Ole Humlum

• Humlum, Ole; Christiansen, Hanne H; Mortensen, Lis E.; Stuart, Finlay M. & Stone, John O. (2023). Weichselian Glaciation of the Faroe Islands. Bulletin of the Geological Society of Denmark. ISSN 0011-6297. 72, p. 19–100. doi: 10.37570/bgsd-2023-72-02. Full text in Research Archive Show summary

  This paper presents a new complete field mapping of glacial landscapes, landforms and sediments in the Faroe Islands, supplemented by observations from bathymetric maps of the Faroe Shelf. In addition, previous investigations of Quaternary and espe-cially the Weichselian glaciation of the archipelago are reviewed. New cosmogenic nuclide exposure ages indicate that the last extensive glaciation of the Faroe Islands occurred during the Late Weichselian, most likely during the Last Glacial Maximum (LGM; c. 26.5–19.0 cal. ka BP), although a Younger Dryas (c. 12.9–11.7 cal. ka BP) age cannot be entirely excluded. Geomorphological mapping provides a background for reconstructing the extent and type of the glaciation of the Faroe Islands. The reconstructed Weichselian glaciation appears to have had the character of an exten-sive valley glaciation, with several marine glacier termini. The present glaciation of southern Spitsbergen, Svalbard, represents a modern analogue of the reconstructed Weichselian glaciation in the Faroe Islands. The lack of raised coastal features in the Faroe Islands, also at protected sites, suggests that postglacial isostatic uplift was smaller than post-LGM eustatic sea level rise. Numerical glacier reconstructions carried out for different extents of the last extensive Faroese glaciation suggest that such limited postglacial isostatic crustal uplift requires that the Faroe Shelf was not extensively glaciated during the Late Weichselian, but it doubtless was so during at least one of the previous Quaternary glaciations.

• Connolly, Ronan; Soon, Willie; Connolly, Michael; Baliunas, Sallie; Berglund, Johan & Butler, C.J. [Show all 20 contributors for this article] (2023). Challenges in the Detection and Attribution of Northern Hemisphere Surface Temperature Trends Since 1850. Research in Astronomy and Astrophysics (RAA). ISSN 1674-4527. 23(10). doi: 10.1088/1674-4527/acf18e. Full text in Research Archive
• Soon, Willie; Connolly, Ronan; Connolly, Michael; Akasofu, Syun-Ichi; Baliunas, Sallie & Berglund, Johan [Show all 37 contributors for this article] (2023). The Detection and Attribution of Northern Hemisphere Land Surface Warming (1850–2018) in Terms of Human and Natural Factors: Challenges of Inadequate Data. Climate. 11(9). doi: 10.3390/cli11090179. Full text in Research Archive Show summary

  A statistical analysis was applied to Northern Hemisphere land surface temperatures (1850–2018) to try to identify the main drivers of the observed warming since the mid-19th century. Two different temperature estimates were considered—a rural and urban blend (that matches almost exactly with most current estimates) and a rural-only estimate. The rural and urban blend indicates a long-term warming of 0.89 ◦C/century since 1850, while the rural-only indicates 0.55 ◦C/century. This contradicts a common assumption that current thermometer-based global temperature indices are relatively unaffected by urban warming biases. Three main climatic drivers were considered, following the approaches adopted by the Intergovernmental Panel on Climate Change (IPCC)’s recent 6th Assessment Report (AR6): two natural forcings (solar and volcanic) and the composite “all anthropogenic forcings combined” time series recommended by IPCC AR6. The volcanic time series was that recommended by IPCC AR6. Two alternative solar forcing datasets were contrasted. One was the Total Solar Irradiance (TSI) time series that was recommended by IPCC AR6. The other TSI time series was apparently overlooked by IPCC AR6. It was found that altering the temperature estimate and/or the choice of solar forcing dataset resulted in very different conclusions as to the primary drivers of the observed warming. Our analysis focused on the Northern Hemispheric land component of global surface temperatures since this is the most data-rich component. It reveals that important challenges remain for the broader detection and attribution problem of global warming: (1) urbanization bias remains a substantial problem for the global land temperature data; (2) it is still unclear which (if any) of the many TSI time series in the literature are accurate estimates of past TSI; (3) the scientific community is not yet in a position to confidently establish whether the warming since 1850 is mostly human-caused, mostly natural, or some combination. Suggestions for how these scientific challenges might be resolved are offered.

• Bertone, Aldo; Barboux, Chloé; Bodin, Xavier; Bolch, Tobias; Brardinoni, Francesco & Caduff, Rafael [Show all 18 contributors for this article] (2022). Incorporating InSAR kinematics into rock glacier inventories: insights from 11 regions worldwide. The Cryosphere. ISSN 1994-0416. 16(7), p. 2769–2792. doi: 10.5194/tc-16-2769-2022. Full text in Research Archive Show summary

