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Im letzten Jahrzehnt hat sich die Landschaft zum Unterrichtsfach Sachunterricht bzw. «Natur, Mensch, Gesellschaft» (NMG) an den Pädagogischen Hochschulen der Deutschschweiz grundlegend verändert. Dies ist insbesondere auf die Tertiärisierung der Lehrpersonenausbildung zurückzuführen, aber auch auf die verbindliche Einführung des Lehrplan 21 in den deutschsprachigen Kantonen der Schweiz und im Fürstentum Lichtenstein und die damit einhergehende Orientierung an Kompetenzen. Ein weiterer wichtiger Einflussfaktor war das Erscheinen des Perspektivrahmens der Gesellschaft für die Didaktik des Sachunterrichts, welcher erstmals ein (länder-)übergreifendes fachliches und didaktisches Konzept des Sachunterrichtes auswies und somit einen gemeinsamen Fachdiskurs erleichterte. In dem von Breitenmoser, Mathis und Tempelmann 2021 editierten Herausgeberwerk «Natur, MensCH, GesellsCHaft (NMG) - Standortbestimmungen zu den sachunterrichtsdidaktischen Studiengängen der Schweiz» stellen sechzehn Schweizer Pädagogische Hochschulen ihre Studiengänge und Fortbildungsprogramme im Fach Sachunterricht bzw. NMG, wie auch ihre Forschungstätigkeiten in diesem Bereich vor. Die Beiträge zeigen den Wandel, die Gemeinsamkeiten und die Vielfalt der Umsetzungen deutlich. Damit wird eine einmalige Bestandesaufnahme der aktuellen Situation einer fachdidaktischen Disziplin an den Pädagogischen Hochschulen der Schweiz geboten und ganz unterschiedliche Optionen und Varianten für die Ausgestaltung der tertiären Ausbildung im Studienfach Sachunterricht/NMG aufgezeigt. Diese vielfältigen Einblicke in die unterschiedlichen Schweizer Studiengänge und Fortbildungsprogramme im Fach NMG, ermöglichen den professionellen Austausch zwischen den unterschiedlichen Hochschulen und bieten Denkanstösse für die Sachunterrichtsausbildung, auch ausserhalb der Schweiz. Im folgenden Beitrag wird die Entwicklung der sachunterrichtsdidaktischen Studiengänge der Schweiz aufgezeigt und auf zentrale Erkenntnisse aus dem Vergleich der Ausbildungskonzepte eingegangen., +repphzhbib2022A

The Sun is the main driver of Earth's climate, yet the Sun's role in forcing decadal-to-centennial climate variations has remained controversial, especially in the context of understanding contributions of natural climate forcings to continuing global warming. To properly address long-term fingerprints of solar forcing on climate, long-term, very high-resolution, globally distributed climate proxy records are necessary. In this study we compile and evaluate a near global collection of annually-resolved tree-ring-based climate proxies spanning the past two millennia. We statistically assess these records in both the time and frequency domains for solar forcing (i.e. Total Solar Irradiance; TSI) and climate variability with emphasis on centennial time scales. Analyses in the frequency domain indicate significant periodicities in the 208-year frequency band, corresponding to the DeVries cycle of solar activity. Additionally, results from Superposed Epoch Analysis (SEA) point toward a possible solar contribution in the temperature and precipitation series. However, solar-climate associations remain weak, with for example no clear linkage distinguishable in the southwestern United States drought records at centennial time scales. Other forcing factors, namely volcanic activity, appear to mask the solar signal in space and time. To investigate this hypothesis, we attempted to extract volcanic signals from the temperature proxies using a statistical modelling approach. Wavelet analysis of the volcanic contribution reveals significant periodicities near the DeVries frequency during the Little Ice Age (LIA). This remarkable and coincidental superposition of the signals makes it very difficult to separate volcanic and solar forcing during the LIA. Nevertheless, the “volcano free” temperature records show significant periodicities near the DeVries periodicity during the entire past 1500 years, further pointing to solar mechanisms and emphasising the need for solar related studies in the absence of strong multi-decadal volcanic forcing.

The European Alps are very sensitive and vulnerable to climate change. Recent improvements in Alpine glacier length records and climate reconstructions from annually laminated sediments of Alpine Lake Silvaplana give the opportunity to investigate the relationship between these two data sets of Alpine climate. Two different time frames are considered: the last 500-1000 years as well as the last 7400 years. First, we found good agreement between the two different climate archives during the past millennium: mass accumulation rates and biogenic silica concentration are largely in phase with the glacier length changes of Mer de Glace and Unterer Grindelwaldgletscher, and with the records of glacier length of Grosser Aletschgletscher and Gornergletscher. Secondly, the records are compared with temporally highly resolved data of solar activity. The Sun has had a major impact on the Alpine climate variations in the long term, i.e. several centuries to millennia. Solar activity varies with the Hallstatt periodicity of about 2000 years. Hallstatt minima are identified around 500, 2500 and 5000 a. Around these times grand solar minima (such as the Maunder Minimum) occurred in clusters coinciding with colder Alpine climate expressed by glacier advances. During the Hallstatt maxima around 0, 2000 and 4500 a, the Alpine glaciers generally retreated, indicating a warmer climate. This is supported by archaeological findings at Schnidejoch, a transalpine pass in Switzerland that was only accessible when glaciers had retreated. On shorter timescales, however, the influence of the Sun cannot be as easily detected in Alpine climate change, indicating that in addition to solar forcing, volcanic influence and internal climate variations have played an important role. Copyright # 2011 John Wiley & Sons, Ltd.

We investigate relationships between climate and tree-ring data on a global scale using the process-based Vaganov–Shashkin Lite (VSL) forward model of tree-ring width formation. The VSL model requires as inputs only latitude, monthly mean temperature, and monthly accumulated precipitation. Hence, this simple, process-based model enables ring-width simulation at any location where monthly climate records exist. In this study, we analyse the growth response of simulated tree rings to monthly climate conditions obtained from the CRU TS3.1 data set back to 1901. Our key aims are (a) to assess the VSL model performance by examining the relations between simulated and observed growth at 2287 globally distributed sites, (b) indentify optimal growth parameters found during the model calibration, and (c) to evaluate the potential of the VSL model as an observation operator for data-assimilation-based reconstructions of climate from tree-ring width. The assessment of the growth-onset threshold temperature of approximately 4–6 °C for most sites and species using a Bayesian estimation approach complements other studies on the lower temperature limits where plant growth may be sustained. Our results suggest that the VSL model skilfully simulates site level tree-ring series in response to climate forcing for a wide range of environmental conditions and species. Spatial aggregation of the tree-ring chronologies to reduce non-climatic noise at the site level yielded notable improvements in the coherence between modelled and actual growth. The resulting distinct and coherent patterns of significant relationships between the aggregated and simulated series further demonstrate the VSL model's ability to skilfully capture the climatic signal contained in tree-ring series. Finally, we propose that the VSL model can be used as an observation operator in data assimilation approaches to reconstruct past climate.