differences between climate forcing products. [ABSTRACT FROM AUTHOR]

Population dynamics, movement patterns and migratory routes of common minke whales (Balaenoptera acutorostrata) in the North Atlantic are not yet fully understood. Small-scale movements of minke whales within Skjálfandi Bay, Iceland, were analysed and discussed in relation to population dynamics in the North Atlantic. Local distribution and abundance of minke whales were investigated on both individual and population basis. Data were obtained through continuous sighting surveys from 2005 to 2018, conducted by trained volunteers using whale watching vessels as opportunistic research platforms. Variations in abundance might reflect a species distribution shift to higher latitudes. Competition for prey and the general movement of several species from different taxonomic groups support a potential range shift. For the first time, habitat use of minke whales in Skjálfandi Bay was revealed through spatial analysis, as well as small-scale site-tenacity, proven through modelling of distances between individual and random relocations. To improve the status of the declining minke whale population around Iceland we suggest recognition of separate minke whale management units using different areas. Additionally, we encourage the protection of different feeding grounds which will reduce local anthropogenic stressors and likely improve minke whales' coping with climate change and shifts in prey. [ABSTRACT FROM AUTHOR]

Biomass burning influences global atmospheric chemistry by releasing greenhouse gases and climate-forcing aerosols. There is controversy about the magnitude and timing of Holocene changes in biomass burning emissions from millennial to centennial timescales and, in particular, about the possible impact of ancient civilizations. Here we present a 5 kyr record of fire activity proxies levoglucosan, black carbon, and ammonium measured in the RECAP (Renland ice cap) ice core, drilled in coastal eastern Greenland, and therefore affected by processes occurring in the high North Atlantic region. Levoglucosan and ammonium fluxes are high from 5 to 4.5 kyr BP (thousand years before 2000 CE) followed by an abrupt decline, possibly due to monotonic decline in Northern Hemisphere summer insolation. Levoglucosan and black carbon show an abrupt decline at 1.1 kyr BP, suggesting a decline in the wildfire regime in Iceland due to the extensive land clearing caused by Viking colonizers. All fire proxies reach a minimum during the second half of the last century, after which levoglucosan and ammonium fluxes increase again, in particular over the last 200 years. We find that the fire regime reconstructed from RECAP fluxes seems mainly related to climatic changes; however over the last millennium human activities might have influenced wildfire frequency/occurrence substantially. [ABSTRACT FROM AUTHOR]

The growing recognition that global climatic change is a pressing reality and that its impacts on humans and ecological systems are inevitable makes adaptation a core topic in climate change research and policymaking. The glacier tourism sector that is highly sensitive towards changing climatic conditions is among the most relevant in this respect. This study aims to examine empirically how adaptation to climate change impacts is practiced by small- and middle-scale glacier tour operators. Data was collected by means of a set of semi-structured interviews with the managers or owners of nine small- or middle-scale tour companies operating in the Vatnajökull National Park in Southeast Iceland and observations of glacier sites where the respondents' companies are operating. The results indicate that all entrepreneurs consider climate change to be a real phenomenon that affects their present daily operations, but they perceive these implications not as significant threats to their business. The interaction of operator's attributes of agency such as firsthand experiences, risk perceptions, and abilities to self-organize, with structural elements of the glacier destination system such as economic rationales and hazard reduction institutions, has shaped and consolidated operators' adaptation processes in the form of a wait-and-see strategy combined with ad hoc reactive adaptation measures and postponed or prevented proactive long-term adaptation strategies. [ABSTRACT FROM AUTHOR]

Norse colonization of North Atlantic islands in the 1st millennium of the Common Era led to drastic prehistoric environmental changes in these previously "pristine" landscapes. In Iceland, Norse settlement is associated with a rapid decline in birch trees and heightened soil erosion, yet the timing of Norse exploration in the North Atlantic coincided with large climate changes that also influenced Icelandic environments. To date, there are few records that disentangle climatic and human impacts on terrestrial ecosystems, and there has been very little work on the impacts of Norse arrival on Iceland's aquatic ecosystems. Here we use a high-resolution lake-sediment record from Vestra Gíslholtsvatn (VGHV), southwest Iceland to investigate these processes during the last 2,000 years. Norse arrival (c. 870 CE) in Iceland is followed by a rapid increase in sedimentation rate and a transition in leaf wax n-alkanes indicating a decrease in trees and expansion of grasses. This transition coincides with limnological changes, including increased primary productivity (i.e. C17n-alkane and biogenic opal fluxes) and shifts in the haptophyte algal community. Many of these changes are still apparent today. Comparisons with a new winter-spring alkenone temperature reconstruction from VGHV and marine sea surface temperature records show little to no correlation between terrestrial and aquatic ecological changes and climate at this time. Similarly, volcanic eruptions recorded in VGHV are not associated with any long-term environmental changes. Rather, the VGHV record suggests that human settlement had a lasting impact on the catchment area of VGHV and changes within the lake ecosystem. [ABSTRACT FROM AUTHOR]

