| 1. |
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| 2. |
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| 3. |
- Büntgen, Ulf, et al.
(författare)
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Tree-Ring Amplification of the Early Nineteenth-Century Summer Cooling in Central Europe
- 2015
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Ingår i: Journal of Climate. - 0894-8755 .- 1520-0442. ; 28:13, s. 5272-5288
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Forskningsöversikt (refereegranskat)abstract
- Annually resolved and absolutely dated tree-ring chronologies are the most important proxy archives to reconstruct climate variability over centuries to millennia. However, the suitability of tree-ring chronologies to reflect the “true” spectral properties of past changes in temperature and hydroclimate has recently been debated. At issue is the accurate quantification of temperature differences between early nineteenth-century cooling and recent warming. In this regard, central Europe (CEU) offers the unique opportunity to compare evidence from instrumental measurements, paleomodel simulations, and proxy reconstructions covering both the exceptionally hot summer of 2003 and the year without summer in 1816. This study uses 565 Swiss stone pine (Pinus cembra) ring width samples from high-elevation sites in the Slovakian Tatra Mountains and Austrian Alps to reconstruct CEU summer temperatures over the past three centuries. This new temperature history is compared to different sets of instrumental measurements and state-of-the-art climate model simulations. All records independently reveal the coolest conditions in the 1810s and warmest after 1996, but the ring width–based reconstruction overestimates the intensity and duration of the early nineteenth-century summer cooling by approximately 1.5°C at decadal scales. This proxy-specific deviation is most likely triggered by inflated biological memory in response to reduced warm season temperature, together with changes in radiation and precipitation following the Tambora eruption in April 1815. While suggesting there exists a specific limitation in ring width chronologies to capture abrupt climate perturbations with increased climate system inertia, the results underline the importance of alternative dendrochronological and wood anatomical parameters, including stable isotopes and maximum density, to assess the frequency and severity of climatic extremes.
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| 4. |
- Charpentier Ljungqvist, Fredrik, 1982-
(författare)
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Den långa medeltiden : Den nordiska ländernas historia från folkvandringstid till reformation
- 2015
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Medeltidshistorikern Fredrik Charpentier Ljungqvist bjuder på en lättläst exposé över den politiska, ekonomiska, sociala och kulturella utvecklingen i Norden under tusen år med utgångspunkt i de senaste rönen från arkeologisk och historisk forskning. Den långa medeltiden är en introduktion till Nordens historia från folkvandringstiden på 500-talet fram till reformationen på 1500-talet. Till skillnad från tidigare översiktsverk behandlas här hela Norden, och inte bara ett enskilt nordiskt land, och den traditionella uppdelningen mellan medeltid och forntid överges.Ett av kapitlen skildrar den politiska utvecklingen, men i övrigt står de sociala förhållandena i centrum i denna översikt. Hur bodde man och vad åt man? Vilka möjligheter fanns det att resa och hur utvecklades skeppsbyggnadskonsten? När skedde klimatförändringar och hur påverkade de människor? Vilka redskap användes i jordbruket, för hantverk och för att bygga hus och skepp? I vilken grad levde människor av självförsörjning och hur utvecklad var handeln? Hur såg lag och rätt ut?I boken behandlas allt från framväxten av nordiska kungariken och städer till jordbrukets och konsthantverkets utveckling och människors hälsa under forna tider. Vi får bekanta oss med livet för såväl kungar som trälar och följa med genom sociala omvälvningar som kristnandet, digerdöden och ståndssamhällets framväxt. Geografiskt rör vi oss från den karga nordnorska kusten i norr till den bördiga danska myllan i söder, med avstickare till Island och Grönland och med vikingafärder i öster- och västerled.
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| 5. |
- Charpentier Ljungqvist, Fredrik, 1982-
(författare)
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Forntidens klimat en nyckel
- 2018
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Ingår i: Sveriges natur: Svenska naturskyddsföreningens tidskrift. - 0039-6974. ; 4
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Forskningsöversikt (populärvet., debatt m.m.)
