Weiß der geneigte Leser, was Herr Schellnhuber publiziert, wenn er gerade einmal nicht in gewissen Zwängen steht? Vielleicht hat es mit den Mitbeteiligten an der Studie (J. F. Eichner, E. Koscielny-Bunde, A. Bunde, S. Havlin) zu tun, oder vielleicht weil er denn doch einmal wissenschaftlich AUCH gearbeitet hat, dann also heute vielleicht sogar wider besseres Wissen agiert - in einer im Internet zu findenden Studie aus dem Jahre 2002 kommt der Klimahysteriker nämlich zu bemerkenswerten Aussagen, die auch etwas über die Herangehensweise erzählen, auf denen Vorhersagen beruhen. Und da klingt noch einiges ziemlich anders. Tatsächlich seriöser. Wahrscheinlich hat er dazugelernt. Die Frage ist halt: Wobei?
In this paper, we have used a hierarchy of detrending analysis methods (DFA0–DFA3) to study long temperature records around the globe. We concentrated mainly on those areas on the globe (North America, Europe, Asia and Australia) where long records are available. The main results of the study are the following.
(i) The temperature persistence decays, after a crossover time that is typically of the order of the duration of a Grosswetterlage, by a power law, with an exponent α that has a very narrow distribution for continental stations. The mean value of the exponent is close to 0.65, in agreement with earlier calculations based on different methods [12,15–17].
(ii) On islands, the exponent shows a broader distribution, varying from 0.65 to 0.85, with an average value close to 0.8. This finding is in qualitative agreement with the results of a recent analysis of sea surface temperature records, where also long-term persistence with an average exponent close to 0.8
has been found [14]. Since the oceans cover more than 2/3 of the globe, one may expect that also the mean global temperature is characterized by long-term persistence, with an exponent close to 0.8.
(iii) In the vast majority of stations we did not see indications for a global warming of the atmosphere. Exceptions are mountain stations in the Alps [Zugspitze (D), S ̈antis (CH), and Sonnblick (A)], where urban warming can be excluded. Also, in half of the islands we studied, we found pronounced trends that most probably cannot be attributed to urban warming. Most of the continental stations where we observed significant trends are large cities where probably the fast urban growth in the last century gave rise to temperature increases.
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 (Intergovernmental Panel for Climate Change) report.
***
