Contextualising Arctic warming and sea ice loss requires high-resolution climate proxy archives, which are rare across the high-northern latitudes. Here, we present annually resolved and absolutely dated tree-ring width measurements of living and dry juniper (Juniperus communis) shrubs, as well as herbarium specimens, all from southern Greenland. We develop a continuous chronology for 1526-2023 CE that correlates at 0.67 with mean June‒August temperatures (p < 0.001). We then identify reduced cell wall lignification (i.e., "Blue Rings") during exceptionally cold summers that often occurred after large volcanic eruptions, with Laki in 1783 and Tambora in 1815 CE causing the strongest responses. Our findings at the interface of dendroclimatology and wood anatomy provide a high-resolution paleoclimate record for southern Greenland that places anthropogenic warming in the context of natural climate variability.

Department of Geography Faculty of Science Masaryk University 613 00 Brno Czech Republic

Department of Geography University of Cambridge Cambridge CB2 3EN UK

Global Change Research Institute Czech Academy of Sciences 603 00 Brno Czech Republic

Institute of Earth Sciences Faculty of Natural Sciences University of Silesia in Katowice Sosnowiec Poland

Institute of Geography and Regional Development University of Wroclaw Wroclaw Poland

Natural History Museum Copenhagen Denmark

Zobrazit více v PubMed

Rantanen, M. et al. The Arctic has warmed nearly four times faster than the globe since 1979. DOI

Wunderling, N. et al. Global warming due to loss of large ice masses and Arctic summer sea ice. PubMed DOI PMC

Zhou, W., Leung, L. R. & Lu, J. Steady threefold Arctic amplification of externally forced warming masked by natural variability. DOI

Büntgen, U. & Esper, J. The need for high-resolution paleoclimate research. DOI

Masson-Delmotte, V. et al. Greenland climate change: from the past to the future. DOI

Gkinis, V. et al. A 120,000-year long climate record from a NW-Greenland deep ice core at ultra-high resolution. PubMed DOI PMC

Masson-Delmotte, V. et al. Past temperature reconstructions from deep ice cores: Relevance for future climate change.

Hammer, C. U., Clausen, H. B. & Dansgaard, W. Greenland ice sheet evidence of post-glacial volcanism and its climatic impact. DOI

Abbott, P. M. & Davies, S. M. Volcanism and the Greenland ice-cores: the tephra record. DOI

Sigl, M. et al. Timing and climate forcing of volcanic eruptions for the past 2500 years. PubMed DOI

Axford, Y. S. et al. Holocene temperature history at the western Greenland ice sheet margin reconstructed from lake sediments. DOI

Lasher, G. E., Axford, Y., Masterson, A. L., Berman, K. & Larocca, L. J. Holocene temperature and landscape history of southwest Greenland inferred from isotope and geochemical lake sediment proxies. DOI

Lusas, A. R. et al. Holocene climate and environmental history of East Greenland inferred from lake sediments. DOI

Anderson, N. J. et al. Landscape-Scale Variability of Organic Carbon Burial by SW Greenland Lakes. DOI

LaMarche, V. C. Jr Tree-ring evidence of past climatic variability. DOI

Jørgensen, R. H. et al. Growth response to climatic change over 120 years for DOI

Hollesen, J. et al. Winter warming as an important co-driver for Betula nana growth in western Greenland during the past century. PubMed DOI PMC

Lehejček, J., Buras, A., Svoboda, M. & Wilmking, M. Wood anatomy of DOI

Wilmking, M. et al. Influence of larval outbreaks on the climate reconstruction potential of an Arctic shrub. DOI

Prendin, A. L. et al. Influences of summer warming and nutrient availability on PubMed DOI PMC

Schmidt, N. M., Baittinger, C. & Forchhammer, M. C. Reconstructing century-long snow regimes using estimates of High Arctic DOI

Kuivinen, K. C. & Lawson, M. P. Dendroclimatic analysis of birch in South Greenland. DOI

Xu, C. et al. Oxygen Isotopes in Tree Rings from Greenland: A New Proxy of NAO. DOI

Piermattei, A. et al. A millennium-long ‘Blue Ring’ chronology from the Spanish Pyrenees reveals severe ephemeral summer cooling after volcanic eruptions. DOI