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| 6. |
- Charpentier Ljungqvist, Fredrik, 1982-
(författare)
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Hedniskt motstånd i Svealand under sent 1000-tal
- 2018
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Ingår i: Historisk Tidskrift. - 0345-469X .- 2002-4827. ; 138:2, s. 197-226
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Tidskriftsartikel (refereegranskat)abstract
- I denna artikel studeras beläggen, och sannolikheten, för existensen av en hednisk revolt i Svealand vid slutet av 1000-talet. En sådan, ledd av upprorskungen BlotSven, är skildrad i högmedeltida svenska och isländska källor, men dess historicitet har ifrågasatts under senare år. I artikeln studeras såväl samtida och senare skriftliga källor som den arkeologiska evidensen till religionsförhållandena i Svealand runt år 1100. Samtliga källtyper stödjer uppfattningen att det fortfarande existerade ett motstånd mot kristendomen. En jämförelse av den högmedeltida traditionen om Blot-Svens revolt med de bättre dokumenterade, ungefär samtida, hedniska revolterna i andra nykristnade områden i Europa visar vidare att den följer samma mönster och därmed framstår som mer trovärdig.
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| 7. |
- Charpentier Ljungqvist, Fredrik, 1982-, et al.
(författare)
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Histoire du climat du Royaume de Suède à l’époque modern : [Climate hisotry of the early modern Swedish Realm]
- 2018
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Ingår i: Revue d’Histoire Nordique. - 1778-9605. ; 27, s. 201-226
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In this article, we assess the scholarship of climate history in the former Swedish Realm (roughly, present-day Sweden, Finland, and Estonia) during the early modern period. Climate history research has primarily focused on consequences of climate change and variability on human history, but also on producing documentary-based reconstructions of past climate. Recent advances in palaeo-climatology, in particular dendroclimatology, during the past two to three decades, have made it possible to study climate impacts on early modern history. However, while the field of climate history has developed substantially in much of Europe, it remains rather underdeveloped and has drawn limited intetest in the Nordic countries. Apart from some recent studies for Finland, the climate history of the former Swedish Realm falls short of the standards of the field in contemporary European scholarship. Existing scholarship has nevertheless demonstrated the link between cold springs and summers and poor harvests, particuiar in Finland, but few studies have assessed the effects of climate on society outside of periods of severe food shortage or famines. The article concludes with outlines and reflections for future scholarship in climate history of the early modern Swedish Realm.
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| 8. |
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| 9. |
- Charpentier Ljungqvist, Fredrik, 1982-
(författare)
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Human and societal dimensions of past climate change
- 2017
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Ingår i: Issues and Concepts in Historical Ecology. - Cambridge : Cambridge University Press. - 9781108420983 - 9781108355780 ; , s. 41-83
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Bokkapitel (refereegranskat)
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| 10. |
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| 11. |
- Charpentier Ljungqvist, Fredrik, 1982-
(författare)
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Klimatet i backspegeln
- 2016
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Ingår i: Gaudeamus. - 0016-5247. ; :3, s. 12-13
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 12. |
- Charpentier Ljungqvist, Fredrik, 1982-
(författare)
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Klimatet och människan under 12 000 år
- 2017
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- I boken presenteras för första gången på svenska resultaten från den senaste klimathistoriska forskningen för en bred publik. I en välblandad mix av historia och klimatvetenskap får läsaren följa med på en medryckande resa genom världshistorien då kraftiga och plötsliga klimatförändringar emellanåt dramatiskt förändrat livsvillkoren för miljoner människor.För 6 000 år sedan var till exempel Sahara en frodig savann i stället för världens största öken, samtidigt som klimatet var varmt nog i Sverige för sköldpaddor och vilda vindruvor. Senare under historien har stora variationer i monsunregnen i Asien gett upphov till antingen välstånd eller hungersnöd för miljontals människor.För tusen år sedan kollapsade indianska civilisationer av torka, samtidigt som ett varmare klimat tillät nordbor att kolonisera södra Grönland. Den så kallade lilla istiden, som kulminerade på 1600-talet, orsakade försörjningskriser i Europa och Kina och på många andra håll i världen.Författaren ger oss åtskilliga spännande och lärorika exempel på hur klimatförändringar under historien påverkat utvecklingen i olika delar av världen och hur människor hanterat eller inte hanterat konsekvenserna av klimatförändringar. Det är insikter som är mycket relevanta i vår tid.
