Behringer, W. (2007) Kulturgeschichte des Klimas: Von der Eiszeit bis zur globalen Erwärmung.- C.H.Beck. (352 S.)

• Ausführliche Besprechungen in scinexx und H-Soz-Kult, 18.03.2008. [date of access: 27.11.2019]

Berndt, C., T. Feseker, T. Treude, S. Krastel, V. Liebetrau, H. Niemann, V. J. Bertics, I. Dumke, K. Dünnbier, B. Ferré, C. Graves, F. Gross, K. Hissmann, V. Hühnerbach, S. Krause, K. Lieser, J. Schauer and L. Steinle (2014) Temporal Constraints on Hydrate-Controlled Methane Seepage off Svalbard.- Science 17 January 2014: Vol. 343 no. 6168 pp. 284-287, DOI: 10.1126/science.1246298.

• Abstract:
  "Methane hydrate is an icelike substance that is stable at high pressure and low temperature in continental margin sediments. Since the discovery of a large number of gas flares at the landward termination of the gas hydrate stability zone off Svalbard, there has been concern that warming bottom waters have started to dissociate large amounts of gas hydrate and that the resulting methane release may possibly accelerate global warming. Here, we corroborate that hydrates play a role in the observed seepage of gas, but we present evidence that seepage off Svalbard has been ongoing for at least 3000 years and that seasonal fluctuations of 1° to 2°C in the bottom-water temperature cause periodic gas hydrate formation and dissociation, which focus seepage at the observed sites."
  [date of access: 17.01.2014]

Berner, U. & H. Streif (2000 - Hrsg.) Klimafakten, Der Rückblick - Ein Schlüssel für die Zukunft.- Schweizerbart'sche Verlagsbuchhandlung, Stuttgart. (238 S.). 4. vollständig überarbeitete Auflage von 2004, mit 259 Seiten.
Sehr zu empfehlen!!

• Hier eine umfangreiche Zusammenstellung von fast 40 Buchbesprechungen durch den Verlag Schweizerbart.

Bintanja, R., G. J. van Oldenborgh, S. S. Drijfhout, B. Wouters, C. A. Katsman (2013) Important role for ocean warming and increased ice-shelf melt in Antarctic sea-ice expansion.- Nature Geoscience (2013) doi:10.1038/ngeo1767 (publ. online 31 March 2013).

• Abstract:
  "Changes in sea ice significantly modulate climate change because of its high reflective and strong insulating nature. In contrast to Arctic sea ice, sea ice surrounding Antarctica has expanded1, with record extent2 in 2010. This ice expansion has previously been attributed to dynamical atmospheric changes that induce atmospheric cooling3. Here we show that accelerated basal melting of Antarctic ice shelves is likely to have contributed significantly to sea-ice expansion. Specifically, we present observations indicating that melt water from Antarctica’s ice shelves accumulates in a cool and fresh surface layer that shields the surface ocean from the warmer deeper waters that are melting the ice shelves. Simulating these processes in a coupled climate model we find that cool and fresh surface water from ice-shelf melt indeed leads to expanding sea ice in austral autumn and winter. This powerful negative feedback counteracts Southern Hemispheric atmospheric warming. Although changes in atmospheric dynamics most likely govern regional sea-ice trends4, our analyses indicate that the overall sea-ice trend is dominated by increased ice-shelf melt. We suggest that cool sea surface temperatures around Antarctica could offset projected snowfall increases in Antarctica, with implications for estimates of future sea-level rise."
  [date of access: 03.04.2013]

BMBF (2003) "Herausforderung Klimawandel" - 3.9MB, 60 Seiten - Bundesministerium für Bildung und Forschung (BMBF). Bonn / Berlin 2003 [date of access: 07.03.05]

• S.10: "Daher ist das [Kyoto-]Protokoll in seiner jetzigen Form kaum geeignet, das Klima zu stabilisieren. Seine Wirkung ist eher im politischen Bereich zu finden, da es die einzige völkerrechtliche Basis für weitergehende Massnahmen darstellt."
• S.51: "... die Auswirkungen des Kyoto-Protokolls sind nur vereinzelt hochgerechnet worden. Danach scheint die im Kyoto-Protokoll vorgesehene Reduktion der Treibhausgas-Emissionen der Industrieländer nur einen geringen Effekt auf die Temperaturentwicklung zu haben ...".

Böttcher, C.J.F. (1999) The use and misuse of science in policy making.- In: Climate policy after Kyoto, pp 40-9 (T.R. Gerholm, edit.) - Mit Beiträgen von Eric Moberg, Wibjörn Karlén, Jarl Ahlbeck, Tor Ragnar Gerholm, Jarl Ahlbeck, Richard S. Lindzen, Gösta Wallin, Marian Radetzki, Karl-Axel Edin, Bert Bolin.

• Summary:
  " The Kyoto Convention recommends reductions in emissions of CO₂ and other greenhouse gases, to mitigate the rate of climate change. Lively debate has taken place in many countries, not least over the political and economic implications.
  The basis for the Kyoto discussions was a set of studies commissioned, compiled and published by the UN's International Panel on Climate Change (IPCC). At first glance this scientific foundation plainly shows that significant climate change will occur unless emissions of greenhouse gases are sharply curtailed. On closer examination, the scientific evidence provided in the IPCC material is far from clear. Reputable scientists have expressed critical views about the interpretation of the scientific results and, even more, of the way the material is being used for policy purposes. The main purpose of this book is to voice this critique.
  To give the reader some context, a central section from the IPCC's basic document is presented first. There follow nine papers, by prominent natural and social scientists, in which the reasons for their sceptical attitudes are developed. A final paper by Professor Bert Bolin, chairman of the IPCC during the time when most of the material was produced, provides a response and commentary to the critique.
  The aim of the editor and authors, in presenting the material in this way, rather than as a polemical tract, is to leave open to the reader the question: Is global warming a consequence of man's activities, or are there other reasons; if so, is adopting policies with significant economic consequences, a reasonable response?"
  [date of access: 09.05.2007]

• Abstract:
  " Many palaeoclimate records from the North Atlantic region show a pattern of rapid climate oscillations, the so-called Dansgaard–Oeschger events, with a quasi-periodicity of approx. 1,470 years for the late glacial period (...). Various hypotheses have been suggested to explain these rapid temperature shifts, including internal oscillations in the climate system and external forcing, possibly from the Sun (...). But whereas pronounced solar cycles of approx. 87 and approx. 210 years are well known (...), a approx. 1,470-year solar cycle has not been detected (...). Here we show that an intermediate-complexity climate model with glacial climate conditions simulates rapid climate shifts similar to the Dansgaard–Oeschger events with a spacing of 1,470 years when forced by periodic freshwater input into the North Atlantic Ocean in cycles of approx. 87 and approx. 210 years. We attribute the robust 1,470-year response time to the superposition of the two shorter cycles, together with strongly nonlinear dynamics and the long characteristic timescale of the thermohaline circulation. For Holocene conditions, similar events do not occur. We conclude that the glacial 1,470-year climate cycles could have been triggered by solar forcing despite the absence of a 1,470-year solar cycle."
  
  
• "Die Bedeutung dieser Untersuchung liegt darin, daß sie uns zeigt, wie komplex die Reaktionen des Systems Erde sind", so Prof. Kurt Roth, Direktor des Instituts für Umweltphysik der Universität Heidelberg. "Während bestimmter Zeiten, hier der Eiszeit, reagiert es extrem empfindlich auf Einflüsse von außen. Die Zeitskala der Reaktion entspricht dabei nicht immer der Zeitskala des Auslösers. Dies ist eine wesentliche Erkenntnis, die auch Eingang in das aktuelle Verständnis unseres Klimasystems finden wird."
  
  (Zit. aus: "Schwankende Sonnenaktivität löste Klimawechsel aus" - 3Sat - Nano) [date of access: 09.05.2007]

• Abstract:
  "In 1942 Robert K. Merton tried to demonstrate the structure of the normative system of science by specifying the norms that characterized it. The norms were assigned the abbreviation CUDOs: Communism, Universalism, Dis-interestedness, and Organized skepticism. Using the results of an on-line survey of climate scientists concerning the norms of science, this paper explores the climate scientists’ subscription to these norms. The data suggests that while Merton’s CUDOs remain the overall guiding moral principles, they are not fully endorsed or present in the conduct of climate scientists: there is a tendency to withhold results until publication, there is the intention of maintaining property rights, there is external influence defining research and the tendency to assign the significance of authored work according to the status of the author rather than content of the paper.These are contrary to the norms of science as proposed by Robert K. Merton."

Briffa, K.R., Osborn, T.J. and Schweingruber, F.H. (2004) Large-scale Temperature inferences from tree rings: a review.- Global & Planetary Change 40: 11-26. - 16 S.

• Abstract:
  "This paper is concerned with dendroclimatic research aimed at representing the history of very large-scale temperature changes. It describes recent analyses of the data from a widespread network of tree-ring chronologies, made up of ring width and densitometric measurement data spanning three to six centuries. The network was built over many years from trees selected to maximise their sensitivity to changing temperature. This strategy was adopted so that temperature reconstructions might be achieved at both regional and very large spatial scales. The focus here is on the use of one growth parameter: maximum latewood density (MXD). The detailed nature of the temperature sensitivity of MXD across the whole network has been explored and the dominant common influence of mean April–September temperature on MXD variability is demonstrated. Different approaches to reconstructing past temperature for this season include the production of detailed year-by-year gridded maps and wider regional integrations in the form of subcontinental and quasi-hemispheric-scale histories of temperature variability spanning some six centuries. These ‘hemispheric’ summer series can be compared with other reconstructions of temperature changes for the Northern Hemisphere over the last millennium. The tree-ring-based temperature reconstructions show the clear cooling effect of large explosive volcanic eruptions. They also exhibit greater century-timescale variability than is apparent in the other hemispheric series and suggest that the late 15th and the 16th centuries were cooler than indicated by some other data. However, in many tree-ring chronologies, we do not observe the expected rate of ring density increases that would be compatible with observed late 20th century warming. This changing climate sensitivity may be the result of other environmental factors that have, since the 1950s, increasingly acted to reduce tree-ring density below the level expected on the basis of summer temperature changes. This prevents us from claiming unprecedented hemispheric warming during recent decades on the basis of these tree-ring density data alone. Here we show very preliminary results of an investigation of the links between recent changes in MXD and ozone (the latter assumed to be associated with the incidence of UV radiation at the ground). D 2003 Elsevier B.V. All rights reserved."

• Abstract:
  "Our knowledge of long-term human effects on greenhouse gas levels in the atmosphere comes from air trapped in ice cores taken from polar ice sheets. These ice core samples allow researchers to place modern changes in the context of natural variations over hundreds of thousands of years. In his Perspective, Brook discusses results reported in the same issue by Siegenthaler et al. and by Spahni et al. based on new samples obtained by the European Project for Ice Coring in Antarctica (EPICA). The new long records of carbon dioxide, methane, and nitrous oxide from EPICA extend the window on greenhouse gas levels to 650,000 years. The results confirm that the modern atmosphere is highly anomalous and reinforce the view that greenhouse gases and climate are intimately related."
  Source: ScienceMag [date of access: 30.04.07]
  
  Anmerkung: In den Abbildungen zeigen die mehr oder weniger parallelen Verläufe der Methan- und Kohlendioxidgehalte sowie der Temperaturdynamik deutlich, dass der Anstieg der Kohlendioxidgehalte auffallend NACH der Temperaturzunahme erfolgt.

Bryden, Harry L., et al. (2005)Slowing of the Atlantic Meridional Overturning Circulation at 25° N.- Nature 438: 655-57 [doi: 10.1038/nature04385].

• Abstract:
  "The Atlantic meridional overturning circulation carries warm upper waters into far-northern latitudes and returns cold deep waters southward across the Equator1. Its heat transport makes a substantial contribution to the moderate climate of maritime and continental Europe, and any slowdown in the overturning circulation would have profound implications for climate change. A transatlantic section along latitude 25° N has been used as a baseline for estimating the overturning circulation and associated heat transport2, 3, 4. Here we analyse a new 25° N transatlantic section and compare it with four previous sections taken over the past five decades.

  The comparison suggests that the Atlantic meridional overturning circulation has slowed by about 30 per cent between 1957 and 2004. Whereas the northward transport in the Gulf Stream across 25° N has remained nearly constant, the slowing is evident both in a 50 per cent larger southward-moving mid-ocean recirculation of thermocline waters, and also in a 50 per cent decrease in the southward transport of lower North Atlantic Deep Water between 3,000 and 5,000 m in depth. In 2004, more of the northward Gulf Stream flow was recirculating back southward in the thermocline within the subtropical gyre, and less was returning southward at depth."

Vgl. dazu auch:

Govindan et al. (2002) Global climate models violate scaling of the observed atmospheric variability.
Eichner et al. (2003) Power-law persistence and trends in the atmosphere: A detailed study of long temperature records.

Caesar, L., G.D. McCarthy, D.J.R. Thornalley, N. Cahill & S. Rahmstorf (2021) Current Atlantic Meridional Overturning Circulation weakest in last millennium. Nat. Geosci. https://doi.org/10.1038/s41561-021-00699-z

Abstract:
"The Atlantic Meridional Overturning Circulation (AMOC)—one of Earth’s major ocean circulation systems—redistributes heat on our planet and has a major impact on climate. Here, we compare a variety of published proxy records to reconstruct the evolution of the AMOC since about ad 400. A fairly consistent picture of the AMOC emerges: after a long and relatively stable period, there was an initial weakening starting in the nineteenth century, followed by a second, more rapid, decline in the mid-twentieth century, leading to the weakest state of the AMOC occurring in recent decades." [date of access: 01.03.2021]

Camp, Charles D. and Ka Kit Tung (2007) Surface warming by the solar cycle as revealed by the composite mean difference projection.- Geophysical Research Letters (GRL) paper 10.1029/2007GL030207, 2007 (Department of Applied Mathematics, University of Washington, Seattle, Washington, U.S.A.)

"The existence of a long-term trend in solar output is controversial, but its periodic change within an 11-year cycle has been measured by satellites.
To assess how this less-controversial oscillatory forcing affects climate on Earth, Camp and Tung compare surface temperature measurements across the globe between years of solar maximum (with higher heat output) and years of solar minimum.
They find that times of high solar activity are on average 0.2º C warmer than times of low solar activity, and that there is a polar amplification of the warming. This result is the first to document a statistically significant globally coherent temperature response to the solar cycle, the authors note." ScienceDaily (Aug. 2, 2007)

Charlson, Robert J., Francisco PJ Valero, John H. Seinfeld (2005) "ATMOSPHERIC SCIENCE: In Search of Balance".- Science Magazine, 1. April 2005, Vol. 308, p.806-807.

Abstract:
"Emissions of gases such as carbon dioxide are responsible for an enhanced greenhouse effect, but human-made changes in Earth's reflectivity via changes in clouds and aerosols may partly counteract the resulting warming. In their Perspective, Charlson et al. discuss attempts to estimate the changes in reflectivity (or albedo) both via observations and through model studies. Papers in this issue by Wielicki et al., Pinker et al., and Wild et al. report such observational estimates. However, Charlson et al. conclude that the uncertainties are still large and that sustained, direct, and simultaneous observations of albedo with all methods at researchers' disposal are necessary to resolve this important question of how much albedo is changing as a result of human activities."

Christy, J. R. (2016) U.S. House Committee on Science, Space & Technology, 2 Feb 2016, Testimony of John R. Christy, University of Alabama in Huntsville. [23 S.]