  Rock glaciers are landforms related to permafrost creep that are sensitive to climate variability and change. Their spatial distribution and kinematic behaviour can be critical for managing water resources and geohazards in periglacial areas. Rock glaciers have been inventoried for decades worldwide, often without assessment of their kinematics. The availability of remote sensing data however makes the inclusion of kinematic information potentially feasible, but requires a common methodology in order to create homogeneous inventories. In this context, the International Permafrost Association (IPA) Action Group on rock glacier inventories and kinematics (2018–2023), with the support of the European Space Agency (ESA) Permafrost Climate Change Initiative (CCI) project, is defining standard guidelines for the inclusion of kinematic information within inventories. Here, we demonstrate the feasibility of applying common rules proposed by the Action Group in 11 regions worldwide. Spaceborne interferometric synthetic aperture radar (InSAR) was used to characterise identifiable moving areas related to rock glaciers, applying a manual and a semi-automated approach. Subsequently, these areas were used to assign kinematic information to rock glaciers in existing or newly compiled inventories. More than 5000 moving areas and more than 3600 rock glaciers were classified according to their kinematics. The method and the preliminary results were analysed. We identified drawbacks related to the intrinsic limitations of InSAR and to various applied strategies regarding the integration of non-moving rock glaciers in some investigated regions. This is the first internationally coordinated work that incorporates kinematic attributes within rock glacier inventories at a global scale. The results show the value of designing standardised inventorying procedures for periglacial geomorphology.

• Garcia-Oteyza, J.; Oliva, M.; Palacios, D.; Fernández-Fernández, J.M.; Schimmelpfennig, I. & Andrés, N. [Show all 18 contributors for this article] (2022). Late Glacial deglaciation of the Zackenberg area, NE Greenland. Geomorphology. ISSN 0169-555X. 401. doi: 10.1016/j.geomorph.2022.108125. Full text in Research Archive Show summary

  The Greenland Ice Sheet (GrIS) is a key component of the global climate system. However, our current understanding of the spatio-temporal oscillations and landscape transformation of the GrIS margins since the last glacial cycle is still incomplete. The objective of this work is to study the deglaciation of the Zackenberg Valley (74°N, 20°E), NE Greenland, and the origin of the derived landforms. Based on extensive fieldwork and high-detail geomorphological mapping we identified the different types of landforms, from which those of glacial and paraglacial origin were used to understand the processes driving regional environmental evolution. We applied cosmic-ray exposure (CRE) dating to 32 samples taken from erosive and depositional glacial landforms distributed across the valley. Geomorphological evidence shows that >800-m-thick Late Quaternary glacier filled the valleys and fjords and covered mountain summits. In subsequent phases, as ice thickness decreased, the glacier was limited to the interior of the valley, leaving several lateral moraines. The deglaciation of the Zackenberg Valley that started by ~13.7–12.5 ka also accelerated slope paraglacial processes. Many blocks from lateral moraines were remobilized and fell, reaching the valley floor where they covered the thinning glacier tongue; transforming it into a debris-covered glacier that subsequently melted gradually. By ca. 10.5 ka, the last remnants of glacial ice disappeared from the Zackenberg Valley floor, a chronology of deglaciation that is similar to that observed in other sites across NE Greenland. The results of this work must be considered in similar studies, reinforcing the need to support CRE ages of the different geomorphological phases with paleoclimatic data from other sedimentary records.

• Connolly, Ronan; Soon, Willie; Connolly, Michael; Baliunas, Sallie; Berglund, Johan & Butler, C. John [Show all 23 contributors for this article] (2021). How much has the Sun influenced Northern Hemisphere temperature trends? An ongoing debate. Research in Astronomy and Astrophysics (RAA). ISSN 1674-4527. 21(6). doi: 10.1088/1674-4527/21/6/131. Full text in Research Archive
• Strand, Sarah Marie; Christiansen, Hanne H; Johansson, Margareta; Åkerman, Jonas & Humlum, Ole (2020). Active layer thickening and controls on interannual variability in the Nordic Arctic compared to the circum-Arctic. Permafrost and Periglacial Processes. ISSN 1045-6740. doi: 10.1002/ppp.2088. Full text in Research Archive Show summary

  Active layer probing in northern Sweden, northeast Greenland, and central Svalbard indicates active layer thickening has occurred at Circumpolar Active Layer Monitoring (CALM) sites with long‐term, continuous observations, since the sites were established at these locations in 1978, 1996, and 2000, respectively. The study areas exhibit a reverse latitudinal gradient in average active layer thickness (ALT), which is explained by site geomorphology and climate. Specifically, Svalbard has a more maritime climate and thus the thickest active layer of the study areas (average ALT = 99 cm, 2000–2018). The active layer is thinnest at the northern Sweden sites because it is primarily confined to superficial peat. Interannual variability in ALT is not synchronous across this Nordic Arctic region, but study sites in the same area respond similarly to local meteorology. ALT correlates positively with thawing degree days in Sweden and Greenland, as has been observed in other Arctic regions. However, ALT in Svalbard correlates with freezing degree days, where the maritime Arctic climate results in relatively high and variable winter air temperatures. The difference in annual ALT at adjacent sites is attributed to differences in snow cover and geomorphology. From 2000 to 2018, the average rate of active layer thickening at the Nordic Arctic CALM probing sites was 0.5 cm/yr. The average rate was 1 cm/yr for Nordic Arctic CALM database sites with significant trends, which includes a borehole in addition to probing sites. This range is in line with the circum‐Arctic average of 0.8 cm/yr from 2000 to 2018.