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| 13. |
- Charpentier Ljungqvist, Fredrik, 1982-
(författare)
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Lagfäst kungamakt under högmedeltiden : en komparativ internnordisk studie
- 2016
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Bok (refereegranskat)abstract
- Denna bok behandlar lagregleringen av den expanderande kungamakten i det högmedeltida Danmark, Norge och Sverige ur ett komparativt perspektiv. Utifrån bevarat lagmaterial undersöks utvecklingen av kungamaktens rättsliga och militära befogenheter och funktioner i relation till tingsmenigheternas och kyrkans förändrade maktställning. Dessa statsrättsliga frågeställningar, som ägnats förhållandevis lite intresse under senare år, blir belysta utifrån den numera omfattande internationella forskningen om den medeltida statsbildningsprocessen i Europa. Såväl danskt, norskt som svenskt lagmaterial ger uttryck för en påtaglig ökning av samhälleliga funktioner underställda en allt starkare kungamakt. Likväl framträder samtidigt betydande internordiska skillnader avseende såväl omfattningen av, som formerna för, den kungliga maktutövningen. Den lagreglerade kungamakten var, i de flesta avseenden, starkast och tidigast utvecklad i Norge och svagast och senast utvecklad i Sverige. Studien visar att den allt mer centraliserade och institutionaliserade kungliga maktutövningen, som präglades av en ökad ensamrätt till bruket av legitimt våld, kan betraktas som uttryck för en pågående statsbildningsprocess. Lagregleringen av rättslig makt framstår som avsevärt viktigare för denna utveckling än regleringen av militär eller fiskal makt. Ett annat viktigt resultat är att kunglig exekutiv makt först uppträdde efter etableringen av dömande, och i många avseenden även lagstiftande, kunglig makt.
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| 14. |
- Charpentier Ljungqvist, Fredrik, 1982-, et al.
(författare)
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Northern Hemisphere hydroclimate variability over the past twelve centuries
- 2016
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 532:7597, s. 94-98
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Tidskriftsartikel (refereegranskat)abstract
- Accurate modelling and prediction of the local to continental-scale hydroclimate response to global warming is essential given the strong impact of hydroclimate on ecosystem functioning, crop yields, water resources, and economic security. However, uncertainty in hydroclimate projections remains large, in part due to the short length of instrumental measurements available with which to assess climate models. Here we present a spatial reconstruction of hydroclimate variability over the past twelve centuries across the Northern Hemisphere derived from a network of 196 at least millennium-long proxy records. We use this reconstruction to place recent hydrological changes and future precipitation scenarios in a long-term context of spatially resolved and temporally persistent hydroclimate patterns. We find a larger percentage of land area with relatively wetter conditions in the ninth to eleventh and the twentieth centuries, whereas drier conditions are more widespread between the twelfth and nineteenth centuries. Our reconstruction reveals that prominent seesaw patterns of alternating moisture regimes observed in instrumental data across the Mediterranean, western USA, and China have operated consistently over the past twelve centuries. Using an updated compilation of 128 temperature proxy records, we assess the relationship between the reconstructed centennial-scale Northern Hemisphere hydroclimate and temperature variability. Even though dry and wet conditions occurred over extensive areas under both warm and cold climate regimes, a statistically significant co-variability of hydroclimate and temperature is evident for particular regions. We compare the reconstructed hydroclimate anomalies with coupled atmosphere-ocean general circulation model simulations and find reasonable agreement during pre-industrial times. However, the intensification of the twentieth-century-mean hydroclimate anomalies in the simulations, as compared to previous centuries, is not supported by our new multi-proxy reconstruction. This finding suggests that much work remains before we can model hydroclimate variability accurately, and highlights the importance of using palaeoclimate data to place recent and predicted hydroclimate changes in a millennium-long context.