• on (1.1) Upper air temperature data from satellites and balloons (p.1),
• on (1.2) Surface temperature issues (p.6),
• on (1.2.b) The new NOAA surface temperature dataset (p.7),
• on (2) How well do we understandclimatechange? (10),
• on (3) Climate Impact of Regulations(i.e. Paris)Will Not Be Attributable or Detectable (p.12),
• Summary (p.15).
• Appendix A: Alleged impacts of human-induced climate changes regarding extreme events, The Disappointing Scientific Process,
  • Summary of Extract:
    "The messages of the two points outlined in the extract above are: (1) the claims about increases in frequency and intensity of extreme events are generally not supported by actual observations and, (2) official information about climate science is largely controlled by agencies through (a) funding choices for research and (b) by the carefully-selected (i.e. biased) authorship of reports such as the EPA Endangerment Finding and the National Climate Assessment."

John Christy is Professor of Atmospheric Science and Director of the Earth System Science Center at the University of Alabama in Huntsville or UAH. He is also Alabama's State Climatologist and has recently served as a Lead Author of the U.N.'s Intergovernmental Panel on Climate Change (IPCC). He belongs to the "so-called climate skeptics".

Reaktion von "RealClimate" vom 7. Mai 2016, dem Sprachrohr der AGW-Apologeten, finden Sie HIER.

Christy, J. R., W. B. Norris, R. W. Spencer, and J. J. Hnilo (2007), Tropospheric temperature change since 1979 from tropical radiosonde and satellite measurements, J. Geophys. Res., 112, D06102, doi:10.1029/2005JD006881.

Abstract:
"Temperature change of the lower troposphere (LT) in the tropics (20°S–20°N) during the period 1979–2004 is examined using 58 radiosonde (sonde) stations and the microwave-based satellite data sets of the University of Alabama in Huntsville (UAH v5.2) and Remote Sensing Systems (RSS v2.1). At the 29 stations that make both day and night observations, the average nighttime trend (+0.12 K decade-1) is 0.05 K decade-1 more positive than that for the daytime (+0.07 K decade-1) in the unadjusted observations, an unlikely physical possibility indicating adjustments are needed. At the 58 sites the UAH data indicate a trend of +0.08 K decade-1, the RSS data, +0.15. When the largest discontinuities in the sondes are detected and removed through comparison with UAH data, the trend of day and night releases combined becomes +0.09, and using RSS data, +0.12. Relative to several data sets, the RSS data show a warming shift, broadly occurring in 1992, of between +0.07 K and +0.13 K. Because the shift occurs at the time NOAA-12 readings began to be merged into the satellite data stream and large NOAA-11 adjustments were applied, the discrepancy appears to be due to bias adjustment procedures. Several comparisons are consistent with a 26-year trend and error estimate for the UAH LT product for the full tropics of +0.05 ± 0.07, which is very likely less than the tropical surface trend of +0.13 K decade-1."

 Abb. A2-28/01:
"Temperaturabweichungen" (Variations from average) ab Januar 1979. Temperaturen der unteren Troposphäre mit Hilfe von Satellitenmessungen sind aktuell der "zuverlässigste Weg zur Analyse globaler Temperaturveränderungen, da sie die gesamte Atmosphäre gleichmäßig erfassen und Messfehler durch Temperatureinflüsse urbaner Ballungszentren vermeiden.

"Folgende Veränderungen haben sich seit 1979 ergeben:

• globaler Trend pro Dekade: + 0,085 °C
• nördliche Hemisphäre: + 0,155 °C
• südliche Hemisphäre: + 0,014 °C"

Christy, J.R. Roy W. Spencer, William B. Norris, William D. Braswell, and David E. Parker (2003) Error estimates of Version 5.0 of MSU-AMSU bulk atmospheric temperatures.- Journal of Atmospheric and Oceanic Technology 20: 613-629.

• Abstract:
  "Deep-layer temperatures derived from satellite-borne microwave sensors since 1979 are revised (version 5.0) to account for 1) a change from microwave sounding units (MSUs) to the advanced MSUs (AMSUs) and 2) an improved diurnal drift adjustment for tropospheric products. AMSU data, beginning in 1998, show characteristics indistinguishable from the earlier MSU products. MSU–AMSU error estimates are calculated through comparisons with radiosonde-simulated bulk temperatures for the low–middle troposphere (TLT), midtroposphere (TMT), and lower stratosphere (TLS.) Monthly (annual) standard errors for global mean anomalies of TLT satellite temperatures are estimated at 0.10°C (0.07°C). The TLT (TMT) trend for January 1979 to April 2002 is estimated as +0.06° (+0.02°) ±0.05°C decade–1 (95% confidence interval). Error estimates for TLS temperatures are less well characterized due to significant heterogeneities in the radiosonde data at high altitudes, though evidence is presented to suggest that since 1979 the trend is -0.51° ± 0.10°C decade–1."

• Abstract:
  We provide an analysis of Greenland temperature records to compare the current (1995–2005) warming period with the previous (1920–1930) Greenland warming. We find that the current Greenland warming is not unprecedented in recent Greenland history. Temperature increases in the two warming periods are of a similar magnitude, however, the rate of warming in 1920–1930 was about 50% higher than that in 1995–2005.

• Abstract:
  "The Greenland coastal temperatures have followed the early 20th century global warming trend. Since 1940, however, the Greenland coastal stations data have undergone predominantly a cooling trend. At the summit of the Greenland ice sheet the summer average temperature has decreased at the rate of 2.2 °C per decade since the beginning of the measurements in 1987. This suggests that the Greenland ice sheet and coastal regions are not following the current global warming trend. A considerable and rapid warming over all of coastal Greenland occurred in the 1920s when the average annual surface air temperature rose between 2 and 4 °C in less than ten years (at some stations the increase in winter temperature was as high as 6 °C). This rapid warming, at a time when the change in anthropogenic production of greenhouse gases was well below the current level, suggests a high natural variability in the regional climate. High anticorrelations (r = -0.84 to -0.93) between the NAO (North Atlantic Oscillation) index and Greenland temperature time series suggest a physical connection between these processes. Therefore, the future changes in the NAO and Northern Annular Mode may be of critical consequence to the future temperature forcing of the Greenland ice sheet melt rates."

• "Abstract:
  The buildup of CO2 is a reality, monitored with increasing precision since 1957 and inferred for much earlier dates. A statistical section gives the monitored values to 1980, as well as a review of a long series of measurements made at Mauna Loa by the pioneers of such monitoring, Charles D. Keeling, Robert B. Bacastow, and Timothy P. Whorf. The book discusses internal transport processes in the ocean, of ocean-atmosphere interaction, of the magnitude of forest and soil carbon wastage, of the future course of fossil-fuel consumption. Yet something else emerges, too: if the CO/sub 2/ buildup continues; if the big general circulation models are right about its impact on climate, and if we have not miscalculated the potential role of the oceans, then we face a climatic change in the next century and a half like nothing the post-glacial world, and hence civilized humanity, has seen."

Cubasch, U. (2002) Variabilität der Sonne und Klimaschwankungen.- promet, Jahrg. 28, Nr. 3/4, S.123-132. - File [nicht mehr online]

• "Zusammenfassung:
  Um den Effekt der Sonnenvariabilität auf das Klima zu berechnen, treiben zwei Schätzungen der Sonnenintensitätsvariationen während der letzten drei Jahrhunderte numerische Simulationen an. Die Modelle, die dafür eingesetzt werden, sind dieselben gekoppelten Ozean-Atmosphären-Klimamodelle, die angewendet werden, um den anthropogenen Einfluss auf das Klima zu berechnen. Alle Simulationen zeigen, dass die bodennahe Lufttemperatur und die vertikale Temperaturverteilung in der Atmosphäre auf die Variabilität der Sonneneinstrahlung reagieren. Es gibt sogar Anzeichen, dass die thermohaline Zirkulation im Nordatlantik durch grosse Amplitudenschwankungen in der Sonneneinstrahlung beeinflusst wird. In der Stratosphäre dagegen, ergeben sich deutliche Unterschiede zwischen den Antwortmustern, wie sie beobachtet werden und wie sie derzeit simuliert werden. Diese Unterschiede sind besonders deutlich beim 11-Jahres Zyklus. Eine ungenügende Repräsentation der Stratosphäre oder eine fehlende Parametrisierung, die ein Anwachsen der stratosphärischen Ozonkonzentration durch die vermehrte UV-Einstrahlung bei einem Anwachsen der Sonnenintensität beim Maximum des solaren Zyklus beschreibt, könnte dafür die Ursache sein."

Cubasch, U. & D. Kasang (2000) Anthropogener Klimawandel.- Klett-Perthes- Verlag, Stuttgart, ISBN 3-623-00856-7, 128 S.

• Abstract:
  "To estimate the effect of the solar variability on the climate, two estimates of the solar intensity variations during the last three centuries have been used as forcing in numerical simulations. The model employed to carry out the experiments was the same coupled global ocean-atmosphere model used in a number of studies to assess the effect of the anthropogenic greenhouse gases on climate. The near surface temperature and the tropospheric temperature distribution shows a clear response to the variability of the solar input. Even the thermohaline circulation reacts on the large amplitudes in the forcing. In the stratosphere, the response pattern is similar as in the observations, however, the 11-year cycle found in the forcing data does not excite an appreciable response. This might be due to the missing parameterisation of the increase in the UV-radiation at the solar cycle maximum and the connected increase of the stratospheric ozone concentration."

Cubasch, U., E. Zorita, J.F. Gonzalez-Rouco, H.v. Storch and I. Fast (2004) Simulating the last 1000 years with a 3d coupled model. - File, 17 S.

• Abstract - page 1:
  "A simulation of the climate of the last millennium with a state-of-the art ocean-atmosphere climate model, which has been forced with solar variability, volcanism and the change in anthropogenic greenhouse gases, shows global temperatures during the Little Ice Age of the order of 1 K colder than present. This is markedly colder than some accepted empirical reconstructions from proxy data. In this simulation temperature minima are reached in the Late Maunder Minimum, (around 1700 A.D.) and the Dalton Minimum (1820 A.D.), with global temperature about 1.2 K colder than today. The model also produces a Medieval Warm Period around 1100 A.D., with global temperatures approximately equal to present values. A combination of model and tree-ring data leads to an improved temperature estimate for Northern Europe, but not for Southern Europe."
  
  
• Abstract - page 8:
  " The discrepancies between model simulation and empirical reconstructions are discussed in terms of the climate sensitivity to changes in the solar constant. We find that whereas the model response to changes is roughly constant along the simulation and agrees with the sensitivity derived from instrumental data, the empirical reconstructions show a lower sensitivity in the 20th century, and a much lower one in the past centuries, thus pointing to potential inconsistencies between the reconstructed temperature and solar constant. It has been tried to use the model data to fill gaps in the proxy-data records. This produces an improved temperature curve for northern Europe. Problems, however arise in southern Europe."

Cubasch, U., B. D. Santer & G. C. Hegerl (1995) Klimamodelle - wo stehen wir? - Phys. Bl. 4, 269-276.

• Statement:
  "Am 20. Februar 1995 meldeten es alle Nachrichtenagenturen: Mit 95prozentiger Wahrscheinlichkeit ist die in den Klimabeobachtungen verzeichnete globale Erwärmung um 0,7 °C seit Beginn der Industrialisierung anthropogenen Ursprungs. Dieses Ergebnis einer komplexen Analyse von Klimamodellrechnungen am Deutschen Klimarechenzentrum in Hamburg gab dessen Direktor Klaus Hasselmann an diesem Tag der Bundesregierung bekannt. Der folgende Beitrag von Mitarbeitern dieses Zentrums ist eine kritische Analyse der Methodik von Klimasimultationsrechnungen. Er beschreibt, wie man mit Hilfe von gekoppelten Ozean-Atmosphäre-Modellen zu einer solchen Aussage gelangt, welche Probleme dabei auftreten und wo die Grenzen der heutigen Modelle liegen. (Red.)"

Cunningham et al. (2007)Temporal Variability of the Atlantic Meridional Overturning Circulation at 26.5°N.- Science 17 August 2007: Vol. 317. no. 5840, pp. 935 - 938, DOI: 10.1126/science.1141304

• Abstract:
  "The vigor of Atlantic meridional overturning circulation (MOC) is thought to be vulnerable to global warming, but its short-term temporal variability is unknown so changes inferred from sparse observations on the decadal time scale of recent climate change are uncertain. We combine continuous measurements of the MOC (beginning in 2004) using the purposefully designed transatlantic Rapid Climate Change array of moored instruments deployed along 26.5°N, with time series of Gulf Stream transport and surface-layer Ekman transport to quantify its intra-annual variability. The year-long average overturning is 18.7 ± 5.6 sverdrups (Sv) (range: 4.0 to 34.9 Sv, where 1 Sv = a flow of ocean water of 106 cubic meters per second). Interannual changes in the overturning can be monitored with a resolution of 1.5 Sv."

Dahl-Jensen, D. et al. (2013) Eemian interglacial reconstructed from a Greenland folded ice core.- Nature 493, 489–494 (24 January 2013) doi:10.1038/nature11789 (Published online 23 January 2013)

• Abstract:
  "Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling (‘NEEM’) ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 ± 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 ± 250 metres, reaching surface elevations 122,000 years ago of 130 ± 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future".

Dansgaard, W., S. J. Johnsen, H. B. Clausen, D. Dahl-Jensen, N. S. Gundestrup, C. U. Hammer, C. S. Hvidberg, J. P. Steffensen, A. E. Sveinbjörnsdottir, J. Jouzel & G. Bond (1993) Evidence for general instability of past climate from a 250-kyr ice-core record.- Nature 364, 218 - 220 (15 July 1993); doi:10.1038/364218a0

• Abstract:
  "RECENT results (...) from two ice cores drilled in central Greenland have revealed large, abrupt climate changes of at least regional extent during the late stages of the last glaciation, suggesting that climate in the North Atlantic region is able to reorganize itself rapidly, perhaps even within a few decades. Here we present a detailed stable-isotope record for the full length of the Greenland Ice-core Project Summit ice core, extending over the past 250 kyr according to a calculated timescale. We find that climate instability was not confined to the last glaciation, but appears also to have been marked during the last interglacial (as explored more fully in a companion paper (..)) and during the previous Saale–Holstein glacial cycle. This is in contrast with the extreme stability of the Holocene, suggesting that recent climate stability may be the exception rather than the rule. The last interglacial seems to have lasted longer than is implied by the deep-sea SPECMAP record (...), in agreement with other land-based observations (...). We suggest that climate instability in the early part of the last interglacial may have delayed the melting of the Saalean ice sheets in America and Eurasia, perhaps accounting for this discrepancy."

Dansgaard, W., and S. J. Johnsen (1969) A flow model and a time scale for the ice core from Camp Century, Greenland.- J. Glaciol. 8(53):215-223.

• Abstract:
  "A flow model is described for the Camp Century area in Greenland. The horizontal velocity profile along the core is assumed to be uniform from the surface down to y = 400 m above the bottom. Below this level, the horizontal velocity v x , is assumed to decrease proportionally to y. Furthermore, at a given y, v x is assumed to be proportional to the distance x from the ice divide. The resulting vertical strain-rate under steady-state conditions gives the age of the ice as a function of y. The flow model has explained the measured temperature profile, and the time scale has been verified by comparison between observed stable isotope variations and past climatic changes (at least 70 000 years back in time) estimated by other methods."
  