Tardif, J. C., Salzer, M. W., Conciatori, F., Bunn, A. G. & Hughes, M. K. Formation, structure and climatic significance of blue rings and frost rings in high elevation bristlecone pine ( DOI

Pellizzari, E., Pividori, M. & Carrer, M. Winter precipitation effect in a mid-latitude temperature-limited environment: the case of common juniper at high elevation in the Alps. DOI

Carrer, M., Dibona, R., Prendin, A. L. & Brunetti, M. Recent waning snowpack in the Alps is unprecedented in the last six centuries. DOI

Shumilov, O. I. et al. Paleoclimatic potential of the northernmost juniper trees in Europe. DOI

Hantemirov, R. M., Shiyatov, S. G. & Gorlanova, L. A. Dendroclimatic study of Siberian juniper. DOI

Opała-Owczarek, M. et al. Slow growing juniper shrubs from northern Iceland record summer temperature changes over the last 800 years. DOI

Lehejček, J., Roman, M., Lexa, M., Aspholm, P. E. & Masek, J. Old Juniper Troll stand – the oldest shrub population from Scandinavia. DOI

Carrer, M. et al. Common juniper, the oldest nonclonal woody species across the tundra biome and the European continent. PubMed DOI PMC

Buras, A. et al. Shrubs shed light on 20th century Greenland Ice Sheet melting. DOI

Meddelelser om Grønland undgvine af Commissionen for Ledelsen af de geologiske og geographiske Endersegelser i Grønland (Tolvte Hefte, København I Kommission Hos C.A. Reitzel, 1888).

Myers-Smith, I. et al. Climate sensitivity of shrub growth across the tundra biome. DOI

Hallinger, M., Manthey, M. & Wilmking, M. Establishing a missing link: warm summers and winter snow cover promote shrub expansion into alpine tundra in Scandinavia. PubMed DOI

Schmidt, N. M., Baittinger, C., Kollmann, J. & Forchhammer, M. C. Consistent dendrochronological response of the dioecious DOI

Gamm, C. M. et al. Declining growth of deciduous shrubs in the warming climate of continental western Greenland. DOI

Pedersen, R. A. & Christensen, J. H. Attributing greenland warming patterns to regional arctic sea ice loss. DOI

Zhang, Q. et al. Temporal and spatial variability in contemporary Greenland warming (1958–2020). DOI

Hanna, E. Greenland surface air temperature changes from 1981 to 2019 and implications for ice-sheet melt and mass-balance change. DOI

Hörhold, M. et al. Modern temperatures in central–north Greenland warmest in past millennium. PubMed DOI PMC

Kaufman, D. S. et al. Recent warming reverses long-term Arctic cooling. PubMed DOI

Kjær, K. H. et al. Glacier response to the Little Ice Age during the Neoglacial cooling in Greenland. DOI

Winsor, K., Carlson, A. E. & Rood, D. H. DOI

Vinther, B. M., Andersen, K. K., Jones, P. D., Briffa, K. R. & Cappelen, J. Extending Greenland temperature records into the late eighteenth century.

Millet, L. et al. Anthropogenic versus climatic control in a high-resolution 1500-year chironomid stratigraphy from a South Western Greenland lake. DOI

Miettinen, A., Divine, D. V., Husum, K., Koç, N. & Jennings, A. Exceptional ocean surface conditions on the SE Greenland shelf during the Medieval Climate Anomaly. DOI

Kobashi, T. et al. Persistent multi-decadal Greenland temperature fluctuation through the last millennium. DOI

McKay, N. P. & Kaufman, D. S. An extended Arctic proxy temperature database for the past 2000 years. PubMed DOI PMC

Gennaretti, F. et al. Bayesian multiproxy temperature reconstruction with black spruce ring widths and stable isotopes from the northern Quebec taiga. DOI

Anchukaitis, K. J. et al. Tree-ring-reconstructed summer temperatures from Northwestern North America during the last nine centuries. DOI

Kononov, Y. M., Friedrich, M. & Boettger, T. Regional Summer Temperature Reconstruction in the Khibiny Low Mountains (Kola Peninsula, NW Russia) by Means of Tree-ring Width during the Last Four Centuries. DOI