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| 15. |
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| 16. |
- Charpentier Ljungqvist, Fredrik, 1982-
(författare)
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Rape in the Icelandic Sagas : An Insight in the Perceptions about Sexual Assaults on Women in the Old Norse World
- 2015
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Ingår i: Journal of Family History. - : SAGE Publications. - 0363-1990 .- 1552-5473. ; 40:4, s. 431-447
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Tidskriftsartikel (refereegranskat)abstract
- This article examines the perceptions of rape and other sexual assaults against women in the Old Norse world based on the medieval Icelandic saga literature. A key starting point is the fact that the Old Norse society was an honor culture, in which honor and dishonor were concepts of supreme social importance. The Icelandic saga literature devotes very little attention to women’s own experiences of sexual assault or to how such assault affected their personal honor, despite clear indications that rape was perceived as a violation of a woman’s bodily integrity and was dishonorable to the victim. Conversely, the central theme in the depictions of rape in the saga literature is that sexual assault was regarded as highly defamatory to the woman’s male relatives, demanding blood vengeance in return. Thus, rape was considered primarily an offense against the woman’s male relatives and only secondly against the woman herself. Since sexual assaults against women could be used to dishonor men, it follows that there are examples in the sagas of how rape is used as a “weapon” during feuds. It is quite clear, however, that this was regarded as a feud crime, and rape, in most cases, was socially unacceptable and denounced.
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| 17. |
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| 18. |
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| 19. |
- Charpentier Ljungqvist, Fredrik, 1982-, et al.
(författare)
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The spatiotemporal distribution of Late Viking Age Swedish runestones : A reflection of the Christianisation process and its speed
- 2018
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Ingår i: Journal of Archaeological Science. - : Elsevier BV. - 2352-409X .- 2352-4103. ; 21, s. 849-861
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Tidskriftsartikel (refereegranskat)abstract
- The Late Viking Age Swedish runestones are commonly acknowledged as early Christian monuments. Using geostatistical techniques and descriptive statistics, we systematically investigate the regional-to-local spatiotemporal patterns of 1302 ornamentally dated Swedish runestones regarding the timing and speed of the Christianisation process. After quantitative geostatistical analyses of the age distribution patterns of Swedish runestones, we evaluate whether the observed patterns correspond to the pace and pattern of Christianisation, as represented by the presence of mission bishoprics, early church sites, late pagan grave sites and royal estates. We identify seven distinct age groups of runestones and statistically significant regional-to-local spatiotemporal differences in the age and age spread of runestones. The oldest runestones, with the smallest age spread, are found in south-western medieval Sweden, and the youngest, as well as the largest age spread, in the north-east, respectively. We find that runestones are significantly older close to early ecclesiastical sites, regardless of the analytical level, and significantly younger near to late pagan graves. The results obtained are inconclusive as to whether runestones are older near royal estates. Our results support that the spatiotemporal patterns of runestone sites mirror the timing of the Christianisation process and that geostatistical approaches to larger archaeological or historical data sets can add new dimensions to the understanding of the spatial dimensions of past societal changes.
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| 20. |
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| 21. |
- Esper, Jan, et al.