• Two new high-latitude CPR transects in the Northeast Atlantic. • Two generations of C. finmarchius in Norwegian Sea's Atlantic water. • Strikingly late seasonal descent of C. finmarchicus in the Norwegian Sea. • Spatial differences in seasonality of C. helgolandicus in the northern North Sea. • Wide range of thermal niches among the Calanus congeners. This paper analyses spatial and seasonal patterns for near-surface abundances of four Calanus species in the Northeast Atlantic based on monthly Continuous Plankton Recorder (CPR) Survey data collected during 2008–2016. C. finmarchicus , C. helgolandicus , C. hyperboreus and C. glacialis represent different ecosystems, and water masses with differing oceanographic properties and origins. Hence, these are considered as indicator species in climate change studies. A southern transect between Norway and the United Kingdom represented the northern North Sea, a central transect crossed the Norwegian and Iceland Seas, while a northern transect between Norway and Svalbard crossed the entrance to the Barents Sea. C. finmarchicus was prevalent everywhere, while C. helgolandicus was mainly confined to the northern North Sea though also documented downstream in the Norwegian Sea as far north as the entrance to the Barents Sea. The ratio of C. helgolandicus to C. finmarchicus abundances is expected to increase in the northern North Sea and southern Norwegian Sea given continued increases in seawater temperature. C. hyperboreus and C. glacialis were mainly associated with regions influenced by Arctic waters in the Iceland and Norwegian Seas, and south of Svalbard, respectively. Within Atlantic water masses in the central Norwegian Sea, a distinct second generation of C. finmarchicus with surprisingly high late-autumn concentrations of older stages were found. In Coastal water, two or more generations of C. finmarchicus occurred, while only one generation was evident in Arctic waters. Young C. finmarchicus of the first annual generation showed an earlier timing in Coastal than Atlantic and Arctic waters. The upper range of the temperature niche for both C. hyperboreus and C. glacialis was found to be around 7 °C. However, the peak occurrence within the study area was in 1–2 °C in Arctic water in the Iceland Sea in April for C. hyperboreus , while around 5 °C in Barents Sea Arctic water in July for C. glacialis. C. finmarchicus was present in all water masses with a peak occurrence in June at around 6 °C. C. finmarchicus generally dominated the Calanus -biomass, but C. hyperboreus in Arctic water in the Iceland and Norwegian Seas in spring, and C. helgolandicus in the northern North Sea, could match or exceed the biomass of C. finmarchicus. [ABSTRACT FROM AUTHOR]

The direct response of the cold-season atmospheric circulation to the Arctic sea ice loss is estimated from observed sea ice concentration (SIC) and an atmospheric reanalysis, assuming that the atmospheric response to the long-term sea ice loss is the same as that to interannual pan-Arctic SIC fluctuations with identical spatial patterns. No large-scale relationship with previous interannual SIC fluctuations is found in October and November, but a negative North Atlantic Oscillation (NAO)/Arctic Oscillation follows the pan-Arctic SIC fluctuations from December to March. The signal is field significant in the stratosphere in December, and in the troposphere and tropopause thereafter. However, multiple regressions indicate that the stratospheric December signal is largely due to concomitant Siberian snow-cover anomalies. On the other hand, the tropospheric January–March NAO signals can be unambiguously attributed to SIC variability, with an Iceland high approaching 45 m at 500 hPa, a 2°C surface air warming in northeastern Canada, and a modulation of blocking activity in the North Atlantic sector. In March, a 1°C northern Europe cooling is also attributed to SIC. An SIC impact on the warm Arctic–cold Eurasia pattern is only found in February in relation to January SIC. Extrapolating the most robust results suggests that, in the absence of other forcings, the SIC loss between 1979 and 2016 would have induced a 2°–3°C decade−1 winter warming in northeastern North America and a 40–60 m decade−1 increase in the height of the Iceland high, if linearity and perpetual winter conditions could be assumed. [ABSTRACT FROM AUTHOR]

Climate warming is predicted to alter routing and flows of energy through food webs because of the critical and varied effects of temperature on physiological rates, community structure, and trophic dynamics. Few studies, however, have experimentally assessed the net effect of warming on energy flux and food web dynamics in natural intact communities. Here, we test how warming affects energy flux and the trophic basis of production in a natural invertebrate food web by experimentally heating a stream reach in southwest Iceland by ~4°C for 2 yr and comparing its response to an unheated reference stream. Previous results from this experiment showed that warming led to shifts in the structure of the invertebrate assemblage, with estimated increases in total metabolic demand but no change in annual secondary production. We hypothesized that elevated metabolic demand and invariant secondary production would combine to increase total consumption of organic matter in the food web, if diet composition did not change appreciably with warming. Dietary composition of primary consumers indeed varied little between streams and among years, with gut contents primarily consisting of diatoms (72.9%) and amorphous detritus (19.5%). Diatoms dominated the trophic basis of production of primary consumers in both study streams, contributing 79–86% to secondary production. Although warming increased the flux of filamentous algae within the food web, total resource consumption did not increase as predicted. The neutral net effect of warming on total energy flow through the food web was a result of taxon‐level variation in responses to warming, a neutral effect on total invertebrate production, and strong trophic redundancy within the invertebrate assemblage. Thus, food webs characterized by a high degree of trophic redundancy may be more resistant to the effects of climate warming than those with more diverse and specialized consumers. [ABSTRACT FROM AUTHOR]