  
• Zusammenfassung:
  "Für das Gebiet von Camp Century in Grönland wird ein Fliessmodell beschrieben. Das Horizontalgeschwindigkeitsprofil entlang des Kerns wird von der Oberfläche bis zu y = 400 m über dem Boden als gleichförmig angenommen. Darunter wird eine Abnahme der Horizontalgeschwindigkeit v x proportional zu y vorausgesetzt. Weiterhin wird unterstellt. dass sich für ein gegebenes y v x proportional zur Entfernung x von der Eisscheide verhält. Die resultierende vertikale Verformungsgeschwindigkeit unter stetigen Bedingungen ergibt das Alter des Eiscs als eine Funktion von y. Das Fliessmodell erklärt das gemessene Temperaturprofil: die Zeitskala wird durch einen Vergleich zwischen beobachteten Variationen stabiler Isotope und früheren Klimaschwankungen (zumindest in den letzten 70 000 Jahren), die mit anderen Methoden abgeschätzt werden, bestätigt."
  

Dansgaard, W., S. J. Johnsen, J. Møller, C. C. Langway Jr. (1969) One Thousand Centuries of Climatic Record from Camp Century on the Greenland Ice Sheet.- Science 17 Oct 1969: Vol. 166, Issue 3903, pp. 377-380, DOI: 10.1126/science.166.3903.377.

• "Abstract:
  A correlation of time with depth has been evaluated for the Camp Century, Greenland, 1390 meter deep ice core. Oxygen isotopes in approximately 1600 samples throughout the core have been analyzed. Long-term variations in the isotopic composition of the ice reflect the climatic changes during the past nearly 100,000 years. Climatic oscillations with periods of 120, 940, and 13,000 years are observed."

• Science-Remarks:
  "Sea-level rises and falls as Earth's giant ice sheets shrink and grow. It has been thought that sea level around 81,000 years ago - well into the last glacial period - was 15 to 20 meters below that of today and, thus, that the ice sheets were more extensive. Dorale et al. (p. 860; see the Perspective by Edwards) now challenge this view. A speleothem that has been intermittently submerged in a cave on the island of Mallorca was dated to show that, historically, sea level was more than a meter above its present height. This data implies that temperatures were as high as or higher than now, even though the concentration of CO₂ in the atmosphere was much lower."
• Abstract:
  "Global sea level and Earth’s climate are closely linked. Using speleothem encrustations from coastal caves on the island of Mallorca, we determined that western Mediterranean relative sea level was ~1 meter above modern sea level ~81,000 years ago during marine isotope stage (MIS) 5a. Although our findings seemingly conflict with the eustatic sea-level curve of far-field sites, they corroborate an alternative view that MIS 5a was at least as ice-free as the present, and they challenge the prevailing view of MIS 5 sea-level history and certain facets of ice-age theory."

• "Abstract:
  Long ice cores from Greenland yield records of annually resolved climate change for the past ten to twenty thousand years, and decadal resolution for one hundred thousand years or more. These cores are ideally suited to determine the rapidity with which major climate changes occur. The termination of the Younger Dryas, which marks the end of the last glacial period, appears to have occurred in less than a human lifetime in terms of oxygen isotopic evidence (a proxy for temperature), in less than a generation (20 years) for dust content and deuterium excess (proxies for winds and sea-surface conditions), and in only a few years for the accumulation rate of snow. Similarly rapid changes have been observed for stadial-interstadial climate shifts (Dansgaard-Oeschger cycles) which punctuate the climate of the last glacial period. These changes appear to be too rapid to be attributed to external orbital forcings, and may result from internal instabilities in the Earth's atmosphere-ocean system or periodic massive iceberg discharges associated with ice sheet instability (Heinrich events). In contrast, the Holocene climate of the Arctic appears to have been relatively stable. However, the potential for unstable interglacials, with very rapid, shortlived climatic deteriorations, has been raised by results from the lower part of the GRIP ice core. These results have not been confirmed by other ice cores, notably the nearby GISP2 core.
  
  Evidence from other records of climate during the Eemian interglacial have yielded mixed results, and the potential for rapid climate change during interglacial periods remains one of the most intriguing gaps in our understanding of the nature of major Quaternary climate change."
  

• Excerpt 'IV. DISCUSSION':
  "... When analyzing warming phenomena in the atmosphere, it is essential to employ methods that can distinguish, in a systematic way, between trends and long-term correlations—in contradistinction to a number of conventional schemes that have been applied in the past. These schemes run the risk of mixing up the correlatedness of natural climate system variability with entire regime shifts enforced by anthropogenic interference through greenhouse gas emissions. The fact that we found it difficult to discern warming trends at many stations that are not located in rapidly developing urban areas may indicate that the actual increase in global temperature caused by anthropogenic perturbation is less pronounced than estimated in the last IPCC (...) report."

Vgl. dazu auch:

Govindan et al. (2002) Global climate models violate scaling of the observed atmospheric variability.
Bunde et al. (2005) Long-Term Memory: A Natural Mechanism for the Clustering of Extreme Events and Anomalous Residual Times in Climate Records.

Ferguson, R.P. & J. Veizer (2007) Coupling of water and carbon fluxes via the terrestrial biosphere and its significance to the Earth's climate system.- Journal of Geophysical Research, Vol. 112, D24S06, oi:10.1029/2007JD008431, 2007

• Abstract:
  "Terrestrial water vapor fluxes represent one of the largest movements of mass and energy in the Earth's outer spheres, yet the relative contributions of abiotic water vapor fluxes and those that are regulated solely by the physiology of plants remain poorly constrained. By interpreting differences in the oxygen-18 and deuterium content of precipitation and river water, a methodology was developed to partition plant transpiration (T) from the evaporative flux that occurs directly from soils and water bodies (E d ) and plant surfaces (In). The methodology was applied to fifteen large watersheds in North America, South America, Africa, Australia, and New Guinea, and results indicated that approximately two thirds of the annual water flux from the "water-limited" ecosystems that are typical of higher-latitude regions could be attributed to T. In contrast to "water-limited" watersheds, where T comprised 55% of annual precipitation, T in high-rainfall, densely vegetated regions of the tropics represented a smaller proportion of precipitation and was relatively constant, defining a plateau beyond which additional water input by precipitation did not correspond to higher T values. In response to variable water input by precipitation, estimates of T behaved similarly to net primary productivity, suggesting that in conformity with small-scale measurements, the terrestrial water and carbon cycles are inherently coupled via the biosphere. Although the estimates of T are admittedly first-order, they offer a conceptual perspective on the dynamics of energy exchange between terrestrial systems and the atmosphere, where the carbon cycle is essentially driven by solar energy via the water cycle intermediary."

Friis-Christensen, E. & K. Lassen (1991) Length of the solar cycle: an indicator of solar activity closely associated with climate.- Science 254, 698-700.

• Besprechung in NewScientist. Science: Climate change - the solar connection, 23 November 1991 - From New Scientist Print Edition
• Vgl. auch Lassen unten!

• Abstract:
  Since November 1978 a set of total solar irradiance (TSI) measurements from space is available, yielding a time series of more than 25 years. Presently, there are three TSI composites available, called PMOD, ACRIM and IRMB, which are all constructed from the same original data, but use different procedures to correct for sensitivity changes. The PMOD composite is the only one which also corrects the early HF data for degradation. The results from the detailed analysis of the VIRGO radiometry allow a good understanding of the effects influencing the long-term behaviour of classical radiometers in space. Thus, a re-analysis of the behaviour of HF/NIMBUS-7 and ACRIM-I/SMM was indicated. For the former the situation is complicated by the fact that there are no in-flight means to determine changes due to exposure to solar radiation by comparison with a less exposed radiometer on the same spacecraft. The geometry and optical property of the cavity of HF is, however, very similar to the PMO6-type radiometers, so the behaviour of the PMO6V radiometers on VIRGO can be used as a model. ACRIM-I had to be revised mainly due to a henceforth undetected early increase and a more detailed analysis of its degradation. The results are not only important for solar radiometry from space, but they also provide a more reliable TSI during cycle 21. The differences between the revised PMOD composite and the ACRIM and IRMB are discussed by comparison with a TSI reconstruction from Kitt-Peak magnetograms. As the PMOD composite is the only one which has reliable data for cycle 21, the behaviour of the three solar cycles can now be compared and the similarities and differences discussed."
  
  
• Dazu einige Textausschnitte aus dem Magazin DER SPIEGEL vom 06.08.07, S.124-126: "Eichmass der Sonnenkraft - Ein Observatorium in Davos misst die Strahlungsenergie der Sonne ....":

• "Erst in jüngster Zeit hat sich an der Sonne wieder ein erbitterter Streit um eine Schicksalsfrage der Menschheit entzündet: Heizen die Industrieabgase die Erde auf, oder ist daran möglicherweise die Sonne schuld?" (S.124
• "Von der breiten Öffentlichkeit praktisch unbemerkt, gelang dem Institut vor knapp zwei Jahren der erste, direkt gemessene Beweis dafür, dass der Treibhauseffekt auf der Erde tatsächlich zunimmt. Zehn Messstationen, die höchstgelegene davon auf dem ...."
• "Seit fast zwölf Jahren beobachtet es auf der Sonde Soho die Sonne ... Und doch ist den Forschern noch immer vieles, was sich auf der Sonne vollzieht, mysteriös geblieben." (S.125)
• "Die abgestrahlte Energie [der Sonne] variiert. 'Verantwortlich dafür sind Phänomene, die wir grösstenteils beschreiben, aber leider nicht wirklich befriedgend erklären können', so Fröhlich."
• "Über Jahrtausende hin sei die Klimageschichte bestimmt gewesen von unverstandenen Launen der Sonne, sagt Fröhlich. Und das sei ja auch nicht verwunderlich: 'Schliesslich stammen fast hundert Prozent aller Energie auf der Erde von der Sonne.'" (S.126)
• "Wesentlich stärker als die Gesamtstrahlung jedoch verändert sich der ultraviolette Bestandteil des Sonnenlichts. Die Davoser Messgeräte, die ihn aufzeichnen, zeigen ein ungestümes Auf und Ab: 'Die UV-Strahlung schwankt mitunter zehnmal stärker als die Gesamtintensität der Sonne', sagt Direktor Schmutz."
• "Eine dritte Einflussgrösse auf das Erdklima könnte die kosmische Strahlung sein, die aus den Tiefen des Alls stammt. Wie ein Orkan prasseln hochenergetische Protonen auf das Sonnensystem nieder. Geschützt wird die Erde unter anderem vom sogenannten Sonnenwind. Dabei gilt: Je aktiver die Sonne, desto besser schirmt dieser Wind den Globus ab. Ist die Sonne hingegen schwach, so hämmern die kosmischen Teilchen viel stärker auf die Erdatmosphäre ein. Wie genau sich dies aufs Erdklima auswirkt, ist nicht klar...".
  
  
• Und zu den unterschiedlichen Theorien über die Bedeutung der Sonne:
  "Ich bin überzeugt, dass die eine oder die andere Vorhersage der vielen Theorien eintreffen wird", sagt Schmutz, und Fröhlich sekundiert: Ganz genau. Wir wissen eben nur nicht, welche der hundert Theorien es am Ende ist." (S.126)
  
  
• Vgl. Sie dazu auch:
  Thejll & Lassen (2000),
  Marsh & Svensmark (2000 / 2003 / 2006),
  Willson & Mordvinov (2003),
  Svensmark & Friis-Christensen (2007),
  
  sowie die Auseinandersetzung zwischen Svensmark und Laut auf der Website von Stephen H. Schneider mit dem sonderbaren Verständnis von Wissenschaft und der akzeptierten Hockeystick-Kurve,
  
  aber auch die Forschungen um den Heidelberger Prof. Frank Arnold vom MPI für Kernphysik.

• Einführung:
  "Durch menschliche Aktivitäten wird die chemische Zusammensetzung der Atmosphäre verändert und die Oberfläche der Erde umgestaltet. Beides beeinflusst das Klima. So steigen bekanntlich die Konzentrationen klimarelevanter Spurenstoffe deutlich an: z.B. Kohlendioxid im wesentlichen durch das Verbrennen von fossilen Treibstoffen, Methan durch verstärkten Nassreisanbau und durch zunehmende Viehhaltung ,usw. Dieser Anstieg verstärkt den natürlichen Treibhauseffekt und führt zu einer Erwärmung der Troposphäre (vom Boden bis etwa 10 km Höhe) und zu einer Abkühlung der darüber liegenden Stratosphäre (etwa 10 bis 50 km Höhe). Andererseits führt z.B. eine anthropogene (durch Luftverschmutzung) Erhöhung des atmosphärischen Aerosols (kleine Schwefelsäuretröpfchen) regional zu einer Abkühlung der Troposphäre. Zusätzlich zu diesen anthropogenen Einflüssen gibt es natürliche Faktoren, die das Klima beeinflussen und die das Erkennen des vom Menschen verursachten "Klima-Trends" erschweren. Dazu gehören z.B. Vulkaneruptionen, die in unregelmässigen Abständen in das Klimageschehen eingreifen, und die Sonnenaktivität, die besonders im 10-12jährigen Rhythmus Einfluss auf das Klima nimmt. Auf beide Faktoren wird in den nachfolgenden Abbildungen hingewiesen."
  
  Die Abb. zeigt deutlich, "... daß die Temperatur sowohl am Boden (c) wie auch in der Höhe (a und b) parallel zur Sonnenaktivität schwankt: Maxima findet man 1958, 1969, 1980 und 1990, also unabhängig von den Vulkaneruptionen. Die Minima liegen entsprechend dazwischen. Das bedeutet, dass die Trends durch den Einfluss der Sonnenaktivität moduliert werden, wenn man auch den Mechanismus dieses Zusammenhangs bis heute noch nicht genau versteht."

Global 'Sunscreen' Has Likely Thinned, Report NASA Scientists.- Research News, Mar. 15, 2007.

• Textauszug:
  The thinning of Earth’s “sunscreen” of aerosols since the early 1990s could have given an extra push to the rise in global surface temperatures. The finding, published in the March 16 issue of Science, may lead to an improved understanding of recent climate change. In a related study published last week, scientists found that the opposing forces of global warming and the cooling from aerosol-induced "global dimming" can occur at the same time.
  "When more sunlight can get through the atmosphere and warm Earth's surface, you're going to have an effect on climate and temperature," said lead author Michael Mishchenko of NASA's Goddard Institute for Space Studies (GISS), New York. "Knowing what aerosols are doing globally gives us an important missing piece of the big picture of the forces at work on climate."

  vgl. dazu auch:
  Mishchenko et al. 2007;
  Romanou et al. 2007;
  Lau et al. 2006;
  Heitzenberg 2005;
  Govindan et al. 2002;
  Rasool & Schneider 1971:

GKSS - Gesellschaft für Kernenergieverwertung in Schiffbau und Schiffahrt mbH (2004): Auf die Problematik bei der Verwendung von Proxy-Daten als Grundlage der Klimaforschung für bisherige Klimamodelle hat (04.10.2004) Prof. Dr. Hans von Storch, Leiter des Instituts für Küstenforschung des GKSS Forschungszentrums in Geesthacht, hingewiesen. Dies ergibt sich aus der Studie einer internationalen Forschergruppe. [date of access: 04.10.04]

"Das Ergebnis ist von weitreichender Bedeutung, da Temperatur-Rekonstruktionen, die auf Proxy-Daten basieren, benutzt werden, um den Klimawandel der letzten 1.000 Jahre abzuschätzen, besonders durch das Intergovernmental Panel on Climate Change in seinem Third Assessment Report [IPCC 3rd AP] . Die neuen Ergebnisse zeigen, dass solche Rekonstruktionen, die üblicherweise benutzt werden, um die jüngsten extremen Klimaänderungen hervorzuheben, wahrscheinlich irreführend sind. Sie unterschätzen die Temperaturschwankungen von Jahrhunderten möglicherweise ganz erheblich."