(författare)
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Ranking of tree-ring based temperature reconstructions of the past millennium
- 2016
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Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 145, s. 134-151
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Tidskriftsartikel (refereegranskat)abstract
- Tree-ring chronologies are widely used to reconstruct high-to low-frequency variations in growing season temperatures over centuries to millennia. The relevance of these timeseries in large-scale climate reconstructions is often determined by the strength of their correlation against instrumental temperature data. However, this single criterion ignores several important quantitative and qualitative characteristics of tree-ring chronologies. Those characteristics are (i) data homogeneity, (ii) sample replication, (iii) growth coherence, (iv) chronology development, and (v) climate signal including the correlation with instrumental data. Based on these 5 characteristics, a reconstruction-scoring scheme is proposed and applied to 39 published, millennial-length temperature reconstructions from Asia, Europe, North America, and the Southern Hemisphere. Results reveal no reconstruction scores highest in every category and each has their own strengths and weaknesses. Reconstructions that perform better overall include N-Scan and Finland from Europe, E-Canada from North America, Yamal and Dzhelo from Asia. Reconstructions performing less well include W-Himalaya and Karakorum from Asia, Tatra and S-Finland from Europe, and Great Basin from North America. By providing a comprehensive set of criteria to evaluate tree-ring chronologies we hope to improve the development of large-scale temperature reconstructions spanning the past millennium. All reconstructions and their corresponding scores are provided at www.blogs.uni-mainz.de/fb09climatology.
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| 22. |
- Hellmann, Lena, et al.
(författare)
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Diverse growth trends and climate responses across Eurasia's boreal forest
- 2016
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 11:7
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Tidskriftsartikel (refereegranskat)abstract
- The area covered by boreal forests accounts for similar to 16% of the global and 22% of the Northern Hemisphere landmass. Changes in the productivity and functioning of this circumpolar biome not only have strong effects on species composition and diversity at regional to larger scales, but also on the Earth's carbon cycle. Although temporal inconsistency in the response of tree growth to temperature has been reported from some locations at the higher northern latitudes, a systematic dendroecological network assessment is still missing for most of the boreal zone. Here, we analyze the geographical patterns of changes in summer temperature and precipitation across northern Eurasia >60 degrees N since 1951 AD, as well as the growth trends and climate responses of 445 Pinus, Larix and Picea ring width chronologies in the same area and period. In contrast to widespread summer warming, fluctuations in precipitation and tree growth are spatially more diverse and overall less distinct. Although the influence of summer temperature on ring formation is increasing with latitude and distinct moisture effects are restricted to a few southern locations, growth sensitivity to June-July temperature variability is only significant at 16.6% of all sites (p <= 0.01). By revealing complex climate constraints on the productivity of Eurasia's northern forests, our results question the a priori suitability of boreal tree-ring width chronologies for reconstructing summer temperatures. This study further emphasizes regional climate differences and their role on the dynamics of boreal ecosystems, and also underlines the importance of free data access to facilitate the compilation and evaluation of massively replicated and updated dendroecological networks.
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| 23. |
- Luterbacher, J., et al.
(författare)
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European summer temperatures since Roman times
- 2016
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 11:2
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Tidskriftsartikel (refereegranskat)abstract
- The spatial context is criticalwhen assessing present-day climate anomalies, attributing them to potential forcings and making statements regarding their frequency and severity in a long-term perspective. Recent international initiatives have expanded the number of high-quality proxy-records and developed new statistical reconstruction methods. These advances allow more rigorous regional past temperature reconstructions and, in turn, the possibility of evaluating climate models on policy-relevant, spatiotemporal scales. Here we provide a new proxy-based, annually-resolved, spatial reconstruction of the European summer (June-August) temperature fields back to 755 CE based on Bayesian hierarchical modelling (BHM), together with estimates of the European mean temperature variation since 138 BCE based on BHM and composite-plus-scaling (CPS). Our reconstructions compare well with independent instrumental and proxy-based temperature estimates, but suggest a larger amplitude in summer temperature variability than previously reported. Both CPS and BHM reconstructions indicate that the mean 20th century European summer temperature was not significantly different from some earlier centuries, including the 1st, 2nd, 8th and 10th centuries CE. The 1st century (in BHM also the 10th century) may even have been slightly warmer than the 20th century, but the difference is not statistically significant. Comparing each 50 yr period with the 1951-2000 period reveals a similar pattern. Recent summers, however, have been unusually warm in the context of the last two millennia and there are no 30 yr periods in either reconstruction that exceed the mean average European summer temperature of the last 3 decades (1986-2015 CE). A comparison with an ensemble of climate model simulations suggests that the reconstructed European summer temperature variability over the period 850-2000 CE reflects changes in both internal variability and external forcing on multi-decadal time-scales. For pan-European temperatures we find slightly better agreement between the reconstruction and the model simulations with high-end estimates for total solar irradiance. Temperature differences between the medieval period, the recent period and the Little Ice Age are larger in the reconstructions than the simulations. This may indicate inflated variability of the reconstructions, a lack of sensitivity and processes to changes in external forcing on the simulated European climate and/or an underestimation of internal variability on centennial and longer time scales.