LaMarche, V. C. Jr & Hirschboeck, K. K. Frost rings in trees as records of major volcanic eruptions. DOI

Filion, L., Payette, S., Gauthier, L. & Boutin, Y. Light rings in subarctic conifers as a dendrochronological tool. DOI

Delwaide, A., Filion, L. & Payette, S. Spatiotemporal distribution of light rings in subarctic black spruce, Québec. DOI

Briffa, K. R., Jones, P. D., Schweingruber, F. H. & Osborn, T. J. Influence of volcanic eruptions on Northern Hemisphere summer temperature over the past 600 years. DOI

Hantemirov, R. M., Gorlanova, L. A. & Shiyatov, S. G. Extreme temperature events in summer in northwest Siberia since AD 742 inferred from tree rings. DOI

Körner, C., Lenz, A. & Hoch, G. Chronic in situ tissue cooling does not reduce lignification at the Swiss treeline but enhances the risk of ‘blue’ frost rings. PubMed DOI PMC

Thordarson, T. & Self, S. Atmospheric and environmental effects of the 1783–1784 Laki eruption: A review and reassessment. DOI

van Swinden, S. P.

Hammer, C. U. Traces of Icelandic eruptions in the Greenland ice sheet. DOI

Jacoby, G. C., Workman, K. W. & D’Arrigo, R. D. Laki eruption of 1783, tree rings, and disaster for northwest Alaska Inuit. DOI

Edwards, J. et al. Intra-annual climate anomalies in northwestern North America following the 1783–1784 CE Laki eruption. DOI

Jones, P. D., Briffa, K. R. & Schweingruber, F. H. Tree-ring evidence of the widespread effects of explosive volcanic eruptions. DOI

Büntgen, U. et al. Global wood anatomical perspective on the onset of the Late Antique Little Ice Age (LALIA) in the mid-6th century CE. PubMed DOI

Feilberg, J. A phytogeographical study of South Greenland. Vascular plants.

Lange, J. Bemærkninger om de af Expeditionerne i Aarene 1880-85 samlede Karplanter fra Vestkysten af Grønland. DOI

Kruuse, C. Rejser og botaniske undersøgelser i Østgrønland mellem 65°20’ og 67°20’ i aarene 1898-1902, samt Angmagssalik egnens vegetation.

Miller, H. J. Anatomical studies of DOI

Tumajer, J. et al. Growing faster, longer or both? Modelling plastic response of Juniperus communis growth phenology to climate change. DOI

Opała-Owczarek, M. & Owczarek, P. Herbarium records in Arctic dwarf shrub dendrochronology: Methodological approach and perspectives. DOI

Gärtner H. & Schweingruber F. H.

Bunn, A. G. A dendrochronology program library in R(dplR). DOI

Piermattei, A., Crivellaro, A., Carrer, M. & Urbinati, C. The “blue ring”: anatomy and formation hypothesis of a new tree-ring anomaly in conifers. DOI

Cappelen, J. & Vinther, B. M.

Cappelen, J.

Walsh, J. E., Fetterer, F., Scott Stewart, J. & Chapman, W. L. A database for depicting Arctic sea ice variations back to 1850. DOI

Connolly, R., Connolly, M. & Soon, W. Re-calibration of Arctic sea ice extent datasets using Arctic surface air temperature records. DOI

Zang, C. & Biondi, F. Treeclim: an R package for the numerical calibration of proxy-climate relationships. DOI

Lough, J. M. & Fritts, H. C. An assessment of the possible effects of volcanic eruptions on North American climate using tree-ring data, 1602 to 1900 AD. DOI

Bunn, A. G. et al. dplR. Dendrochronology Program Library in R. https://cran.r-project.org/web/packages/dplR/dplR.pdf (2025).

Andresen, C. S., Kokfelt, U. & Sicre, M. A. Exceptional 20th century glaciological regime of a major SE Greenland outlet glacier. PubMed DOI PMC

Hantemirov, R. M. et al. Current Siberian heating is unprecedented during the past seven millennia. PubMed DOI PMC

Macias Fauria, M. et al. Unprecedented low twentieth century winter sea-ice extent in the Western Nordic seas since A.D. 1200. DOI