Anmerkung:
Verständlicherweise wird Prof. von Storch von Mitgliedern des IPCC heftig kritisiert und seine Auffassung als nicht ernst zu nehmende Minderheitenmeinung dargestellt, z.B. von Prof. Schellnhuber (PIK) in einem Interview am 3. Okt. 2005 (10:45h) im rbb [date of access: 04.10.05] (das nachzulesende Interview wurde leider um die kritischen Bemerkungen - Fachkollegen betreffend - gekürzt).

Global climate models violate scaling of the observed atmospheric variability.

• Abstract:
  "We test the scaling performance of seven leading global climate models by using detrended fluctuation analysis. We analyze temperature records of six representative sites around the globe simulated by the models, for two different szenarios: (i) with greenhouse gas forcing only and (ii) with greenhouse gas plus aerosol forcing. We find that the simulated records for both scenarios fail to reproduce the universal scaling behavior of the observed records and display wide performance differences. The deviations from the scaling behavior are more pronounced in the first scenario, where also the trends are clearly overestimated."

  Vgl. dazu auch
  
  Eichner et al. (2003)
  Bunde et al. (2005)
  GISS 2007 und die folgende Arbeit von Green et al. (2004).

Graßl, H. (1989) Anthropogene Beeinflussung des Klimas.- Physikalische Blätter 45, 199 (1989)

• Statement:
  "Wenn mir vor nur drei Jahren jemand prophezeit hätte, daß ich, ein in die Geowissenschaften abgewanderter Physiker, anläßlich einer Festversammlung der Deutschen Physikalischen Gesellschaft (DPG) über Klimaforschung sprechen würde, hätte ich ihn ungläubig angestarrt. Welche Entwicklung hat das wahr werden lassen?
  • erstens das gigantischste Experiment, das die Menschheit je unternahm;
  • zweitens der Versuch der DPG im Jahre 1986, die bundesrepublikanische Öffentlichkeit mit einer ersten Denkschrift (aus dem Arbeitskreis Energie) zum Thema dieses Vortrags aufzurütteln;
  • drittens die Proteste der „randständigen”? Deutschen Meteorologischen Gesellschaft (DMG);
  • viertens meine von der DMG gewünschte Aufnahme in diesen Arbeitskreis noch im Jahre 1986 und
  • schließlich die zweite, glücklicherweise sehr wirksame, auch von mir mitgestaltete Denkschrift: „Warnung vor drohenden weltweiten Klimaänderungen durch den Menschen”?, die vor zwei Jahren anläßlich der Hauptversammlung der DPG gemeinsam von der DPG und der DMG vorgestellt wurde (Phys. Bl. 43 (1987) Nr. 8, S. 347–349).

Ich möchte Ihnen heute den Stand der Erkenntnis, zu dem jeder von uns Wissenschaftlern nur Mosaiksteinchen hinzufügt, vorstellen, D. H. Ich werde im wesentlichen über die Arbeit von Kollegen berichten. Beginnen werde ich mit der Diskussion der beiden bedeutendsten Klimaparameter, danach stelle ich die Komponenten des Klimasystems vor, nenne die möglichen Pfade zur ungewollten globalen Klimaänderung durch den Menschen, um dann den wichtigsten davon, nämlich die Veränderung der Zusammensetzung der Luft, im Hauptteil des Vortrags ausführlicher zu behandeln."

Green, K.C., J.S. Armstrong and W. Soon (2009) Validity of Climate Change Forecasting for Public Policy Decision Making.- International Journal of Forecasting 25 (2009) 826–832.

• "Abstract
  Policymakers need to know whether prediction is possible and, if so, whether any proposed forecasting method will provide forecasts that are substantially more accurate than those from the relevant benchmark method. An inspection of global temperature data suggests that temperature is subject to irregular variations on all relevant time scales, and that variations during the late 1900s were not unusual.

  In such a situation, a “no change” extrapolation is an appropriate benchmark forecasting method. We used the UK Met Office Hadley Centre’s annual average thermometer data from 1850 through 2007 to examine the performance of the benchmark method. The accuracy of forecasts from the benchmark is such that even perfect forecasts would be unlikely to help policymakers. For example, mean absolute errors for the 20- and 50-year horizons were 0.18 °C and 0.24 °C respectively. We nevertheless demonstrate the use of benchmarking with the example of the Intergovernmental Panel on Climate Change’s 1992 linear projection of long-term warming at a rate of 0.03 °C per year.

  The small sample of errors from ex ante projections at 0.03 °C per year for 1992 through 2008 was practically indistinguishable from the benchmark errors. Validation for long-term forecasting, however, requires a much longer horizon. Again using the IPCC warming rate for our demonstration, we projected the rate successively over a period analogous to that envisaged in their scenario of exponential CO2 growth - the years 1851 to 1975.

  The errors from the projections were more than seven times greater than the errors from the benchmark method. Relative errors were larger for longer forecast horizons. Our validation exercise illustrates the importance of determining whether it is possible to obtain forecasts that are more useful than those from a simple benchmark before making expensive policy decisions."

Green, K.C. & J. S. Armstrong (2007) Global Warming: Forecasts by Scientists versus Scientific Forecasts.- Energy & Environment *), Vol. 18 No. 7+8 2007 (MPRA-Paper No. 4361, posted 07 Aug 2007). [19 S.]
[last date of access: 22.11.2019]

• Abstract:
  “In 2007, the Intergovernmental Panel on Climate Change’s Working Group One, a panel of experts established by the World Meteorological Organization and the United Nations Environment Programme, issued its Fourth Assessment Report. The Report included predictions of dramatic increases in average world temperatures over the next 92 years and serious harm resulting from the predicted temperature increases. Using forecasting principles as our guide we asked: Are these forecasts a good basis for developing public policy? Our answer is “no”.

  To provide forecasts of climate change that are useful for policy-making, one would need to forecast (1) global temperature, (2) the effects of any temperature changes, and (3) the effects of feasible alternative policies. Proper forecasts of all three are necessary for rational policy making.

  The IPCC WG1 Report was regarded as providing the most credible long-term forecasts of global average temperatures by 31 of the 51 scientists and others involved in forecasting climate change who responded to our survey. We found no references in the 1056-page Report to the primary sources of information on forecasting methods despite the fact these are conveniently available in books, articles, and websites. We audited the forecasting processes described in Chapter 8 of the IPCC’s WG1 Report to assess the extent to which they complied with forecasting principles. We found enough information to make judgments on 89 out of a total of 140 forecasting principles. The forecasting procedures that were described violated 72 principles. Many of the violations were, by themselves, critical.

  The forecasts in the Report were not the outcome of scientific procedures. In effect, they were the opinions of scientists transformed by mathematics and obscured by complex writing. Research on forecasting has shown that experts’ predictions are not useful in situations involving uncertainly and complexity. We have been unable to identify any scientific forecasts of global warming. Claims that the Earth will get warmer have no more credence than saying that it will get colder.”

  *) Energy & Environment is NOT a peer-reviewed science publication!

Green, J.L. et al. (2005) Eyewitness Reports of the Great Auroral Storm of 1859.- Submitted to Advances in Space Research (NASA Techn. Reports). 35 S.

Besuchen Sie zu diesem Ereignis die entsprechende Seite in Wikipedia: Carrington Event
[date of access: 21.12.2020]

Grinsted, A., Moore, J.C., Pohjola, V., Martma, T. and Isaksson, E. (2006) Svalbard summer melting, continentality, and sea ice extent from the Lomonosovfonna ice core.- Journal of Geophysical Research, 111, 10.1029/2005JD006494.

• Abstract:
  "We develop a continentality proxy (1600–1930) based on amplitudes of the annual signal in oxygen isotopes in an ice core. We show via modeling that by using 5 and 15 year average amplitudes the effects of diffusion and varying layer thickness can be minimized, such that amplitudes then reflect real seasonal changes in δ¹⁸O under the influence of melt. A model of chemical fractionation in ice based on differing elution rates for pairs of ions is developed as a proxy for summer melt (1130–1990). The best pairs are sodium with magnesium and potassium with chloride. The continentality and melt proxies are validated against twentieth-century instrumental records and longer historical climate proxies. In addition to summer temperature, the melt proxy also appears to reflect sea ice extent, likely as a result of sodium chloride fractionation in the oceanic sea ice margin source area that is dependent on winter temperatures. We show that the climate history they depict is consistent with what we see from isotopic paleothermometry. Continentality was greatest during the Little Ice Age but decreased around 1870, 20–30 years before the rise in temperatures indicated by the δ¹⁸O profile. The degree of summer melt was significantly larger during the period 1130–1300 than in the 1990s."

Hathaway, David H. & Lisa Rightmire (2010) Variations in the Sun's Meridional Flow over a Solar Cycle.- Science Vol. 327. no. 5971, pp. 1350 - 1352, DOI: 10.1126/science.1181990 (12 March 2010)

• Abstract:
  "The Sun's meridional flow is an axisymmetric flow that is generally directed from its equator toward its poles at the surface. The structure and strength of the meridional flow determine both the strength of the Sun's polar magnetic field and the intensity of sunspot cycles. We determine the meridional flow speed of magnetic features on the Sun using data from the Solar and Heliospheric Observatory. The average flow is poleward at all latitudes up to 75°, which suggests that it extends to the poles. It was faster at sunspot cycle minimum than at maximum and substantially faster on the approach to the current minimum than it was at the last solar minimum. This result may help to explain why this solar activity minimum is so peculiar."

• Abstract:
  "The magnitude and impact of future global warming depends on the sensitivity of the climate system to changes in greenhouse gas concentrations. The commonly accepted range for the equilibrium global mean temperature change in response to a doubling of the atmospheric carbon dioxide concentration1, termed climate sensitivity, is 1.5–4.5 K (ref. 2). A number of observational studies (...), however, find a substantial probability of significantly higher sensitivities, yielding upper limits on climate sensitivity of 7.7 K to above 9 K (refs 3–8). Here we demonstrate that such observational estimates of climate sensitivity can be tightened if reconstructions of Northern Hemisphere temperature over the past several centuries are considered. We use large-ensemble energy balance modelling and simulate the temperature response to past solar, volcanic and greenhouse gas forcing to determine which climate sensitivities yield simulations that are in agreement with proxy reconstructions. After accounting for the uncertainty in reconstructions and estimates of past external forcing, we find an independent estimate of climate sensitivity that is very similar to those from instrumental data. If the latter are combined with the result from all proxy reconstructions, then the 5–95 per cent range shrinks to 1.5–6.2 K, thus substantially reducing the probability of very high climate sensitivity."

• Abstract:
  "Whether the North Atlantic Ocean is warming or cooling is an important question both in physical oceanography and climate change. The Argo profiling buoys provide an accurate and stable instrument for determining the tendencies in heat content from the surface to 2000 m from 1999 to 2005. To calculate temperature and heat content anomalies two reference climatologies are used. These are the well known WOA2001 climatology (Stephens et al., 2002), and a new WOCE Global Hydrographic climatology (Gouretski and Koltermann, 2004). The former climatology is used for our main results, and the latter is used for evaluating the sensitivity of our results to the climatology. Our scheme allows us to estimate the anomaly of heat content (AHC) in the North Atlantic and its smaller sub-domains (i.e. 10° boxes) for the period 1999–2005. We have found a dipole structure in the time averaged AHC: negative values are concentrated in the southern and middle latitudes of the North Atlantic whilst positive values are found north of 50°N. The upper 1500 m of the North Atlantic is warming throughout the period 1999 to 2005."

Karlén, Wibjorn (1998) Climate variations and the enhanced greenhouse effect.- Ambio, Royal Swedish Academy of Sciences.

• Abstract:
  "Changes in the size of glaciers, in the altitude of the alpine tree-limit, and variation in the width of tree-rings during the Holocene clearly indicate that the average Scandinavian summer temperature has fluctuated. During warm periods it has been about 2°C warmer than at present; during cold periods it has been almost as cold as it was during the coldest decades of the previous centuries. Superimposed on these long-term variations, which have lasted from 100 to 200 years, are short fluctuations in temperature. The Scandinavian chronology, which is based on glacier and alpine tree-limit fluctuations as well as on dendrochronology, is well correlated with the changes in climate, which studies of ice cores from central Greenland have revealed. It is therefore believed that the Scandinavian climate chronology depicts conditions typical of a large area. The Scandinavian record is compared with data concerning solar irradiation variations estimated as 14 C anomalies obtained from tree-rings. A correlation between major changes in climate and variations in solar irradiation points to a solar forcing of the climate. This means that there is no evidence of a human influence on climate so far."

Keenlyside, N. S., M. Latif, J. Jungclaus, L. Kornblueh, and E. Roeckner (2008) Advancing Decadal-Scale Climate Prediction in the North Atlantic Sector.- Nature, 453, 84-88.

• Abstract:
  " The climate of the North Atlantic region exhibits fluctuations on decadal timescales that have large societal consequences. Prominent examples include hurricane activity in the Atlantic, and surface-temperature and rainfall variations over North America, Europe and northern Africa. Although these multidecadal variations are potentially predictable if the current state of the ocean is known, the lack of subsurface ocean observations that constrain this state has been a limiting factor for realizing the full skill potential of such predictions. Here we apply a simple approach - that uses only sea surface temperature (SST) observations - to partly overcome this difficulty and perform retrospective decadal predictions with a climate model. Skill is improved significantly relative to predictions made with incomplete knowledge of the ocean state, particularly in the North Atlantic and tropical Pacific oceans. Thus these results point towards the possibility of routine decadal climate predictions.

  Using this method, and by considering both internal natural climate variations and projected future anthropogenic forcing, we make the following forecast: over the next decade, the current Atlantic meridional overturning circulation will weaken to its long-term mean; moreover, North Atlantic SST and European and North American surface temperatures will cool slightly, whereas tropical Pacific SST will remain almost unchanged. Our results suggest that global surface temperature may not increase over the next decade, as natural climate variations in the North Atlantic and tropical Pacific temporarily offset the projected anthropogenic warming."
  
  Literaturangaben wurden nicht berücksichtigt!

Keppler, F., John T. G. Hamilton, M. Braß & Th. Röckmann (2006) Methane emissions from terrestrial plants under aerobic conditions.- Nature 439, 187-191 (12 January 2006).

• Abstract:
  "Methane is an important greenhouse gas and its atmospheric concentration has almost tripled since pre-industrial times1, 2. It plays a central role in atmospheric oxidation chemistry and affects stratospheric ozone and water vapour levels. Most of the methane from natural sources in Earth's atmosphere is thought to originate from biological processes in anoxic environments2. Here we demonstrate using stable carbon isotopes that methane is readily formed in situ in terrestrial plants under oxic conditions by a hitherto unrecognized process. Significant methane emissions from both intact plants and detached leaves were observed during incubation experiments in the laboratory and in the field. If our measurements are typical for short-lived biomass and scaled on a global basis, we estimate a methane source strength of 62–236 Tg yr-1 for living plants and 1–7 Tg yr-1 for plant litter (1 Tg = 1012 g). We suggest that this newly identified source may have important implications for the global methane budget and may call for a reconsideration of the role of natural methane sources in past climate change."
  
• Besprechung im Rhombos Verlag: Die vergessene Methan-Quelle [Besprechung leider nicht mehr online] - vgl. auch SdW Mai 2007: 68-73.
• Anmerkung:
  Sollten die o.g. Ergebnisse zutreffen, wird das bisherige Lehrbuchwissen bzgl. nicht möglicher Methanabgabe durch lebende Pflanzen obsolet. Darüber hinaus sind die bisherigen Klimamodelle neu zu rechnen, da Methan als interaktivem Treibhausgas (20-30x wirksamer als Kohlendioxid) eine wesentliche Rolle im Wechselspiel der unterschiedlichen Treibhausgasquellen (speziell Kohlendioxid) zukommt.