• Chylek, Petr; Hengartner, Nicholas; Lesins, Glen; Klett, James D.; Humlum, Ole & Wyatt, Marcia [Show all 7 contributors for this article] (2014). Isolating the anthropogenic component of Arctic warming. Geophysical Research Letters. ISSN 0094-8276. 41(10), p. 3569–3576. doi: 10.1002/2014GL060184. Full text in Research Archive
• Humlum, Ole (2013). Mindre og mindre global oppvarmning. geoforskning.no. Full text in Research Archive Show summary

  Ny norsk forskning antyder at fremtidens temperaturstigning blir lavere enn tidligere antatt. Det bør få konsekvenser for dagens klimamodeller, mener Ole Humlum.

• Scafetta, Nicola; Humlum, Ole; Solheim, Jan Erik & Stordahl, Kjell (2013). Comment on “The influence of planetary attractions on the solar tachocline” by Callebaut, de Jager and Duhau. Journal of Atmospheric and Solar-Terrestrial Physics. ISSN 1364-6826. 102, p. 368–371. doi: 10.1016/j.jastp.2013.03.007. Full text in Research Archive
• Humlum, Ole; Stordahl, Kjell & Solheim, Jan Erik (2013). The phase relation between atmospheric carbon dioxide and global temperature. Global and Planetary Change. ISSN 0921-8181. 100, p. 51–69. doi: 10.1016/j.gloplacha.2012.08.008. Full text in Research Archive Show summary

  Abstract Using data series on atmospheric carbon dioxide and global temperatures we investigate the phase relation (leads/lags) between these for the period January 1980 to December 2011. Ice cores show atmospheric CO2 variations to lag behind atmospheric temperature changes on a century to millennium scale, but modern temperature is expected to lag changes in atmospheric CO2, as the atmospheric temperature increase since about 1975 generally is assumed to be caused by the modern increase in CO2. In our analysis we use eight well-known datasets; 1) globally averaged well-mixed marine boundary layer CO2 data, 2) HadCRUT3 surface air temperature data, 3) GISS surface air temperature data, 4) NCDC surface air temperature data, 5) HadSST2 sea surface data, 6) UAH lower troposphere temperature data series, 7) CDIAC data on release of anthropogene CO2, and 8) GWP data on volcanic eruptions. Annual cycles are present in all datasets except 7) and 8), and to remove the influence of these we analyze 12-month averaged data. We find a high degree of co-variation between all data series except 7) and 8), but with changes in CO2 always lagging changes in temperature. The maximum positive correlation between CO2 and temperature is found for CO2 lagging 11–12 months in relation to global sea surface temperature, 9.5-10 months to global surface air temperature, and about 9 months to global lower troposphere temperature. The correlation between changes in ocean temperatures and atmospheric CO2 is high, but do not explain all observed changes.

• Lilleøren, Karianne Staalesen; Humlum, Ole; Nesje, Atle & Etzelmuller, Bernd (2013). Holocene development and geomorphic processes at Omnsbreen, southern Norway: Evidence for glacier-permafrost interactions. The Holocene. ISSN 0959-6836. 23(6), p. 796–809. doi: 10.1177/0959683612471984. Full text in Research Archive
• Christiansen, Hanne H; Humlum, Ole & Eckerstorfer, Markus (2013). Central Svalbard 2000-2011 Meteorological Dynamics and Periglacial Landscape Response. Arctic, Antarctic and Alpine research. ISSN 1523-0430. 45(1), p. 6–18. doi: 10.1657/1938-4246-45.1.6. Full text in Research Archive
• Humlum, Ole (2012). Klimadebatt: Humlum svarer Prestrud. geoforskning.no. Full text in Research Archive Show summary

  Professor Ole Humlum lar seg ikke overbevise av Pål Prestruds argument om at «flertallet har rett». Han velger i stedet å støtte seg til empiriske data.

• Solheim, Jan Erik; Stordahl, Kjell & Humlum, Ole (2012). The long sunspot cycle 23 predicts a significant temperature decrease in cycle 24. Journal of Atmospheric and Solar-Terrestrial Physics. ISSN 1364-6826. 80, p. 267–284. doi: 10.1016/j.jastp.2012.02.008. Full text in Research Archive Show summary

  Relations between the length of a sunspot cycle and the average temperature in the same and the next cycle are calculated for a number of meteorological stations in Norway and in the North Atlantic region. No significant trend is found between the length of a cycle and the average temperature in the same cycle, but a significant negative trend is found between the length of a cycle and the temperature in the next cycle. This provides a tool to predict an average temperature decrease of at least 1:0 1C from solar cycle 23 to solar cycle 24 for the stations and areas analyzed. We find for the Norwegian local stations investigated that 25–56% of the temperature increase the last 150 years may be attributed to the Sun. For 3 North Atlantic stations we get 63–72% solar contribution. This points to the Atlantic currents as reinforcing a solar signal.

