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Surging outlet glaciers are important in draining large ice caps, but the mechanisms controlling surge periodicities are poorly known. We investigated a sediment sequence from the glacier-fed Lake Logurinn in eastern Iceland, and our unique annually resolved data, based on sedimentary varves, imply that Eyjabakkajokull, an outlet glacier of Vatnajokull, began surging about 2200 cal a BP (before 19

Tree phenology has been recognized as an important indicator of climate change, and a wide range of budburst models have been developed. The models differ in temperature sensitivity, and the choice of model can therefore influence the result of climate impact assessments. In this study we compared the ability of 15 models to simulate budburst of the main forest tree species in Sweden. Records on t

Climate warming in the Swedish sub-Arctic since 2000 has reached a level at which statistical analysis shows for the first time that current warming has exceeded that in the late 1930' s and early 1940' s, and has significantly crossed the 0 degrees C mean annual temperature threshold which causes many cryospheric and ecological impacts. The accelerating temperature increase trend has driven simil

Popular Abstract in Swedish Ett ökade förbrukningen av fossila bränslen kommer att accelerera den globala uppvärmningen med oöverskådlig inverkan på oss och vår miljö. Utvecklingen av alternativa, förnybara och miljömässigt rena energiformer är därför helt essentiell. En möjlig lösning är att skapa artificiell fotosyntes, där solenergi omvandlas till bränsle (till exempel vätgas) i en process där A continuing use of fossil fuels will accelerate global warning and result in severe consequences for the environment and thereby also us. Development of alternative, sustainable and environmentally friendly energy sources is therefore crucial. One approach is to create an artificial photosynthetic system that converts sunshine into fuel (e.g. hydrogen gas) by splitting water molecules. However, i

Properties of varved sediments from Lake Logurinn in eastern Iceland and their link to climate and glacial processes of Eyjabakkajokull, an outlet glacier of the Vatnajokull icecap, were examined. A varve chronology, which covers the period AD 1262-2005, was constructed from visual observations, high-resolution images, X-ray density and geochemical properties determined from X-radiography and X-ra

The development since the beginning of the 20th century of the pollen-analytical theory and method as a palaeoecological tool for describing landscape development is outlined with reference to southern Scandinavia. Numerical methods applied since the 1980s are discussed. The aim of this paper is to provide a new perspective on the landscape development and human impact during the Holocene by apply

In this study, a reconstruction of the long-term development and lateral expansion of a south Swedish peat bog was performed using a multi-proxy approach, including dendrochronology, peat stratigraphy and macrofossil and pollen analyses. By combining mapping of cross-dated subfossil trees with radiocarbon-dated peat sequences, an improved approach to reconstruction of lateral peat expansion was ap

This study aims to evaluate the direct effects of anthropogenic deforestation on simulated climate at two contrasting periods in the Holocene, similar to 6 and similar to 0.2 k BP in Europe. We apply We apply the Rossby Centre regional climate model RCA3, a regional climate model with 50 km spatial resolution, for both time periods, considering three alternative descriptions of the past vegetation

The major objectives of this paper are: (1) to review the pros and cons of the scenarios of past anthropogenic land cover change (ALCC) developed during the last ten years, (2) to discuss issues related to pollen-based reconstruction of the past land-cover and introduce a new method, REVEALS (Regional Estimates of VEgetation Abundance from Large Sites), to infer long-term records of past land-cove

Photosynthesis is highly responsive to environmental and physiological variables, including phenology, foliage nitrogen (N) content, atmospheric CO2 concentration ([CO2]), irradiation (Q), air temperature (T) and vapour pressure deficit (D). Each of these responses is likely to be modified by long-term changes in climatic conditions such as rising air temperature and [CO2]. When modelling photosyn

We present pollen-based reconstructions of the spatio-temporal dynamics of northern European regional vegetation abundance through the Holocene. We apply the Regional Estimates of VEgetation Abundance from Large Sites (REVEALS) model using fossil pollen records from eighteen sites within five modern biomes in the region. The eighteen sites are classified into four time-trajectory types on the basi

This article gives an overview of the studies on the environment surrounding the Abisko Scientific Research Station in Swedish Lapland. The long-term monitoring of the Station on processes related to the climate, and to the physical, biotic, and chemical environmental conditions is particularly addressed. Some variables are recorded since more than 100 years. The obtained data in combination with

We present quantitative reconstructions of regional vegetation cover in north-western Europe, western Europe north of the Alps, and eastern Europe for five time windows in the Holocene [around 6k, 3k, 0.5k, 0.2k, and 0.05k calendar years before present (bp)] at a 1 degrees x1 degrees spatial scale with the objective of producing vegetation descriptions suitable for climate modelling. The REVEALS m

Climate change and thawing of permafrost will likely result in increased decomposition of terrestrial organic carbon and subsequent carbon emissions to the atmosphere from terrestrial and aquatic systems. The quantitative importance of mineralization of terrestrial organic carbon in lakes in relation to terrestrial carbon fluxes is poorly understood and a serious drawback for the understanding of

Although satellite-based sensors have made vegetation data series available for several decades, the detection of vegetation trend and change is not yet straightforward. This is partly due to the scarcity of available change detection algorithms suitable for identifying and characterizing both abrupt and non-abrupt changes, without sacrificing accuracy or computational speed. We propose a user-fri

Since the mid 1960s sugar planters in Thailand have formed some of the strongest farmers associations in Asia. Organising practically all sugar planters, these associations have over the years successfully negotiated with sugar mill owners and with the state. They have achieved a system of revenue sharing in the cane and sugar industry which protects them from the vagaries of fluctuations in world