• Abstract:
  " The authors identify and describe the following global forces of nature driving the Earth’s climate: (1) solar radiation as a dominant external energy supplier to the Earth, (2) outgassing as a major supplier of gases to the World Ocean and the atmosphere, and, possibly, (3) microbial activities generating and consuming atmospheric gases at the interface of lithosphere and atmosphere. The writers provide quantitative estimates of the scope and extent of their corresponding effects on the Earth’s climate. Quantitative comparison of the scope and extent of the forces of nature and anthropogenic influences on the Earth’s climate is especially important at the time of broad-scale public debates on current global warming. The writers show that the human-induced climatic changes are negligible."

• Abstract:
  "The purpose of this paper is to put forward a new estimate, in the context of previous assessments, of the annual global mean energy budget. A description is provided of the source of each component to this budget. The top-of-atmosphere shortwave and longwave flux of energy is constrained by satellite observations. Partitioning of the radiative energy throughout the atmosphere is achieved through the use of detailed radiation models for both the longwave and shortwave spectral regions. Spectral features of shortwave and longwave fluxes at both the top and surface of Earth's system are presented. The longwave radiative forcing of the climate system for both clear (125 W·m-2) and cloudy (155 W·m-2) conditions are discussed. We find that for the clear sky case the contribution due to water vapor to the total longwave radiative forcing is 75 W·m-2, while for carbon dioxide it is 32 W·m-2. Clouds alter these values, and the effects of clouds on both the longwave and shortwave budget are addressed. In particular, the shielding effect by clouds on absorption and emission by water vapor is as large as the direct cloud forcing. Because the net surface heat budget must balance, the radiative fluxes constrain the sum of the sensible and latent heat fluxes which can also be estimated independently."
  Vgl. dazu auch Treibhauseffekt

Kirkby, J. (2007) Cosmic Rays and Climate.- Surveys in Geophysics 28, 333-375. (Full article CERN-PH-EP/2008-005, 26 March 2008) 44 S. [date of access: 08.12.09]

• Abstract:
  "Among the most puzzling questions in climate change is that of solar-climate variability, which has attracted the attention of scientists for more than two centuries. Until recently, even the existence of solar-climate variability has been controversial-perhaps because the observations had largely involved correlations between climate and the sunspot cycle that had persisted for only a few decades. Over the last few years, however, diverse reconstructions of past climate change have revealed clear associations with cosmic ray variations recorded in cosmogenic isotope archives, providing persuasive evidence for solar or cosmic ray forcing of the climate. However, despite the increasing evidence of its importance, solar-climate variability is likely to remain controversial until a physical mechanism is established. Although this remains a mystery, observations suggest that cloud cover may be influenced by cosmic rays, which are modulated by the solar wind and, on longer time scales, by the geomagnetic field and by the galactic environment of Earth. Two different classes of microphysical mechanisms have been proposed to connect cosmic rays with clouds: firstly, an influence of cosmic rays on the production of cloud condensation nuclei and, secondly, an influence of cosmic rays on the global electrical circuit in the atmosphere and, in turn, on ice nucleation and other cloud microphysical processes. Considerable progress on understanding ion-aerosol-cloud processes has been made in recent years, and the results are suggestive of a physically-plausible link between cosmic rays, clouds and climate. However, a concerted effort is now required to carry out definitive laboratory measurements of the fundamental physical and chemical processes involved, and to evaluate their climatic significance with dedicated field observations and
  modelling studies."
  

Knutti, Reto (2010)The end of model democracy? - An editorial comment.- Climatic Change, DOI 10.1007/s10584-010-9800-2.
10S. [date of access: 21.04.10]

• Auszug (S. 4):
  
  " 2.3 ‘All models are wrong’, or the issue of structural uncertainty.
  The fact that no parameter set in a model matches all observations means that the model is structurally wrong, i.e. there are processes that are not adequately resolved or parameterized, or missing entirely (Kennedy and O’Hagan 2001; McWilliams 2007; Smith 2002). Incorporating structural uncertainty (or model discrepancy) in an uncertainty analysis is a tough problem. Some argue that structural problems are too big compared to the observational uncertainty, implying that all models are so wrong that we cannot even attach likelihoods to models (Stainforth et al. 2007). I would not go that far. All models can be shown to be inaccurate to some degree if we use enough data to evaluate them. But this may not matter in some cases, and is expected because a model is only an approximate description of the real system ...".
  
  
• Prof. Knutti (ETH Zürich, Institute for Atmospheric and Climate Science) hält die AGW-Hypothese für zutreffend. Zitat: "Even if carbon emissions were instantly reduced to zero, most of the climate change that has occurred is irreversible for a thousand years. While some impacts are still uncertain, there are robust predictions for both short term impacts like droughts and long term effects like sea level rise."

Koutsoyiannis, D., A. Efstratiadis, N. Mamassis, and A. Christofides (2008) On the credibility of climate predictions.- Hydrological Sciences Journal, 53 (4), 671–684.

• Auszug:
  "At the annual and the climatic (30-year) scales, GCM interpolated series are irrelevant to reality. GCMs do not reproduce natural over-year fluctuations and, generally, underestimate the variance and the Hurst coefficient of the observed series. Even worse, when the GCM time series imply a Hurst coefficient greater than 0.5, this results from a monotonic trend, whereas in historical data the high values of the Hurst coefficient are a result of large-scale over-year fluctuations (i.e. successions of upward and downward ‘trends’. The huge negative values of coefficients of efficiency show that model predictions are much poorer than an elementary prediction based on the time average. This makes future climate projections at the examined locations not credible."
• Abstract:
  "Geographically distributed predictions of future climate, obtained through climate models, are widely used in hydrology and many other disciplines, typically without assessing their reliability. Here we compare the output of various models to temperature and precipitation observations from eight stations with long (over 100 years) records from around the globe. The results show that models perform poorly, even at a climatic (30-year) scale. Thus local model projections cannot be credible, whereas a common argument that models can perform better at larger spatial scales is unsupported." ITIA Research Team

(2005) On the Solar Cycle-QBO-Relationship: A Summary.- J.A.S.-T.P., special issue, 67, 45-54.

• Abstract:
  "We have shown in several publications that there exists a strong signal of the 11-year sunspot cycle throughout the year, but this signal can only be identified, if the data are stratified according to the phase of the QBO (Labitzke, 1987; 2002, 2003; Labitzke and van Loon, 1988, 2000; van Loon and Labitzke, 1994, 2000). The 11-year sunspot cycle is connected with a large variability of the solar radiation in the ultraviolet (UV) part of the spectrum which varies about 6-8% between solar maxima and minima (Chandra and McPeters, 1994). That is enough to cause in the upper stratosphere changes in the temperatures, winds and ozone which will result in circulation changes here and it is possible that such changes have an indirect effect on the lower stratosphere and on the troposphere.
  Different observations indicate that the mean meridional circulation systems, like the Brewer-Dobson Circulation (BDC) and the Hadley Circulation (HC) are influenced by the 11-year solar cycle (Kodera and Kuroda, 2002; Hood and Soukharev, 2003; Labitzke, 2003, 2004a, b; Salby and Callaghan, 2004; van Loon and Meehl, 2004).
  Recent simulations of the middle atmosphere, using General Circulation Models (GCMs) and introducing the changes in UV and ozone and profiles of the winds over the equator, simulating the east and west phase of the QBO, respectively, resulted in a realistic simulation of the variability of the arctic polar vortex in northern winters (e.g., Matthes et al., 2004). The simulated signal over the tropics is, however, still too weak."

Labitzke, K. (1995) Aspekte des Ozonproblems.- Forschung an der Freien Universität Berlin.- Forschung an der Freien Universität Berlin, Referat Forschungsinformation - 3/95-VI C-Labitzk1, Faltblatt, 1995

• Einführung:
  "In fast jeder Diskussion über Umweltprobleme, ob Treibhauseffekt, Grundwasserverschmutzung oder Überschwemmungen, fällt früher oder später das Wort "Ozonloch" - jeder Laie benutzt es mit einer verblüffenden Selbstverständlichkeit. Obwohl er kaum wissen kann, was sich hinter dem Wort "Ozonloch" wirklich verbirgt, fühlt er sich laut Meinungsumfragen (in Deutschland) im Vergleich zu allen anderen Umweltproblemen von dem Ozonloch am meisten bedroht. Und manche Presseberichte schüren diese Angst, indem gelegentlich im Winter vollkommen unsachgemäß and falsch von einem Ozonloch über Deutschland berichtet wird.
  In der Wirklichkeit handelt es sich um einen besorgniserregenden langfristigen, bis in die Mitte des nächsten Jahrhunderts andauernden Abbau des Ozons (siehe Abbildung 2, der durch die Fluorchlorkohlenwasserstoffe (FCKWs), aber auch durch den Anstieg anderer anthropogener Spurenstoffe verursacht wird. Deshalb wurden Maßnahmen ergriffen, um die Produktion und den Verbrauch dieser gefährlichen Produkte weitgehend zu stoppen.
  Es muß aber auch klargestellt werden, daß sich auf der Nordhemisphäre bis jetzt kein "Ozonloch" ausbilden kann, so daß in Deutschland während des ganzen Jahres vor den Sonnenstrahlen keine Angst herrschen muß, wenn man sich gegen Sonnenbrand schützt - wie es auch früher üblich war. Wirklich vorsichtig muß man bei allen Reisen in den Süden sein."

Labitzke, K., M. Kunze, and S. Brönnimann (2006) Sunspots, the QBO, and the Stratosphere in the North Polar Region 20 Years later.- Meteorologische Zeitschrift, Vol. 15, No. 3, 355-363(9)

• Zusammenfassung:
  "In früheren Arbeiten haben wir gezeigt, wie groß der Einfluss des 11-jährigen Sonnenfleckenzyklus auf die untere Stratosphäre ist. Um diesen Einfluss zu isolieren, müssen die Daten nach der Phase der Quasi-Biennial Oscillation (QBO) sortiert werden. Dies ist während des ganzen Jahres notwendig, aber der Einfluss von QBO und 11-jährigem Sonnenfleckenzyklus ist am stärksten während des Nordwinters (Januar-Februar). Für unsere erste Veröffentlichung (Labitzke 1987) standen nur Daten von 30 Jahren zur Verfügung. Aber inzwischen können wir Ergebnisse zeigen, die auf 65 Jahren basieren und die unsere frühen Arbeiten bestätigen: Der 11-jährige Sonnenfleckenzyklus hat einen signifikanten Einfluss auf die Stärke des stratosphärischen Polarwirbels und auf die mittlere Meridionalzirkulation."
  
  vgl. auch: (047) Geb, M. & K. Labitzke (1995)

Landsea, C.W., N. Nicholls, W.M. Gray, and L.A. Avila, (1996) Downward trends in the frequency of intense Atlantic hurricanes during the past five decades.- Geo. Res. Letters, 23, 1697-1700.

• Abstract
  There is concern that the enhanced greenhouse effect may be affecting extreme weather events such as tropical cyclones. The North Atlantic basin offers a reliable, long-term record of tropical cyclone activity, though it may not be representative of tropical cyclones throughout the rest of the tropics. The most recent years of 1991 through 1994 have experienced the quietest tropical cyclone activity on record in terms of frequency of tropical storms, hurricanes, and intense hurricanes. This was followed by the 1995 hurricane season, one of the busiest in the past 50 years. Despite 1995's activity, a long-term (five decade) downward trend continues to be evident primarily in the frequency of intense hurricanes. In addition, the mean maximum intensity (i.e., averaged over all cyclones in a season) has decreased, while the maximum intensity attained by the strongest hurricane each year has not shown a significant change.
  Recent Publications of Landsea and others, and Submissions.

Lassen, K. (1997 ?) Solar Activity and Climate - Long-term Variations in Solar Activity and their Apparent Effect on the Earth's Climate.- Danish Meteorological Institute, Solar-Terrestrial Physics Division, Lyngbyvej,100, DK-2100 Copenhagen (2), Denmark.

• Abstract
  "The varying length of the 11-year cycle has been found to be strongly correlated with longterm variations of the northern hemisphere land surface air temperature since the beginning of systematic temperature variations from a global network, i. e. during the past 130 years. Although direct temperature observations before this interval are scarce, it has been possible to extend the correlation back to the 16th century due to the existence of a series of proxy temperature data published by Groveman and Landsberg in 1979. Reliable sunspot data do not exist before 1750, but we have been able to derive epochs of minimum sunspot activity from auroral observations back to 1500 and combine them with the direct observations to a homogeneous series.
  Comparison of the extended solar activity record with the temperature series confirms the high correlation between solar activity and northern hemisphere land surface air temperature and shows that the relationship has existed through the whole 500-year interval for which reliable data exist.
  A corresponding influence of solar activity has been demonstrated in other climatic parameters. Thus, both the date of arrival of spring in the Yangtze River Valley as deduced from phenological data and the extent of the sea-ice in the Atlantic sector of the Arctic sea have been shown to be correlated with the length of the sunspot cycle during the last 450 years."

• Vgl. dazu auch GISS 2007.

Lockwood, M. & C. Fröhlich , J. (2007) Recent oppositely directed trends in solar climate forcings and the global mean surface
air temperature.- 14 S. Proc. R. Soc. A, doi:10.1098/rspa.2007.1880 Published online. [date of access: 21.04.08]

• "There is considerable evidence for solar influence on the Earth’s pre-industrial climate and the Sun may well have been a factor in post-industrial climate change in the first half of the last century. Here we show that over the past 20 years, all the trends in the Sun that could have had an influence on the Earth’s climate have been in the opposite direction to that required to explain the observed rise in global mean temperatures."
  
  
• Eine sehr beachtenswerte und kritische Analyse dieser Arbeit durch Nir Shaviv finden Sie hier: Why is Lockwood and Fröhlich meaningless?
• Eine sofortige Reaktion auf diese Arbeit gaben auch Henrik Svensmark and Eigil Friis-Christensen ab.

• Abstract:
  "European monthly temperatures undergo strong fluctuations from one year to the other. The variability is controlled by natural processes such as Atlantic cycles, changes in solar activity, volcanic eruptions, unforced internal atmospheric variability, as well as anthropogenic factors. This contribution investigates the role of key natural drivers for European temperature variability, namely the Atlantic Multidecadal Oscillation (AMO), the North Atlantic Oscillation (NAO) and solar activity changes. We calculated Pearson correlation coefficients r for AMO, NAO and sunspots compared to monthly temperature data of 39 European countries for the period
  1901–2015 in order to search for ‘fingerprints’ of the natural drivers. A cross correlation window of 11 months was chosen for AMO, NAO and of 120 months for SILSO to account for possible time lags or phase shifts. The r coefficients were mapped out across Europe on a monthly basis to document regional and seasonal changes of the correlation strength. The NAO dominates European temperature variability during the winter months, with strongest relationship in February. The AMO modulates temperatures in March to November, with best correlations
  occurring in summer, but also in April. Regions of strongest AMO and NAO impacts shift across the continent from month to month, forming systematic patterns. Direct correlation of the solar 11-year Schwabe cycle with temperatures was identified only in some countries in certain multidecadal intervals during February, March, June and September. Previous studies have suggested a significant solar influence on the AMO and NAO. It is likely that the greatest impact of solar activity on European temperatures is of a non-linear, indirect nature by way of interaction with Atlantic cycles."
  