• Lilleøren, Karianne Staalesen; Etzelmuller, Bernd; Schuler, Thomas; Gisnås, Kjersti & Humlum, Ole (2012). The relative age of mountain permafrost - estimation of Holocene permafrost limits in Norway. Global and Planetary Change. ISSN 0921-8181. 92-93, p. 209–223. doi: 10.1016/j.gloplacha.2012.05.016. Full text in Research Archive
• Farbrot, Herman; Hipp, Tobias; Etzelmuller, Bernd; Isaksen, Ketil; Ødegård, Rune Strand & Schuler, Thomas [Show all 7 contributors for this article] (2011). Air and Ground Temperature Variations Observed along Elevation and Continentality Gradients in Southern Norway. Permafrost and Periglacial Processes. ISSN 1045-6740. 22(4), p. 343–360. doi: 10.1002/ppp.733. Full text in Research Archive
• Humlum, Ole; Solheim, Jan Erik & Stordahl, Kjell (2011). Spectral analysis of the Svalbard temperature record 1912-2010. Advances in Meteorology. ISSN 1687-9309. 2011. doi: 10.1155/2011/175296. Full text in Research Archive Show summary

  Abstract: Future climate development with its prospective anthropogenic effects will occur on a background of natural climatic variations, which may be considerable, and especially in the Arctic. The timing, magnitude and causes of such natural variations however remain poorly understood, and this issue remains important for understanding natural climate variability on decadal- and decennial time scales, and especially to discriminate between natural and anthropogenic influences on current climate change. Using the Svalbard (78oN) surface air temperature record 1912-2010 as an example, we here suggest a road ahead to identify and describe such natural climate variations. By means of Fourier and wavelet analysis the record is decomposed into time-frequency space, to extract information on periodic signals and their amplitude and variation over time. By this we are able to identify several cyclic variations on the time scale investigated. These oscillations are found to be present both in the annual record, as well as in seasonal subsets of the record. Using only three important oscillations it is possible to hindcast the Svalbard temperature record very well. We suggest that such persistent oscillations may potentially be used for forecasting the overall features of future temperature changes for a limited period, about 10-25% of the investigated record length. Our main focus is on identifying the character of recurrent natural temperature variations, but we also comment briefly on possible physical explanations for some of the identified cyclic variations.

• Humlum, Ole; Solheim, Jan Erik & Stordahl, Kjell (2011). Identifying natural contributions to late Holocene climate change. Global and Planetary Change. ISSN 0921-8181. 79(1-2), p. 145–156. doi: 10.1016/j.gloplacha.2011.09.005. Full text in Research Archive Show summary

  Analytic climate models have provided the means to predict potential impacts on future climate by anthropogenic changes in atmospheric composition. However, future climate development will not only be influenced by anthropogenic changes, but also by natural variations. The knowledge on such natural variations and their detailed character, however, still remains incomplete. Here we present a new technique to identify the character of natural climate variations, and from this, to produce testable forecast of future climate. By means of Fourier and wavelet analysis climate series are decomposed into time-frequency space, to extract information on periodic signals embedded in the data series and their amplitude and variation over time. We chose to exemplify the potential of this technique by analysing two climate series, the Svalbard (78oN) surface air temperature series 1912-2010, and the last 4000 yrs of the reconstructed GISP2 surface temperature series from central Greenland. By this we are able to identify several cyclic climate variations which appear persistent on the time scales investigated. Finally, we demonstrate how such persistent natural variations can be used for hindcasting and forecasting climate. Our main focus is on identifying the character (timing, period, amplitude) of such recurrent natural climate variations, but we also comment on the likely physical explanations for some of the identified cyclic climate variations. The causes of millennial climate changes remain poorly understood, and this issue remains important for understanding causes for natural climate variability over decadal- and decennial time scales. We argue that a Fourier and wavelet approach like ours may contribute towards improved understanding of the role of such recurrent natural climate variations in the future climate development.

• Solheim, Jan Erik; Stordahl, Kjell & Humlum, Ole (2011). Solar activity and Svalbard temperatures. Advances in Meteorology. ISSN 1687-9309. 2011. doi: 10.1155/2011/543146. Full text in Research Archive Show summary

  The long temperature series at Svalbard (Longyearbyen) show large variations, and a positive trend since its start in 1912. During this period solar activity has increased, as indicated by shorter solar cycles. The temperature at Svalbard is negatively correlated with the length of the solar cycle. The strongest negative correlation is found with lags of 10-12 years. The relations between the length of a solar cycle and the mean temperature in the following cycle, is used to model Svalbard annual mean temperature, and seasonal temperature variations. Residuals from the annual and winter models show no autocorrelations on the 5 per cent level, which indicates that no additional parameters are needed to explain the temperature variations with 95 per cent significance. These models show that 60 per cent of the annual and winter temperature variations are explained by solar activity. For the spring, summer and fall temperatures autocorrelations in the residuals exists, and additional variables may contribute to the variations. These models can be applied as forecasting models. We predict an annual mean temperature decrease for Svalbard of 3.5±2 oC from solar cycle 23 to solar cycle 24 (2009-20) and a decrease in the winter temperature of ≈6 oC.