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| 24. |
- Shi, Feng, et al.
(författare)
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A multi-proxy reconstruction of spatial and temporal variations in Asian summer temperatures over the last millennium
- 2015
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Ingår i: Climatic Change. - : Springer Science and Business Media LLC. - 0165-0009 .- 1573-1480. ; 131:4, s. 663-674
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Tidskriftsartikel (refereegranskat)abstract
- To investigate climate variability in Asia during the last millennium, the spatial and temporal evolution of summer (June–July–August; JJA) temperature in eastern and south-central Asia is reconstructed using multi-proxy records and the regularized expectation maximization (RegEM) algorithm with truncated total least squares (TTLS), under a point-by-point regression (PPR) framework. The temperature index reconstructions show that the late 20th century was the warmest period in Asia over the past millennium. The temperature field reconstructions illustrate that temperatures in central, eastern, and southern China during the 11th and 13th centuries, and in western Asia during the 12th century, were significantly higher than those in other regions, and comparable to levels in the 20th century. Except for the most recent warming, all identified warm events showed distinct regional expressions and none were uniform over the entire reconstruction area. The main finding of the study is that spatial temperature patterns have, on centennial time-scales, varied greatly over the last millennium. Moreover, seven climate model simulations, from the Coupled Model Intercomparison Project Phase 5 (CMIP5), over the same region of Asia, are all consistent with the temperature index reconstruction at the 99 % confidence level. Only spatial temperature patterns extracted as the first empirical orthogonal function (EOF) from the GISS-E2-R and MPI-ESM-P model simulations are significant and consistent with the temperature field reconstruction over the past millennium in Asia at the 90 % confidence level. This indicates that both the reconstruction and the simulations depict the temporal climate variability well over the past millennium. However, the spatial simulation or reconstruction capability of climate variability over the past millennium could be still limited. For reconstruction, some grid points do not pass validation tests and reveal the need for more proxies with high temporal resolution, accurate dating, and sensitive temperature signals, especially in central Asia and before AD 1400.
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| 25. |
- Taricco, Carla, et al.
(författare)
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Multispectral analysis of Northern Hemisphere temperature records over the last five millennia
- 2015
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Ingår i: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 45:1-2, s. 83-104
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Tidskriftsartikel (refereegranskat)abstract
- Aiming to describe spatio-temporal climate variability on decadal-to-centennial time scales and longer, we analyzed a data set of 26 proxy records extending back 1,000–5,000 years; all records chosen were calibrated to yield temperatures. The seven irregularly sampled series in the data set were interpolated to a regular grid by optimized methods and then two advanced spectral methods—namely singular-spectrum analysis (SSA) and the continuous wavelet transform—were applied to individual series to separate significant oscillations from the high noise background. This univariate analysis identified several common periods across many of the 26 proxy records: a millennial trend, as well as oscillations of about 100 and 200 years, and a broad peak in the 40–70-year band. To study common NH oscillations, we then applied Multichannel SSA. Temperature variations on time scales longer than 600 years appear in our analysis as a dominant trend component, which shows climate features consistent with the Medieval Warm Period and the Little Ice Age. Statistically significant NH-wide peaks appear at 330, 250 and 110 years, as well as in a broad 50–80-year band. Strong variability centers in several bands are located around the North Atlantic basin and are in phase opposition between Greenland and Western Europe.
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