• Abstract:
  " On short (15-year) to mid-term (30-year) time-scales how the Earth’s surface temperature evolves can be dominated by internal variability as demonstrated by the global-warming pause or ‘hiatus’. In this study, we use six single model initial-condition large ensembles (SMILEs) and the Coupled Model Intercomparison Project 5 (CMIP5) to visualise the role of internal variability in controlling possible observable surface temperature trends in the short-term and mid-term projections from 2019 onwards. We confirm that in the short-term, surface temperature trend projections are dominated by internal variability, with little influence of structural model differences or warming pathway. Additionally we demonstrate that this result is independent of the model-dependent estimate of the magnitude of internal variability. Indeed, and perhaps counter intuitively, in all models a lack of warming, or even a cooling trend could be observed at all individual points on the globe, even under the largest greenhouse gas emissions. The near-equivalence of all six SMILEs and CMIP5 demonstrates the robustness of this result to the choice of models used. On the mid-term time-scale, we confirm that structural model differences and scenario uncertainties play a larger role in controlling surface temperature trend projections than they did on the shorter time-scale.In addition we show that whether internal variability still dominates, or whether model uncertainties and internal variability are a similar magnitude, depends on the estimate of internal variability, which differs between the SMILEs. Finally we show that even out to thirty years large parts of the globe (or most of the globe in MPI-GE and CMIP5) could still experience no-warming due to internal variability."

• Besprechung von Uwe Goerlitz in GeoWiss.de > [leider nicht mehr online am 20.11.2019, kann jedoch über archive.org aufgerufen werden] "Klimawandel ist das Normale" (2007-04-07) [last date of access: 05.07.2020]
  
  Ausschnitt:
  
  "Malberg * behandelt alle relevanten Themen der Materie: Atmosphäre, Strahlung, Luftbewegung, Wolkenbildung und Niederschlag, Luftmassen, Zonen und Fronten, Wetter- und Klimabeobachtung, Wetterprognosen und Prognosemodelle, atmosphärische Zirkulationen, Klimaklassifikationen, -schwankungen und -änderungen, lokales Klima, anthropogene Wetterbeeinflussung und Luftverunreinigung.
  
  Gerade Letzeres - Anthropogenes - bestimmt die seit Jahren aktuelle, nunmehr durch den UN-Klimabericht wieder an Wichtigkeit zugenommene und an Kontroversen reiche Debatte. Beim Klimawandel, den der Autor als etwas Normales betrachtet, gestützt auf Messreihen und paläoklimatische Ergebnisse - das liest sich deutlich aus diesem Buch heraus - zählen nicht etwaige Empfindungen, wahlperiodisch oder journalistisch vorgetragenes Halbwissen oder bestürzend lächerlich wirkender Aktionsmus mit angezogener Handbremse, sondern Daten und Fakten."
  
  * Prof. Horst Malberg, Emeritus (2004), ehemaliger Direktor des Instituts für Meteorologie an der FU Berlin.

Malberg, H. (2007) Über den solaren Einfluss auf den Klimawandel seit 1701 - Kritische Anmerkungen zum UN – Klimabericht 2007, ein Beitrag im Internet.

• Achtung!
  Prof. Malberg, ehem. Direktor des Met. Inst. der FU-Berlin, ist zwar ausgewiesener und anerkannter Fachwissenschaftler, aber er ist "leider" emeritiert, zu allem Überfluss auch noch ein Kritiker der IPCC-Katastrophen-Hypothesen und damit nach Lesart von Rahmstorf und Co. eigentlich nicht mehr ernst zu nehmen ... weil nicht mehr zeitgemäss?

Marcott, G.S.A., J.D. Shakun, P.U. Clark and .C. Mix (2013) A Reconstruction of Regional and Global Temperature for the Past 11,300 Years.- Science 08 Mar 2013: Vol. 339, Issue 6124, pp. 1198-1201 DOI: 10.1126/science.1228026. [date of access: 10.04.19]

Abstract:
"Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ~2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios."

Marsh N.D. and H. Svensmark (2003) Solar Influence on Earth's Climate.- Space Science Reviews, Volume 107, Numbers 1-2 / April 2003.

ABSTRACT:
"An increasing number of studies indicate that variations in solar activity have had a significant influence on Earth's climate. However, the mechanisms responsible for a solar influence are still not known. One possibility is that atmospheric transparency is influenced by changing cloud properties via cosmic ray ionisation (the latter being modulated by solar activity). Support for this idea is found from satellite observations of cloud cover. Such data have revealed a striking correlation between the intensity of galactic cosmic rays (GCR) and low liquid clouds (<3.2 km). GCR are responsible for nearly all ionisation in the atmosphere below 35 km. One mechanism could involve ion-induced formation of aerosol particles (diameter range, 0.001–1.0 ?m) that can act as cloud condensation nuclei (CCN). A systematic variation in the properties of CCN will affect the cloud droplet distribution and thereby influence the radiative properties of clouds. If the GCR-Cloud link is confirmed variations in galactic cosmic ray flux, caused by changes in solar activity and the space environment, could influence Earth's radiation budget."

This revised version was published online in August 2006 with corrections to the Cover Date.

Martin-Puertas, C. et al. (2012)Regional atmospheric circulation shifts induced by a grand solar minimum.- Nature Geoscience, Year published: (2012) DOI: doi:10.1038/ngeo1460. [date of access: 07.05.12]

• Abstract:
  "Large changes in solar ultraviolet radiation can indirectly affect climate by inducing atmospheric changes. Specifically, it has been suggested that centennial-scale climate variability during the Holocene epoch was controlled by the Sun. However, the amplitude of solar forcing is small when compared with the climatic effects and, without reliable data sets, it is unclear which feedback mechanisms could have amplified the forcing. Here we analyse annually laminated sediments of Lake Meerfelder Maar, Germany, to derive variations in wind strength and the rate of 10Be accumulation, a proxy for solar activity, from 3,300 to 2,000 years before present. We find a sharp increase in windiness and cosmogenic 10Be deposition 2,759 ± 39 varve years before present and a reduction in both entities 199 ± 9 annual layers later. We infer that the atmospheric circulation reacted abruptly and in phase with the solar minimum. A shift in atmospheric circulation in response to changes in solar activity is broadly consistent with atmospheric circulation patterns in long-term climate model simulations, and in reanalysis data that assimilate observations from recent solar minima into a climate model. We conclude that changes in atmospheric circulation amplified the solar signal and caused abrupt climate change about 2,800 years ago, coincident with a grand solar minimum."

Maslin, M. & P. Austin (2012) Uncertainty: Climate models at their limit? - Nature 486, 183–184 (14 June 2012), doi:10.1038/486183a.

• Remarks:
  "For the fifth major assessment of climate science by the Intergovernmental Panel on Climate Change (IPCC), due to be released next year, climate scientists face a serious public-image problem. The climate models they are now working with, which make use of significant improvements in our understanding of complex climate processes, are likely to produce wider rather than smaller ranges of uncertainty in their predictions. To the public and to policymakers, this will look as though the scientific understanding of climate change is becoming less, rather than more, clear." (by CNAP/CCCC Reading Room). [date of access: 21.03.2013]

McCracken, F.B. McDonald, J. Beer, J. Abreu & F. Steinhilber (2009) The effects of low solar activity upon the cosmic radiation and the interplanetary magnetic field over the past 10,000 years, and implications for the future.

• AGU Fall Meeting, 14 - 18 Dec. 2009, San Francisco, USA, Lecture U34A: "Consequences of an unusually long and deep solar minimum I" [date of access: 22.02.2010]

Meehl, Gerald A., Warren M. Washington, William D. Collins, Julie M. Arblaster, Aixue Hu, Lawrence E. Buja, Warren G. Strand, Haiyan Teng (2005) How Much More Global Warming and Sea Level Rise? - Science 18 March 2005:
Vol. 307. no. 5716, pp. 1769 - 1772, DOI: 10.1126/science.1106663.

• Abstract
  " Two global coupled climate models show that even if the concentrations of greenhouse gases in the atmosphere had been stabilized in the year 2000, we are already committed to further global warming of about another half degree and an additional 320% sea level rise caused by thermal expansion by the end of the 21st century. Projected weakening of the meridional overturning circulation in the North Atlantic Ocean does not lead to a net cooling in Europe. At any given point in time, even if concentrations are stabilized, there is a commitment to future climate changes that will be greater than those we have already observed."

Moberg, A., D.M. Sonechkin, K. Holmgren, N. Datsenko & W. Karlén (2005) Highly Variable Northern Hemisphere Temperatures reconstructed from low- and high-resolution proxy data.- Nature, Vol. 433, No. 7026, pp.. 613-617, 10 February 2005.

• ABSTRACT:
  "A number of reconstructions of millennial-scale climate variability have been carried out in order to understand patterns of natural climate variability, on decade to century timescales, and the role of anthropogenic forcing. These reconstructions have mainly used tree-ring data and other data sets of annual to decadal resolution. Lake and ocean sediments have a lower time resolution, but provide climate information at multicentennial timescales that may not be captured by tree-ring data. Here we reconstruct Northern Hemisphere temperatures for the past 2,000 years by combining low-resolution proxies with tree-ring data, using a wavelet transform technique to achieve timescale-dependent processing of the data. Our reconstruction shows larger multicentennial variability than most previous multi-proxy reconstructions, but agrees well with temperatures reconstructed from borehole measurements and with temperatures obtained with a general circulation model. According to our reconstruction, high temperatures - similar to those observed in the twentieth century before 1990- occurred around AD 1000 to 1100, and minimum temperatures that are about 0.7K below the average of 1961-90 occurred around AD 1600. This large natural variability in the past suggests an important role of natural multicentennial variability that is likely to continue."
  
  Download data from the WDC Paleo archive:
  2,000-Year Northern Hemisphere Temperature Reconstruction.
  Grafik dazu auf der Seite "2000 Jahre Temperaturentwicklung"

Mörner, Nils-Axel (2004) Estimating future sea level changes from past records.- Global and Planetary Change, Volume 40, Issues 1-2, January 2004, Pages 49-54, Global Climate Changes during the Late Quaternary.

• Abstract:
  "In the last 5000 years, global mean sea level has been dominated by the redistribution of water masses over the globe. In the last 300 years, sea level has been oscillation close to the present with peak rates in the period 1890–1930. Between 1930 and 1950, sea fell. The late 20th century lack any sign of acceleration. Satellite altimetry indicates virtually no changes in the last decade. Therefore, observationally based predictions of future sea level in the year 2100 will give a value of +10±10 cm (or +5±15 cm), by this discarding model outputs by IPCC as well as global loading models. This implies that there is no fear of any massive future flooding as claimed in most global warming scenarios."

Mudelsee, M., M. Börngen, G.Tetzlaff & Grünewald U. (2003) No upward trends in the occurrence of extreme floods in central Europe. 4 Seiten - Nature 425:166–169.

• Zusammenfassung der Ergebnisse in InnovationsReport vom 17. Sept. 2003

• Abstract:
  A compilation of paleoclimate records from lake sediments, trees, glaciers, and marine sediments provides a view of circum-Arctic environmental variability over the last 400 years. From 1840 to the mid-20th century, the Arctic warmed to the highest levels in four centuries. This warming ended the Little Ice Age in the Arctic and has caused dramatic retreats of glaciers, melting of permafrost and sea-ice, and alteration of terrestrial and lake ecosystems. Although significant warming, particularly after 1920, was likely due to increases in atmospheric trace-gases, the initiation of the warming in the mid-19th century suggests that increased solar irradiance, decreased volcanic activity, and feedbacks internal to the climate system played roles."
  (with linked site map, individual time series, circum-artic vs forcing, limnological change)
  Source: NOAA-Palaeoclimatology Program - [last date of access: 26.04.07]

Pansegrau, Petra (2000) "Klimaszenarien, die einem apokalyptischen Bilderbogen gleichen“ oder „Leck im Raumschiff Erde“.

• Eine Untersuchung der kommunikativen und kognitiven Funktionen von Metaphorik im Wissenschaftsjournalismus anhand der Spiegelberichterstattung zum "Anthropogenen Klimawandel", Dissertation, Universität Bielefeld, Fak. f. Linguistik und Literaturwissenschaft. [last date of access: 26.04.07]

Pazur, A. & M. Winklhofer (2008) Magnetic effect on CO2 solubility in seawater: A possible link between geomagnetic field variations and climate.- Geophys. Res. Lett., 35, L16710, doi:10.1029/2008GL034288 (30 August 2008) -

• Abstract -
  "Correlations between geomagnetic-field and climate parameters have been suggested repeatedly, but possible links are controversially discussed. Here we test if weak (Earth-strength) magnetic fields can affect climatically relevant properties of seawater. We found the solubility of air in seawater to be by 15% lower under reduced magnetic-field (20 ?T) compared to normal field conditions (50 ?T). The magnetic-field effect on CO2 solubility is twice as large, from which we surmise that geomagnetic field variations modulate the carbon exchange between atmosphere and ocean. A 1% reduction in magnetic dipole moment may release up to ten times more CO2 from the surface ocean than is emitted by subaerial volcanism. This figure is dwarfed in front of anthropogenic CO2 emissions." (aus AGU - American Geophysical Union)

Perry, C. A. & K. J. Hsu (2000) Geophysical, archaeological, and historical evidence support a solar-output model for climate change.- PNAS, vol. 97,| no. 23: 12433-12438 (November 7, 2000). (full article!)

• Abstract:
  "Although the processes of climate change are not completely understood, an important causal candidate is variation in total solar output. Reported cycles in various climate-proxy data show a tendency to emulate a fundamental harmonic sequence of a basic solar-cycle length (11 years) multiplied by 2N (where N equals a positive or negative integer). A simple additive model for total solar-output variations was developed by superimposing a progression of fundamental harmonic cycles with slightly increasing amplitudes. The timeline of the model was calibrated to the Pleistocene/Holocene boundary at 9,000 years before present. The calibrated model was compared with geophysical, archaeological, and historical evidence of warm or cold climates during the Holocene. The evidence of periods of several centuries of cooler climates worldwide called "little ice ages," similar to the period anno Domini (A.D.) 1280-1860 and reoccurring approximately every 1,300 years, corresponds well with fluctuations in modeled solar output. A more detailed examination of the climate sensitive history of the last 1,000 years further supports the model. Extrapolation of the model into the future suggests a gradual cooling during the next few centuries with intermittent minor warmups and a return to near little-ice-age conditions within the next 500 years. This cool period then may be followed approximately 1,500 years from now by a return to altithermal conditions similar to the previous Holocene Maximum."
  (Proceedings of the by the National Academy of Sciences)
  [date of access: 04.05.07]

Priem, Harry N.A. (2004) CO2 and Climate: a Geologist's View.- Space Science Reviews, Volume 81, Numbers 1-2 / Juli 1997, pp. 173-198.

• Abstract:
  "Climate is discussed as an integral part of 'System Earth', determined by a complex interplay of numerous geological, biological and solar processes. The historical and geological record of changing climate and atmospheric CO2 pressure does not support the current popular vision that this greenhouse gas is the dominant climate controlling agent. When empirically ante post tested against past global climate changes, the 'forecasts' of the climate models mainly based on forcing by atmospheric CO2 are not borne out. On the other hand, recent studies show that solar variability rather than changing CO2 pressure is an important, probably the dominant climate forcing factor."

• Kommentar von DG Environment News Alert Service, EU Commission, 6th April 2006. - 1S.

Rasmussen, S. O., Vinther, B. M., Clausen, H. B. and K.K. Andersen (2007) Early Holocene climate oscillations recorded in three Greenland ice cores.- Quaternary Science Reviews, Volume 26, Issue 15-16, p. 1907-1914.

• Abstract:
  "A new ice core chronology for the Greenland DYE-3, GRIP, and NGRIP ice cores has been constructed, making it possible to compare the dO and accumulation signals recorded in the three cores on an almost annual scale throughout the Holocene. We here introduce the new time scale and investigate dO and accumulation anomalies that are common to the three cores in the Early Holocene (7.9 11.7 ka before present). Three time periods with significant and synchronous anomalies in the dO and accumulation signals stand out: the well-known 8.2 ka event, an event of shorter duration but of almost similar amplitude around 9.3 ka before present, and the Preboreal Oscillation during the first centuries of the Holocene. For each of these sections, we present a dO anomaly curve and a common accumulation signal that represents regional changes in the accumulation rate over the Greenland ice cap."