• Bye, Erik; Humlum, Ole & Stordahl, Kjell (2011). Sannsynlighet og klimamodeller. Teknisk Ukeblad. ISSN 0040-2354. p. 74–74. Full text in Research Archive
• Christiansen, Hanne Hvidtfeldt; Etzelmuller, Bernd; Isaksen, K; Juliussen, Håvard; Farbrot, Herman & Humlum, Ole [Show all 18 contributors for this article] (2010). The Thermal State of Permafrost in the Nordic Area during the International Polar Year 2007-2009. Permafrost and Periglacial Processes. ISSN 1045-6740. 21(2), p. 156–181. doi: 10.1002/ppp.687. Full text in Research Archive Show summary

  This paper provides a snapshot of the permafrost thermal state in the Nordic area obtained during the International Polar Year (IPY) 2007-2009. Several intensive research campaigns were undertaken within a variety of projects in the Nordic countries to obtain this snapshot. We demonstrate for Scandinavia that both lowland permafrost in palsas and peat plateaus, and large areas of permafrost in the mountains are at temperatures close to 0 degrees C, which makes them sensitive to climatic changes. In Svalbard and northeast Greenland, and also in the highest parts of the mountains in the rest of the Nordic area, the permafrost is somewhat colder, but still only a few degrees below the freezing point. The observations presented from the network of boreholes, more than half of which were established during the IPY, provide an important baseline to assess how future predicted climatic changes may affect the permafrost thermal state in the Nordic area. Time series of active-layer thickness and permafrost temperature conditions in the Nordic area, which are generally only 10 years in length, show generally increasing active-layer depths and risings permafrost temperatures.

View all works in NVA

• Heginbottom, J.A.; Brown, J.; Humlum, Ole & Svensson, Harald (2012). STATE OF THE EARTH’S CRYOSPHERE AT THE BEGINNING OF THE 21ST CENTURY: GLACIERS, GLOBAL SNOW COVER, FLOATING ICE, AND PERMAFROST AND PERIGLACIAL ENVIRONMENTS. U.S. Geological Survey. ISBN 9781411326095. 234 p. Full text in Research Archive

View all works in NVA

• Rouyet, Line; Lilleøren, Karianne Staalesen; Etzelmüller, Bernd; Kääb, Andreas Max; Christiansen, Hanne H. & Humlum, Ole [Show all 9 contributors for this article] (2022). SAR satellite remote sensing for mapping and monitoring Norwegian rock glaciers. Full text in Research Archive
• Rouyet, Line; Christiansen, Hanne H; Humlum, Ole; McDonald, Ashton B. & Lauknes, Tom Rune (2021). Integration of geomorphological mapping and InSAR kinematics for a comprehensive inventory of rock glaciers in Nordenskiöld Land. Full text in Research Archive
• Schrott, Lothar & Humlum, Ole (2017). Introduction to the special issue: permafrost and periglacial research from coasts to mountains. Geomorphology. ISSN 0169-555X. 293, p. 319–320. doi: 10.1016/j.geomorph.2017.08.034. Full text in Research Archive
• Yndestad, Harald; Solheim, Jan-Erik; Humlum, Ole & Falk-Petersen, Stig (2016). The Solar System Large Planets influence on a new Maunder Minimum. Full text in Research Archive
• Solheim, Jan-Erik & Humlum, Ole (2015). Ice Edge: Historic and Future. Full text in Research Archive
• Solheim, Jan-Erik & Humlum, Ole (2015). Historic and future ice limit in the North Atlantic - the Sun and the Moon play a role. Full text in Research Archive
• Humlum, Ole (2015). Climate change since 1850: What may be learnt from observations? Full text in Research Archive
• Gisnås, Kjersti; Etzelmuller, Bernd; Christiansen, Hanne H; Elberling, Bo; Engström, Jonas & Hjort, Jan [Show all 10 contributors for this article] (2014). A First Nordic Permafrost Map for Norway, Sweden and Finland. Full text in Research Archive
• Humlum, Ole (2014). Kommentar 2 til FNs klimapanels sammendrag. geoforskning.no. Full text in Research Archive
• Lilleøren, Karianne Staalesen; Etzelmuller, Bernd; Gisnås, Kjersti; Humlum, Ole & Schuler, Thomas (2013). Relative age and Holocene distribution of permafrost in Norway. Full text in Research Archive
• From, Lars & Humlum, Ole (2013). Forskere: Katastrofer styrer klimadebatten. [Journal]. Jyllandsposten. Full text in Research Archive
• Jødal, Morten; Solheim, Jan-Erik & Humlum, Ole (2013). Mediene slipper ikke til skeptiske klimastemmer. Full text in Research Archive
• Solheim, J.-E. & Humlum, Ole (2013). Naturlige variasjoner. Klassekampen. ISSN 0805-3839. Full text in Research Archive
• Humlum, Ole (2013). Klimatolog i hardt vær. [Journal]. GEO. Full text in Research Archive
• Foss, Håkon Frede; Humlum, Ole & Ellestad, Ole henrik (2013). Klimarealister skaper bekymring. [Journal]. Universitas. Full text in Research Archive
• Humlum, Ole (2013). Takk og kommentar til Prestrud. geoforskning.no. Full text in Research Archive
• Humlum, Ole (2013). Kommentar til FNs klimapanels sammendrag. Full text in Research Archive
• Humlum, Ole & Solheim, Jan-Erik (2013). Naturlige variasjoner og klimamodeller. geoforskning.no. Full text in Research Archive
• Humlum, Ole & Solheim, Jan-Erik (2013). Vulkaner og klimamodeller. geoforskning.no. Full text in Research Archive
• Solheim, Jan-Erik & Humlum, Ole (2013). Kan vi stole på klimamodellene? geoforskning.no. Full text in Research Archive
• Humlum, Ole (2013). Svar og tre spørsmål til Prestrud. geoforskning.no. Full text in Research Archive
• Humlum, Ole (2013). Hvordan blir Svalbards klima de neste 20-25 år? Full text in Research Archive Show summary