• Buchklappentext:"Tausend Jahre - eine Spanne, die das Leben zweier Eichen oder ein Zehntel der Nacheiszeit umfasst - sind ein Wimpernschlag der Erdgeschichte. Veränderungen in der Natur vollziehen sich in ganz anderen Zeiträumen als die Geschichte des Menschen. Josef H. Reichholf blickt aus ökologischer Sicht zurück auf das letzte Jahrtausend und untersucht die Wechselwirkung von Naturgeschichte und Geschichte, insbesondere den Klimaverlauf mit seinen ökologischen, wirtschaftlichen, politischen, sozialen und kulturellen Konsequenzen. Dabei geht es ihm stets um die Zukunft. Denn diese entwickelt sich nicht nur aus der Gegenwart, sondern sie ist Teil eines viel größeren Zeitstroms, der weit in die Vergangenheit zurückreicht. Was können wir aus der Vergangenheit bei der Bewältigung von Zukunftsproblemen lernen? Werden uns Wetter und Klima bald dafür bestrafen, dass wir zu weit gegangen sind bei unseren Eingriffen in die Natur? Josef H. Reichholf gibt realistische Einschätzungen unserer Lage und hilft uns so, die richtigen Entscheidungen für die Zukunft zu treffen."
• Rezensionsnotiz - Neue Zürcher Zeitung, 28.03.2007 (Auszug übernommen aus Perlentaucher.de)
  "Stark sei Josef H. Reichholfs Studie in dem Teil, wo sie die heutigen Natur-Apokalyptiker "ideologiekritisch" als naiv und romantisch-reaktionär entlarve. Realismus zeige der Autor auch bei seiner Analyse der eigentlichen Bedrohung heutzutage, denn nicht Umweltverschmutzung per se sei das wichtigste Problem, sondern Wasserbau und industrialisierte Landwirtschaft. ...."
  [last date of access: 12.04.07]

Santer, B. D., T M L Wigley , G A Meehl , M F Wehner , C Mears , M Schabel , F J Wentz , C Ammann , J Arblaster , T Bettge , W M Washington , K E Taylor , J S Boyle , W Brüggemann , C Doutriaux (2003) Influence of Satellite Data Uncertainties on the Detection of Externally-Forced Climate Change.- ScienceExpress 10.1126/science.1082393

Abstract:
Two independent analyses of the same satellite-based radiative emissions data yield tropospheric temperature trends that differ by 0.1 degrees C per decade over 1979 to 2001. The troposphere warms appreciably in one satellite data set, while the other data set shows little overall change. These satellite data uncertainties are important in studies seeking to identify human effects on climate. A model-predicted "fingerprint" of combined anthropogenic and natural effects is statistically detectable only in the satellite data set with a warming troposphere. Our findings show that claimed inconsistencies between model predictions and satellite tropospheric temperature data (and between the latter and surface data) may be an artifact of data uncertainties.

Sheng Hu, Feng, Darrell Kaufman, Sumiko Yoneji, David Nelson, Aldo Shemesh, Yongsong Huang, Jian Tian, Gerard Bond, Benjamin Clegg, Thomas Brown (2003) Cyclic Variation and Solar Forcing of Holocene Climate in the Alaskan Subarctic.- Science, Vol. 301. no. 5641, pp. 1890 - 1893, DOI: 10.1126/science.1088568.

Abstract:
"High-resolution analyses of lake sediment from southwestern Alaska reveal cyclic variations in climate and ecosystems during the Holocene. These variations occurred with periodicities similar to those of solar activity and appear to be coherent with time series of the cosmogenic nuclides 14C and 10Be as well as North Atlantic drift ice. Our results imply that small variations in solar irradiance induced pronounced cyclic changes in northern high-latitude environments. They also provide evidence that centennial-scale shifts in the Holocene climate were similar between the subpolar regions of the North Atlantic and North Pacific, possibly because of Sun-ocean-climate linkages."

Schiermeier, Quirin (2007) What we don't know about climate change.- News@Nature (05 Feb 2007) News.

• Summary: Uncertainty remains over feedback effects.
  Context: ...assigning a greater than 50% probability, such as the chance that human activities are affecting the intensity of hurricanes. Such care is crucial in a field that is still, in some areas, shot through with uncertainty. The IPCC has...

• Statement von Prof. Stephen Schneider im Okt. 1989 zum "drohenden" Klimawandel.

• Besprechung von Udo Leuschner.

Science News (2004): How Strongly Does The Sun Influence The Global Climate?

• ScienceDaily (Aug. 3, 2004) - "Since the middle of the last century, the Sun is in a phase of unusually high activity, as indicated by frequent occurrences of sunspots, gas eruptions, and radiation storms. Researchers at the Max Planck Institute for Solar System Research (MPS) in Katlenburg-Lindau (Germany) and at the University of Oulu (Finland) have come to this conclusion after they have succeeded in reconstructing the solar activity based on the sunspot frequency since 850 AD. To this end, they have combined historical sunspot records with measurements of the frequency of radioactive isotopes in ice cores from Greenland and the Antarctic. ..."

Solanki, S.K., N.A. Krivova & L.E. Vieira (2009) Solar magnetic field and irradiance: How unusual is the current minimum?

• AGU Fall Meeting, 14 - 18 Dec. 2009, San Francisco, USA, Lecture U34A: "Consequences of an unusually long and deep solar minimum I" [date of access: 22.02.2010]

Solanki, S. K., I. G. Usoskin, B. Kromer, M. Schüssler & J. Beer (2004) Unusual activity of the Sun during recent decades compared to the previous 11,000 years.- Nature, 28 October 2004.

• Abstract: "Direct observations of sunspot numbers are available for the past four centuries, but longer time series are required, for example, for the identification of a possible solar influence on climate and for testing models of the solar dynamo. Here we report a reconstruction of the sunspot number covering the past 11,400 years, based on dendrochronologically dated radiocarbon concentrations. We combine physics-based models for each of the processes connecting the radiocarbon concentration with sunspot number. According to our reconstruction, the level of solar activity during the past 70 years is exceptional, and the previous period of equally high activity occurred more than 8,000 years ago. We find that during the past 11,400 years the Sun spent only of the order of 10% of the time at a similarly high level of magnetic activity and almost all of the earlier high-activity periods were shorter than the present episode. Although the rarity of the current episode of high average sunspot numbers may indicate that the Sun has contributed to the unusual climate change during the twentieth century, we point out that solar variability is unlikely to have been the dominant cause of the strong warming during the past three decades."
• Vgl. Grafik 1 (11.400 Jahre) | Grafik 2 (1.075 Jahre)

• Abstract: "The magnitude of the Sun’s influence on climate has been a subject of intense debate. Estimates of this magnitude are generally based on assumptions regarding the forcing due to solar irradiance variations and climate modeling. This approach suffers from uncertainties that are difficult to estimate. Such uncertainties are introduced because the employed models may not include important but complex processes or mechanisms or may treat these in too simplified a manner. Here we take a more empirical approach. We employ time series of the most relevant solar quantities, the total and UV irradiance between 1856 and 1999 and the cosmic rays flux between 1868 and 1999. The time series are constructed using direct measurements wherever possible and reconstructions based on models and proxies at earlier times. These time series are compared with the climate record for the period 1856 to 1970. The solar records are scaled such that statistically the solar contribution to climate is as large as possible in this period. Under this assumption we repeat the comparison but now including the period 1970–1999. This comparison shows without requiring any recourse to modeling that since roughly 1970 the solar influence on climate (through the channels considered here) cannot have been dominant. In particular, the Sun cannot have contributed more than 30% to the steep temperature increase that has taken place since then, irrespective of which of the three considered channels is the dominant one determining Sun-climate interactions: tropospheric heating caused by changes in total solar irradiance, stratospheric chemistry influenced by changes in the solar UV spectrum, or cloud coverage affected by the cosmic ray flux."
  
  
• Diese Aussagen sind sicher sehr ernst zu nehmen. Gleichwohl ist die Diskussion damit noch lange nicht abgeschlossen. Man darf auf weitere Forschungsergebnisse sehr gespannt sein.

• "Seit Jahren wird von verschiedener Seite hartnäckig immer wieder postuliert, die gegenwärtige globale Erwärmung sei primär durch die Sonne verursacht. Dabei werden jedoch entsprechende Hinweise sehr selektiv herausgesucht und Untersuchungen, die dies widerlegen, unbeachtet gelassen."
  
  "Auch wenn man die extreme Annahme trifft, dass die Klimaschwankungen vor 1970 zu 100% durch die Sonne verursacht worden sind, so könnte der Sonneneinfluss aufgrund der bisher vorgeschlagenen Mechanismen höchstens etwa 30% der Erwärmung in den letzten drei Jahrzehnten erklären [S.K. Solanki and N.A. Krivova, 2003]. Dieser Temperaturanstieg kann auch in Klimamodellen nur mit Berücksichtigung der Zunahme der Treibhausgase simuliert werden."
  [last date of access: 04.05.07]
  
  Diese Aussagen sind insofern interessant, als an anderer Stelle die Temperaturerhöhung seit der "Kleinen Eiszeit" nahezu ausschliesslich auf die Zunahme der Treibhausgase zurückgeführt wird (wenn auch mit recht dubiosen Rechnungen, vgl. z.B. Umweltbundesamt, Zitat des UBA auch hier, oder Rahmstorf).
  
  
• Weitere Publikationen von und mit S. K. Solanki (Max-Plank-Institut für Sonnensystemforschung, Katlenburg-Lindau, MPG)

Soon, W. and S. Baliunas (2003) Proxy climatic and environmental changes of the past 1000 years. Climate Research 23: 89-110.

• Abstract:
  We review the 1000-year climatic and environmental history of the Earth contained in various proxy records. As indicators, the proxies duly represent local climate. Questions on the validity of locality paradigm will become sharper as climatic changes on timescales of 50-100 years or longer are being pursued. This is because the thermal and dynamical constraints imposed by local geography will become increasingly important as the air-sea-land interaction timescale increases. Because the nature of the proxy climate indicators are so different, the results cannot be combined or compared into a hemispheric or global quantitative composite. However, considered as an ensemble of individual expert opinions, the assemblage of local representations of climate establishes both the Little Ice Age and Medieval Warm Period as climatic anomalies with world-wide imprints, extending earlier results by Bryson et al. (1963), Lamb (1965), and numerous intervening research efforts. Furthermore, the individual proxies can be used to address the question of whether the 20th century is the warmest of the 2nd millennium locally. Across the world, many records reveal that the 20th century is probably not the warmest nor an uniquely extreme climatic period of the last millennium, although it is clear that human activity had impacted many microscopic realms of the climate and environment.

Spektrum der Wissenschaft (Deutsche Ausgabe des Scientific American), April 2005, S.22-24:

"Historische Temperaturwellen - Anscheinend war das Klima in den vergangenen 2000 Jahren wechselhafter als bisher gedacht. Das ergibt sich aus der Rekonstruktion des Temperaturverlaufs mit einer neuartigen Methode, die Daten von Baumringen und Sedimenten kombiniert" von Sven Titz.

" ... das Ausmass der Temperaturschwankungen im vergangenen Jahrtausend [ist] für die momentane Klimadiskussion letztlich nicht entscheidend. Das Herzstück der Szenarien für das treibhausgeplagte 21. Jahrhundert bleiben die physikalisch fundierten Computermodelle sowie die Temperaturaufzeichnungen der letzten 150 Jahre - und die lassen an Deutlichkeit nichts zu wünschen übrig." Vor allem in den letzten 15 Jahren. Doch ist überhaupt nicht entschieden, ob die gemessenen Werte (per Thermometer) nicht auch schon während des Wärme-Optimums um etwa 1100 erreicht wurden.

Spektrum der Wissenschaft (Deutsche Ausgabe des Scientific American), März 2005, S.42-49: "Das sprunghafte Klima" von Richard B. Alley.

"Eine weiter andauernde globale Erwärmung könnte plötzlich in eine neue Kaltzeit umschlagen. Solche unerwarteten Klimaumschwünge hat es in der Erdgeschichte schon mehrfach gegeben - manchmal innerhalb weniger Jahre. (...) -     'Temperatur fährt Achterbahn'   (...) Andererseits fand die Hälfte der Erwärmung seit dem Höhepunkt der letzten Eiszeit vor etwa 11.500 Jahren - ein Temperaturumschwung um mehr als 10 Grad Celsius - in nur einem Jahrzehnt statt. (...) Bisher gibt es keine glaubwürdige Vorhersage eines plötzlichen Klimawandels, und es ist auch in naher Zukunft keine zu erwarten (...) Derzeit sieht es so aus, als ob die Menschheit nicht aufhört, das Boot [metaphorisch für globales Klima] zu schaukeln und dabei gewisse Klimafaktoren näher an die Grenzen zu schieben, an denen das System kippt."

Storch, H. von, E. Zorita & F. González-Rouco (2008) Relationship between global mean sea-level and global
mean temperature in a climate simulation of the past millennium.- Ocean Dynamics (2008) 58:227–236 [last date of access: 29.12.2019]

• Keywords: Global sea-level · Temperature · Last millennium · Climate simulation · Climate change

• Einige Infos zu Prof. em. Hans von Storch
• Publications in refereed journals and books by Hans von Storch - [last date of access: 15.04.2019]

• Abstract:
  "During the last solar cycle Earth's cloud cover underwent a modulation in phase with
  the cosmic ray flux. Assuming that there is a causal relationship between the two, it is expected and
  found that Earth's temperature follows more closely decade variations in cosmic ray flux than other
  solar activity parameters. If the relationship is real the state of the Heliosphere affects Earth's climate."
  Full article [2.9MB, 12S.]

• Thejll und Lassen (auch nicht Friis-Christensen) revidieren hier nicht die Aussagen von Friis-Christiansen & Lassen (1991), wie von Rahmstorf ( Flotte Kurven - Dünne Daten, ca. 2002) behauptet, sondern ergänzen ihre Angaben lediglich ab etwa Mitte der 80er Jahre.

Tietsche, S., D. Notz, J. H. Jungclaus, and J. Marotzke (2011) Recovery mechanisms of Arctic summer sea ice, Geophys. Res. Lett., 38, L02707, doi:10.1029/2010GL045698.

• Abstract:
  "We examine the recovery of Arctic sea ice from prescribed ice-free summer conditions in simulations of 21st century climate in an atmosphere–ocean general circulation model. We find that ice extent recovers typically within two years. The excess oceanic heat that had built up during the ice-free summer is rapidly returned to the atmosphere during the following autumn and winter, and then leaves the Arctic partly through increased longwave emission at the top of the atmosphere and partly through reduced atmospheric heat advection from lower latitudes. Oceanic heat transport does not contribute significantly to the loss of the excess heat. Our results suggest that anomalous loss of Arctic sea ice during a single summer is reversible, as the ice–albedo feedback is alleviated by large-scale recovery mechanisms. Hence, hysteretic threshold behavior (or a “tipping point”) is unlikely to occur during the decline of Arctic summer sea-ice cover in the 21st century."

Toggweiler, J.R. & J. Russell (2008) Ocean circulation in a warming climate.- Nature 451, 286-288 (17 January 2008)

• Remarks:
  "Climate models predict that the ocean's circulation will weaken in response to global warming, but the warming at the end of the last ice age suggests a different outcome. (....) There is an old truism in climate circles that the cold climate at the Last Glacial Maximum (LGM), which occurred 21,000 years ago, had stronger winds. This idea fits with the common observation that it is windier in the winter than in the summer because there is greater thermal contrast within the atmosphere in the winter hemisphere. Temperature reconstructions from the LGM show that Equator-to-pole gradients in sea surface temperature were indeed larger - that is, the polar oceans were colder than the tropical ocean at the LGM in comparison with the temperature differences today. ..."