  Foredraget tar for seg naturlige klimavariasjoner i forhold til menneskeskapte

• Humlum, Ole (2013). Klimaendringer og årsakssammenheng. Full text in Research Archive
• Humlum, Ole (2013). Relasjonen mellom global temperatur og CO2 – Svar til Prestrud. geoforskning.no. Full text in Research Archive
• Humlum, Ole (2013). Misvisende og urettmessig kritikk. geoforskning.no. Full text in Research Archive
• Humlum, Ole (2013). IPCC’s 5th Assessment med mental dørvakt. geoforskning.no. Full text in Research Archive Show summary

  Antakelsen om at CO2 styrer temperatur har låst FNs klimapanel fast i en feilaktig tankegang og hindrer alternative synspunkter.

• Humlum, Ole (2013). Svalbard climate and meteorology; research history and modern status. Full text in Research Archive
• Humlum, Ole (2013). Examples of natural climate variations missing in climate models; challenges for future climate models. Full text in Research Archive
• Humlum, Ole & Vold, Henrik Brattli (2013). Nå kommer kalde, harde vintre. [Internet]. NRK Viten. Full text in Research Archive Show summary

  Solaktiviteten er på en nedadgående trend, og en britisk forsker mener det er 25 prosent sjanse for at sola blir like svak som under "den lille istid" for 400 år siden. Forskerne er uenige om konsekvensene.

• Humlum, Ole (2013). Mapping natural climate variations: why and how? Full text in Research Archive
• Humlum, Ole (2013). Svalbard; a geological and topographic overview. Full text in Research Archive
• Mörner, N.-A.; Tattersall, R.; Humlum, Ole & Solheim, J.-E. (2013). General conclusions regarding the Planetary–Solar–Terrestrial interaction. Pattern Recognition. ISSN 0031-3203. Full text in Research Archive
• Humlum, Ole (2012). Svalbard Permafrost in a Long Time Perspective. Proceedings from the Tenth International Conference of Permafrost (TICOP), Salekhard, Russia, June 25-29, 2012. 4, p. 118–119. Full text in Research Archive
• Humlum, Ole (2012). UN Climate Panel in big trouble. Dispatch International. p. 5–5. Full text in Research Archive
• Humlum, Ole (2012). Temperatur og atmosfærisk CO2. Full text in Research Archive Show summary

  I en nylig publisert forskningsartikkel hevdet Humlum og medforfatterne at temperaturendringer styrer atmosfæriske endringer av CO2. Artikkelen har blitt heftig debattert, og her svarer Humlum på noe av kritikken og forsøker å oppklare enkelte misforståelser.

• Setså, Ronny & Humlum, Ole (2012). Temperaturen styrer CO2-nivået – ikke omvendt. [Internet]. GEO365 Nettavisen for geomiljøet. Full text in Research Archive Show summary

  Data fra iskjerner har tidligere demonstrert at atmosfæriske endringer i CO2 har etterfulgt temperaturendringer de siste hundretusener av år. Nå har vi funnet bevis for at dette også gjelder i moderne tid, forteller Ole Humlum, professor ved Institutt for geofag ved Universitetet i Oslo og professor II ved Universitetet på Svalbard. Artikkelen, som snart publiseres i tidsskriftet Global and Planetary Change, peker i retning av at det er temperaturendringene på Jorda som har styrt økningen i konsentrasjonen av karbondioksid i atmosfæren de siste tiårene. Forskerne bak artikkelen er, foruten Ole Humlum, Kjell Stordahl, statistiker ved Telenor og Jan-Erik Solheim, professor emeritus ved Institutt for fysikk og teknologi ved Universitetet i Tromsø

• Stordahl, Kjell; Humlum, Ole & Solheim, Jan-Erik (2012). Den globale temperaturen har flatet ut. Forskning.no. ISSN 1891-635X. Full text in Research Archive
• Solheim, Jan-Erik; Humlum, Ole & Stordahl, Kjell (2012). Solar Signals in Temperature Series In and Near the North Atlantic. Full text in Research Archive
• Ellestad, O.H.; Humlum, Ole & Solheim, J.-E. (2012). Klima og folkeopplysning. Full text in Research Archive
• Solheim, Jan-Erik & Humlum, Ole (2012). Jordrotasjonen, Sola, klima og nordlys. Astronomi. ISSN 0802-7587. 42(5), p. 20–25. Full text in Research Archive
• Humlum, Ole (2012). CO2 og klimaskepsis. [Radio]. NRK P2 EKKO. Full text in Research Archive
• Humlum, Ole (2012). Naturlige klimaendringer i evaluering av norsk klimaforskning. geoforskning.no. Full text in Research Archive
• Humlum, Ole (2012). Naturlige klimaendringer er undervurdert i norsk forskning. Forskning.no. ISSN 1891-635X. Full text in Research Archive
• Humlum, Ole (2012). Riggade temperaturtrender. Katternö. 3, p. 5–5. Full text in Research Archive
• Stordahl, Kjell; Humlum, Ole & Solheim, Jan-Erik (2012). Temperaturen styrer atmosfærisk CO2. Forskning.no. ISSN 1891-635X. Full text in Research Archive
• Karlsson, Svenoluf & Humlum, Ole (2012). Arktisk Isminimum. [Journal]. Katternö 2012 Vol. 3, p.42. Full text in Research Archive
• Humlum, Ole (2012). Issues relating to atmospheric CO2 and global temperature that might be reconsidered by IPCC and others. Full text in Research Archive
• Solheim, Jan-Erik; Humlum, Ole & Stordahl, Kjell (2012). Solar Signals in Temperature Series from Locations in and near the North Atlantic. Full text in Research Archive Show summary

  Solar Signals in Temperature Series from Locations In and Near the North Atlantic Jan Erik SOLHEIM 1, Ole HUMLUM 2, Kjell STORDAHL 3 1 University of Tromso, Norway 2 University of Oslo, Norway 3 Telenor, Norway Corresponding author: janesol@online.no +Presenter We have analyzed temperature series from Nordic and Northern Atlantic locations by means of Fourier and wavelet analyses and compared with similar analysis of solar activity proxies. The sunspot period and the Gleissberg period are identified in several of the local time series. In addition we have analyzed the last 4000 years of the reconstructed GISP2 surface temperarture from interior Greenland, which gives a low resolution temperature series until 1855 AD. Here we find dominant periods of the order 1100 and 2800 years, which are also present in the solar proxies covering similar periods. A forecast based on the strongest periods explains the temperature rise experienced after the Little Ice age. A temperature maxium is expected some time this century, before the cooling experienced since the Holocene maximum again will continue. A relation between the length of the sunspot cycle and the mean temperature in sunspot cycles for locations in Norway show that 25 – 60 % of the temperature variations the last 150 years may be attributed to the Sun. For locations as Iceland, Faroe Island and Svalbard the contribution is as high as 72%, For the costal locations investigated a lag of 10-12 years gives the highest correlation between sunspot length and temperature. This is an indication of ocean currents as the main vehicle for transporting heat from lower latitudes to the North Atlantic

• Humlum, Ole (2012). Issues relating to climate modeling, atmospheric CO2 and natural variations. Full text in Research Archive
• Setså, Ronny & Humlum, Ole (2012). Temperaturendring styrer CO2-nivå. [Internet]. Geoforskning.no. Full text in Research Archive
• Humlum, Ole (2012). Klimaalarmisterne har forvekslet årsag og virkning. Dispatch International. Full text in Research Archive
• Humlum, Ole (2012). Past, present and future climate of the European Arctic. Full text in Research Archive
• Humlum, Ole; Stordahl, Kjell & Solheim, Jan-Erik (2012). CO2 globalt og i Oslo. Forskning.no. ISSN 1891-635X. Full text in Research Archive
• Humlum, Ole (2012). Nyanserte meninger om CO2 og klima? Forskning.no. ISSN 1891-635X. Full text in Research Archive
• Ingvaldsen, Randi; Loeng, Harald; Johansen, Sigrid L. & Humlum, Ole (2011). Barents Sea climate variability during the last decade. Full text in Research Archive
• Ellestad, Ole henrik & Humlum, Ole (2011). Hva er god litteratur om temperaturen i Arktis? Forskning.no. ISSN 1891-635X. Full text in Research Archive
• Humlum, Ole & Brich, Randy (2011). NS Exclusive Interview With University of Oslo Physical Geographer Dr. Ole Humlum on Man-Made Climate Change. [Internet]. Nuclear Power Industry News. Full text in Research Archive
• Ellestad, O.H. & Humlum, Ole (2011). Hav og vind gir arktisk klima. Forskning.no. ISSN 1891-635X. Full text in Research Archive
• Humlum, Ole; Bye, Erik & Stordahl, Kjell (2011). Naturlige klimaendringer dominerer. Teknisk Ukeblad. ISSN 0040-2354. Full text in Research Archive
• Ellestad, Ole henrik; Humlum, Ole & Solheim, Jan-Erik (2011). Naturlige variasjoner styrer klima. Forskning.no. ISSN 1891-635X. Full text in Research Archive
• Lilleøren, Karianne Staalesen; Etzelmuller, Bernd; Gisnås, Kjersti & Humlum, Ole (2011). Age and spatial distribution of Holocene permafrost in Norway – model results and implications for glacier-permafrost interaction. Full text in Research Archive
• Humlum, Ole & Ellestad, O. H. (2011). CO2-hypotesens fundamentale problem. Forskning.no. ISSN 1891-635X. Full text in Research Archive
• Lilleøren, Karianne Staalesen; Etzelmuller, Bernd; Gisnås, Kjersti & Humlum, Ole (2011). Interaction between Holocene permafrost and glaciers in Norwegian mountains. Full text in Research Archive
• Humlum, Ole; Solheim, Jan-Erik & Stordahl, Kjell (2011). Klima: naturlige variasjoner eller CO2? Full text in Research Archive
• Humlum, Ole; Stordahl, Kjell & Solheim, J.-E. (2011). Klima - naturlige og menneskeskabte ændringer. Geologisk Nyt. ISSN 0906-6861. p. 4–12. Full text in Research Archive
• Humlum, Ole; Bye, Erik & Stordahl, Kjell (2011). Fortsatt dominans av naturlige klimaendringer. 16, p. 75–75. Full text in Research Archive
• Solheim, Jan Erik & Humlum, Ole (2011). Astronomi og klima - Del I: Planetene og månen dirigerer jordas klima. Fra Fysikkens Verden. ISSN 0015-9247. p. 21–26. Full text in Research Archive
• Humlum, Ole (2011). Permafrost: Modeling considerations for terrestrial environments. Full text in Research Archive
• Humlum, Ole (2011). Menneskeskapt global oppvarmning? Usikkerheter innen klimaforskning. Full text in Research Archive
• Humlum, Ole & Brøyn, May Britt (2011). Innsikt klima. Blir vinteren like kald i år? [Journal]. Aftenposten. Full text in Research Archive
• Etzelmuller, Bernd; Christiansen, Hanne H.; Schuler, Thomas; Farbrot, Herman; Isaksen, Ketil & Ødegård, Rune Strand [Show all 8 contributors for this article] (2010). Modelling of permafrost and seasonal frost in Norway and Iceland – strategies and examples. Full text in Research Archive
• Humlum, Ole (2010). High arctic snow avalanche observations and modelling in Svalbard 2007-2009. Full text in Research Archive
• Humlum, Ole (2010). Past, present and future climate change. Full text in Research Archive
• Humlum, Ole (2010). Klimatisk nåtid og framtid sett i lyset av fortidige temperaturforandringer. Full text in Research Archive
• Humlum, Ole (2010). The Permafrost Research History of Svalbard and Norway. Full text in Research Archive
• Humlum, Ole (2015). Commentary and Analysis on the Whitehead & Associates 2014 NSW Sea-level Report. NIPCC. Full text in Research Archive Show summary