• Abstract:
  "Changes in solar activity are regularly forwarded as an hypothesis to explain the observed global warming over the last century. The support of such claims is largely statistical, as knowledge of the physical relationships is limited. The statistical evidence is revisited. Changing solar activity is a statistically plausible hypothesis for the observed warming, if short-term natural variability is the only alternative explanation. Compared to the enhanced greenhouse effect, the solar hypothesis looses a substantial part of its plausibility. Reversely, the size and significance of the estimated impact of the enhanced greenhouse effect on the global mean temperature is hardly affected by solar activity."
  Full article [7 S.]

University of Haifa (2010, Jan. 26) The sea’s ups and downs.- Publ. by the University of Haifa and Science Daily (2010, Febr. 01) Sea Level in Israel Has Been Rising and Falling Over the Last 2,500 Years.

• Excerpt:
  "The [Mediterranean] sea level in Israel has been rising and falling over the past 2,500 years, with a one-meter difference between the highest and lowest levels, most of the time below the present-day level. This has been shown in a new study supervised by Dr. Dorit Sivan, Head of the Department of Maritime Civilizations at the University of Haifa." (...)

  "Seeing as Israel is not close to former ice caps and the tectonic activity along the Mediterranean coast is negligible over these periods, it can be concluded that drastic changes in Israel's sea levels are mainly related to changes in the volume of water." (...)

  “Over the past century, we have witnessed the sea level in Israel fluctuating with almost 19 centimeters between the highest and lowest levels. Over the past 50 years Israel’s mean sea level rise is 5.5 centimeters, but there have also been periods when it rose by 10 centimeters over 10 years. That said, even acute ups and downs over short periods do not testify to long-term trends. An observation of the sea levels over hundreds and thousands of years shows that what seems a phenomenon today is as a matter of fact “nothing new under the sun”, Dr. Sivan concludes."

Usoskin, Ilya G. , S. K. Solanki, M. Schüssler, K. Mursula, K. Alanko (2003) Millenium Scale Sunspot Reconstruction: Evidence For an Unusually Active Sun Since the 1940’s.- Phys.Rev.Lett. 91 (2003) 211101 [04 S.]

• "The extension of the sunspot number series backward in time is of considerable interest for dynamo theory, solar, stellar, and climate research. We have used records of the Be-10 concentration in polar ice to reconstruct the average sunspot activity level for the period between the year 850 to the pr esent. Our method uses physical models for processes connecting the Be-10 concentration with the sunspot number. The reconstruction shows reliably that the period of high solar activity during the last 60 years is unique throughout the past 1150 years. This nearly triples the time interval for which such a statement could be made previously."
  
  Source:
  http://arxiv.org/abs/astro-ph/0310823v1 [date of access: 27.04.07]
  Längere Zusammenfassung (deutsch) in:
  innovationsreport.de [date of access: 18.01.07]
  d.h. die Sonne ist seit 1940 so aktiv wie seit 1.150 Jahren nicht mehr (Studie des Max-Planck-Instituts für Aeronomie zur Sonnenfleckenaktivität)

Vahrenholt, F. & S. Lüning (2012) Die kalte Sonne - Warum die Klimakatastrophe nicht stattfindet.- Hoffmann und Campe (445 S.).

• Vorstellung des Verlags:
  " Der Weltklimarat irrt. Die Klimadebatte muss neu geführt werden.Entgegen den Prognosen ist die Erderwärmung seit zehn Jahren zum Stillstand gekommen. Neueste Erkenntnisse belegen, dass dies maßgeblich durch Ozeanzyklen und durch die Sonne verursacht ist, die in eine strahlungsarme Phase getreten ist. In großer Anschaulichkeit zeigen zwei Experten die weitreichenden Konsequenzen für unser Klima auf. Der Weltklimarat ist sich sicher: Die Klimaerwärmung ist vom Menschen verschuldet. Doch sind die berüchtigten Treibhausgase tatsächlich vornehmlich für unser Klima verantwortlich? Und warum wird es nicht mehr wärmer? Vahrenholt und Lüning haben sich im Laufe ihrer Untersuchungen intensiv mit den verschiedenen Klimamodellen beschäftigt. Sie kommen zu der Auffassung, dass die Erderwärmung der letzten 150 Jahre Teil eines natürlichen Zyklus ist, der überwiegend von der Sonne geprägt wird. Die nächsten Jahrzehnte werden eher zu einer leichten Erdabkühlung als zu einer weiteren Erwärmung führen. Das bietet Zeit, erneuerbare Energieträger zielgerichtet auszubauen und diese Umstellung in ökonomisch vernünftiger Weise und nachhaltig zu gestalten."

van Asselt M.B.A. & Rotmans J. (2002) Uncertainty in Integrated Assessment Modelling.- Climatic Change, Volume 54, Numbers 1-2, July 2002 , pp. 75-105.

• Abstract:
  
  "Integrated Assessment (IA) aims to facilitate decision-making processes on complex issues. Dealing with uncertainty is principally at the core of Integrated Assessment. IA practitioners realise that. However:

  - Not all uncertainties can be adequately addressed with existing methods and tools. This especially holds for uncertainty in model structure and uncertainty due to behavioural and societal variability, value diversity, technological surprise, ignorance and indeterminacy.

  - Uncertainty is usually treated as a marginal issue, as an additional physical variable, as a mathematical artifact. The current methods merely involve evaluation of the impacts of `certain uncertainties', i.e. uncertainties for which estimates or probability distributions are available.

  - Current methods give no indication of the magnitude and sources of the various underlying uncertainties and the aggregated uncertainty measures are difficult to understand to decision-makers and other audiences.

  Within the International Centre for Integrative Studies, Maastricht University (the Netherlands), the research project `Perspectives on uncertainty and risk' aims to develop alternative, complementary approaches to uncertainty management in Integrated Assessment. The current paper summarises the theoretical analysis of the concept of uncertainty, and it proposes a typology of sources of uncertainty. This paper further discusses insights and experiences with pluralistic uncertainty management in the context of Integrated Assessment modelling in order to assess the strengths and weaknesses of such an approach. Although systematic fundamental uncertainty research is still needed in the context of Integrated Assessment, this paper argues that significant profit in quality terms can be gained by using the available methods, including the pluralistic approach, more consciously and systematically."

Veizer, Jan (2005) Celestial Climate Driver: A Perspective from Four Billion Years of the Carbon Cycle.- Geoscience Canada, Vol. 32, No. 1, 13-28 (March 2005).
Sehr zu empfehlen!!

• Full Article - auch als [16 S.]
• Abstract:
  "The standard explanation for vagaries of our climate, championed by the IPCC (Intergovernmental Panel on Climate Change), is that greenhouse gases, particularly carbon dioxide, are its principal driver. Recently, an alternative model that the sun is the principal driver was revived by a host of empirical observations. Neither atmospheric carbon dioxide nor solar variability can alone explain the magnitude of the observed temperature increase over the last century of about 0.6[degrees]C. Therefore, an amplifier is required. In the general climate models (GCM), the bulk of the calculated temperature increase is attributed to "positive water vapour feedback". In the sun-driven alternative, it may be the cosmic ray flux (CRF), energetic particles that hit the atmosphere, potentially generating cloud condensation nuclei (CCN). Clouds then cool, act as a mirror and reflect the solar energy back into space. The intensity of CRF reaching the earth depends on the intensity of the solar (and terrestrial) magnetic field that acts as a shield against cosmic rays, and it is this shield that is, in mm, modulated by solar activity."
  
  
• Acknowledgement:
  "In my four decades of research into the evolution of the Earth, always with strong environmental connotations, I was almost exclusively financed by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Deutsche Forschungsgemeinschaft (DFG). In the last decade, particularly relevant to this article, the research was supported by two major sources, the top research award of the DFG (Leibniz Prize endowed with 3 million DM) and the support of the Research Chair in "Earth System" financed jointly by NSERC and the Canadian Institute for Advanced Research (CIAR). The donors to CIAR include Noranda and Dr. G.G. Hatch, with the sponsorship based on an arms' length relationship via CIAR and NSERC.

  Personally, this last decade has been a trying period because of the years of internal struggle between what I wanted to believe and where the empirical record and its logic were leading me. This article is clearly not a comprehensive review of the alternatives, partly because of space limitations, but also because the case for the alternatives was eloquently argued elsewhere (e.g., IPCC, 2001). It is rather a plea for some reflection in our clamour for over-simplified beliefs and solutions in the face of the climate conundrum. Due to space considerations, the article also does not explore the potential role that the lethal CRF may have played in the evolution of life, as a cause of extinctions and/or mutations. And above all, this article is not a discussion of Kyoto, a treaty with social, economic and political aims, but a scientific treatise of the past climate record. Time will rule on its validity, but in the meantime I ask that the discussion of its merits/demerits be confined to scientific ways and means.
  
  As a final point, I am indebted to several experts worldwide, covering the whole gamut of fields from astrophysics to biology and modeling, who agreed to read the manuscript in order to make sure that its statements are scientifically defensible. The journal reviewers, Brendan Murphy and Alan Hildebrand, helped to set the tone of the presentation."

Vieira, L. E. A. & S. K. Solanki (2010) Evolution of the solar magnetic flux on time scales of years to millenia.- A & A, Volume 509, January 2010.

• Abstract
  "Aims.
  We improve the description of the evolution of the Sun's open and total magnetic flux on time scales of years to millenia.
  Methods.
  In the model employed here the evolution of the solar total and open magnetic flux is computed from the flux emerging at the solar surface in the form of bipolar magnetic features, which is related to the sunspot number cycle parameters and can be estimated from historical records. Compared to earlier versions of the model in addition to the long-lived open flux, now also a more rapidly decaying component of the open flux is considered. The model parameters are constrained by comparing its output with observations of the total surface magnetic flux and with a reconstruction of the open magnetic flux based on the geomagnetic indexes. A method to compute the Sun's total magnetic flux and the sunspot number during the Holocene, starting from the open flux obtained from cosmogenic isotopes records, is also presented.
  Results.
  By considering separately a rapidly evolving and a slowly evolving component of the open flux the model reproduces the Sun's open flux, as reconstructed based on the aa-index, much better and a reasonable description of the radial component of interplanetary magnetic field data is obtained. The greatest improvement is in the reproduction of the cyclic variation of the open flux, including the amplitudes of individual cycles. Furthermore, we found that approximately 25% of the modeled open flux values since the end of the Maunder minimum are lower than the averaged value over 2008, i.e. during the current low minimum. The same proportion is observed in reconstructions of the open flux during the Holocene based on cosmogenic isotopes, which suggests that the present solar minimum conditions are below average, but not exceptional in terms of the heliospheric magnetic flux."

• Abstract:
  "The inverse relation between atmospheric carbon dioxide concentration and stomatal frequency in tree leaves provides an accurate method for detecting and quantifying century-scale carbon dioxide fluctuations. Stomatal frequency signatures of fossil birch leaves reflect an abrupt carbon dioxide increase at the beginning of the Holocene. A succeeding carbon dioxide decline matches the Preboreal Oscillation, a 150-year cooling pulse that occurred about 300 years after the onset of the Holocene.
  In contrast to conventional ice core estimates of 270 to 280 parts per million by volume (ppmv), the stomatal frequency signal suggests that early Holocene carbon dioxide concentrations were well above 300 ppmv."
  Full article

Whitehouse, David (2007) The truth is, we can't ignore the sun.- Publ. in Telegraph Online.

Dr David Whitehouse is an astronomer, former BBC science correspondent, and the author of The Sun: A Biography (John Wiley & Sons)

• Abstract:
  "Recent indirect data and direct measurements from ice cores point towards a ‘pre-industrial’ CO2 level of around 260–270 ppmv, considerably below the commonly assumed value of 290 ppmv. Early measurements from the southern hemisphere tend to favour the lower value."

Willis, J. K. (2010) Can in situ floats and satellite altimeters detect long-term changes in Atlantic Ocean overturning?, Geophys. Res. Lett., 37, L06602, doi:10.1029/2010GL042372.

• Abstract:
  "Global warming has been predicted to slow the Atlantic Meridional Overturning Circulation (AMOC), resulting in significant regional climate impacts across the North Atlantic and beyond. Here, satellite observations of sea surface height (SSH) along with temperature, salinity and velocity from profiling floats are used to estimate changes in the northward-flowing, upper limb of the AMOC at latitudes around 41°N. The 2004 through 2006 mean overturning is found to be 15.5 ± 2.4 Sv (106 m3/s) with somewhat smaller seasonal and interannual variability than at lower latitudes. [folgende Hervorhebungen durch den Autor]

  • There is no significant trend in overturning strength between 2002 and 2009. Altimeter data, however, suggest an increase of 2.6 Sv since 1993, consistent with North Atlantic warming during this same period.
  • Despite significant seasonal to interannual fluctuations, these observations demonstrate that substantial slowing of the AMOC did not occur during the past 7 years and is unlikely to have occurred in the past 2 decades."

• Abstract: [4 S.]
  "A series of satellite total solar irradiance (TSI) observations can be combined in a precise solar magnetic cycle length composite TSI database by determining the relationship between two non-overlapping components: ACRIM1 and ACRIM2. [Willson and Hudson, 1991; Willson, 1994] An ACRIM composite TSI time series using the Nimbus7/ERB results [Hoyt et al., 1992] to relate ACRIM1 and ACRIM2 demonstrates a secular upward trend of 0.05 percent-per-decade between consecutive solar activity minima. [Willson, 1997] A PMOD TSI composite using ERBS [Lee et al., 1995] comparisons to relate ACRIM1 and ACRIM2 [Fröhlich and Lean, 1998] differs from the ACRIM composite in two significant respects: a negligible trend between solar minima and lower TSI at solar maxima.
  
  Our findings indicate the lower PMOD trend and lower PMOD TSI at the maxima of solar cycles 22 and 23 are artifacts of ERBS degradation. Lower PMOD TSI during the maximum of cycle 21 results from modifications of Nimbus7/ERB and ACRIM1 published results that produces better agreement with a TSI/solar proxy model [Foukal and Lean, 1988; Lean et al., 1995; Fröhlich and Lean, 1998]."
  
  Vgl. dazu: Fröhlich (2006) und/oder "Solar Constant - Construction of a Composite Total Solar Irradiance (TSI) Time Series from 1978 to present"

Wunsch, Carl (2004)Gulf Stream safe if wind blows and Earth turns.- Correspondence in Nature 428, 601 (8 April 2004)

• Remarks:
  "Your News story "Gulf Stream probed for early warnings of system failure" (Nature 427, 769; 200410.1038/427769a [2004, by Quirin Schiermeier]) discusses what the climate in the south of England would be like "without the Gulf Stream". Sadly, this phrase has been seen far too often, usually in newspapers concerned with the unlikely possibility of a new ice age in Britain triggered by the loss of the Gulf Stream.
  • European readers should be reassured that the Gulf Stream's existence is a consequence of the large-scale wind system over the North Atlantic Ocean, and of the nature of fluid motion on a rotating planet. The only way to produce an ocean circulation without a Gulf Stream is either to turn off the wind system, or to stop the Earth's rotation, or both.

  Real questions exist about conceivable changes in the ocean circulation and its climate consequences. However, such discussions are not helped by hyperbole and alarmism. The occurrence of a climate state without the Gulf Stream any time soon — within tens of millions of years — has a probability of little more than zero."

  Siehe weitere Publikationen von und mit Prof. Carl Wunsch (u.a.MIT)