  Carter R.M., de Lange W., Hansen, J.M., Humlum O., Idso C., Kear, D., Legates, D., Mörner, N.A., Ollier C., Singer F. & Soon W. 2014. Commentary and Analysis on the Whitehead & Associates 2014NSWSea-LevelReport. Nongovernmental International Panel on Climate Change (NIPCC), NIPCC Reference: E13.7268, 44 pp.

• Lilleøren, Karianne Staalesen; Etzelmuller, Bernd & Humlum, Ole (2012). Late-Pleistocene and Holocene mountain permafrost geomorphology of Norway and Iceland. Universitetet i Oslo. Full text in Research Archive Show summary

  The combined effect of glacial and periglacial processes on landscape evolution has recently been termed the ‘cryoconditioning’ of landscapes, and largely affect the Fennoscandian landmass. Further, the distribution of permafrost both temporally and spatially during and after the last glaciation affect the overall geomorphic expression. In this thesis the product of landscape evolution is investigated in terms of the geomorphic imprint of glacial and periglacial processes, where the interactions between glaciers and permafrost have been particularly focussed upon. Whereas the glacial variations over the Holocene are relatively well known the same is not the case for the permafrost distribution. As a starting point, inventories of landforms indicating present and former permafrost were compiled for mainland Norway and northern Iceland. The main findings from the inventories were (1) a low abundance of landforms in Norway and a high abundance of landforms in Iceland probably due to differences of bedrock competence, (2) an apparent change in processes leading to rock glacier formation occurred in mid-Holocene from a dry, periglacial regime characterizing early-Holocene to a humid, glacially-dominated regime in mid- to late-Holocene, and (3) warm and maritime permafrost regions are dominated by permafrost landforms formed by the influence of glaciers. For Iceland the occurrence of relict rock glaciers at sea level imply a possible earlier deglaciation or alternatively a less extensive Last Glacial Maximum (LGM) than commonly accepted. As a second step, modelling of permafrost variations over the Holocene was performed in depth and spatially, using a 1D heat flow model and a 2D equilibrium model (CryoGRID1.0). During the warm Holocene Thermal Maximum (HTM) the permafrost survived at high altitudes in southern Norway, whereas during the ‘Little Ice Age’ (LIA) the permafrost reached its greatest extent both in depth and spatially. From these results altitudinal zones of permafrost ages was suggested, analogous to age patterns for Arctic permafrost. From the Neoglaciation until present, the potential of glacier-permafrost interactions has been large. Thirdly, a case study of the currently very small glacier, or glacieret, Omnsbreen which formed and largely disappeared during the LIA was studied in terms of glacial geomorphic evidence for permafrost interaction. Modelled permafrost distribution for the LIA suggest permafrost presence in the Omnsbreen surroundings during its formation and decay, and the landform assemblage present at Omnsbreen is considered representative for mountain glaciers terminating into permafrost. Permafrost is currently only present sporadically in the Omnsbreen surroundings, and the glacier and permafrost underwent a parallel disintegration. The current geomorphic expression of Norway and northern Iceland is significantly affected by long-term interactions between the glacial, subglacial and ground thermal regimes.

View all works in NVA