Should climatology explain the Arctic warming since winter 1918/19?
It is the most pronounced single climatic event since the volcanic Krakatoa eruption, the sudden extreme temperature rise in the Arctic region for two decades since winter 1918/19. Suddenly the temperatures literally exploded. The extraordinary event from 1918 to 1939 is clearly demonstrated in the graph showing the ‘Arctic Annual Mean Temperature Anomalies 1880 – 2008’. Meanwhile almost a full century has passed, and what do we know about this event today? Very little! Scientific literature is quite superficial concerning all three questions: Where? When? Why? That is deplorable and hardly convincing when listing to the climate change debate and all the academic discussion on predicting future climate conditions. Climatology should be required very decisively to explain the arctic warming since 1918 comprehensively and very soon. That this is by far not an impossible undertaking is thoroughly demonstrated and discussed on this site, which is fully committed to the arctic warming event that started in winter 1918/19, which corresponds to about 40 text pages plus graphs.
Recent conclusion on the arctic warming in the 1920s/1930s:
- Natural fluctuations are a component of the climatic system (Johannessen, et al.  ) ;
- Natural variability is the most likely cause (Bengtsson, et al.);
- Sun has partly caused the warming (Daly) ;
- The 1930s warm period did not coincide with a positive phase of the NAO (North Atlantic Oscillation (Polyakov, et al.)
An even more superficial description has been given by the latest IPCC’s Summary for Policymakers in February 2007:
Average Arctic temperatures increased at almost twice the global average rate in the past 100 years. Arctic temperatures have high decadal variability, and a warm period was also observed from 1925 to 1945.
One century has passed since arctic warming started, and IPCC seems unable and unwilling to get even the most basic facts right. The following investigation tries to offer clues and explanations what actually happened in the Arctic realm at the end of the 1910s and what may have caused the arctic warming at the beginning of the last century.
What is up for discussion?
Three issues are hotly debated worldwide: Climate Change, Global Warming, and Anthropogenic Forcing. Understanding the Arctic warming in the early last Century would significantly contribute to a more fruitful discussion of each of these subjects.
The fact is that the winter temperatures made a jump of more than eight degrees Celsius at the gate of the Arctic Basin, after 1918. Nowadays, one century later, the event is still regarded as “one of the most puzzling climate anomalies of the 20 th century”.This shows that there hasn’t been any convincing progress on understanding the climatic change issue! The first to wonder about this subject was the Norwegian scientist B.J. Birkeland who stressed in his findings, back in 1930, that it could “probably be the greatest yet known on earth” (see Table of Temperatures at Annex I). Although this extreme warming event is known for many decades, the Intergovernmental Panel on Climate Change (IPCC) mentioned recently that the “average Arctic temperatures increased at almost twice the global average rate in the past 100 years”, and that this represents a very significant part of the global warming issue. That is of little help if not a straight disservice to the climate debate.
What need to be acknowledged is that the ‘hot issue’ was measured in the winter of 1918/19 on the remote Norwegian island of Spitsbergen, just 1,000 kilometres away from the North Pole. Spitsbergen experienced an increase of winter temperatures of more than 8º Celsius within only a few years. When the event started, the actual figure was particularly high (see: graph), and spread out far beyond the local region over a short period of time.
But if IPCC acknowledges the arctic warming, why do we still need to go to back to the beginning of the 20 th century to find out the reasons of the ‘Big Warming’ at Spitsbergen? Isn’t it enough to accept modern scientific theories, which point to “internal variability of the climate system”, while excluding three other possible mechanisms, namely: anthropogenic effects, increased solar irradiation, and reduced volcanic activity?Certainly not! The warming at Spitsbergen is one of the most outstanding climatic events since the volcanic eruption of Krakatoa, in 1883. The dramatic warming at Spitsbergen may hold key aspects for the understanding how climate ticks. The following section wants to approach the matter from different angles, but on a straight line of thoughts, namely:
- WHERE: the warming was caused and sustained by the northern part of the Nordic Sea in the sea area of West Spitsbergen the pass way of the Spitsbergen Current.
- WHEN: The date of the commencement of warming can be established with high precision of few months, and which was defiantly in place by January 1919.
- WHY: the sudden and significant temperature deviation around the winter of 1918/19 was with considerable probability caused, at least partly, by a devastating naval war which took place around the Great Britain, between 1914 and 1918.
Current conclusions, as outlined above, will be challenged at least on the ground that:
- The “Big Warming” event from Spitsbergen proves that the climate change was not determined by the atmosphere; but first of all, if not alone by the sea.
If climate were defined as ‘the continuation of the oceans by other means’ , the arctic warming would –with high certainty- have been fully understood and explained since long, and thus could have provided a big service to the general climatic change debate.
- Ola M. Johannessen, Lennart Bengtsson, Martin W. Miles, Svetlana I. Kuzmina, Vladimir A. Semenov, Genrikh V. Alekseev, Andrei P. Nagurnyi, Victor F. Zakharov, Leonid Bobylev, Lasse H. Pettersson, Klaus Hasselmann and Howard P. Cattle; Arctic climate change – Observed and modeled temperature and sea ice variability; Nansen Environmental and Remote Sensing Center, Report No. 218, Bergen 2002; Tellus 56A (2004), p. 328 –341, Corr. 559-560. ;
- Lennart Bengtsson, Vladimir A. Semenov, Ola M. Johannessen, The Early Twentieth-Century Warming in the Arctic—A Possible Mechanism, Journal of Climate, October 2004, page 4045-4057;
- I.V.Polyakov, et.al.; Variability of the Intermediate Atlantic Water of the Arctic Ocean over the last 100 Years, Journal of Climate, Vol.17, No.23, 2004.
- IPCC – Climate Change 2007, WG I, The Physical Science Basis; Summary for Policymakers; released in Paris on February, 2nd, 2007 , http://ipcc-wg1.ucar.edu/wg1/docs/WG1AR4_SPM_PlenaryApproved.pdf
- see: Bengtsson et al.; Op. cit (FN 3)
- B.J. Birkeland , Temperaturvariationen auf Spitzbergen, Meteorologische Zeitschrift, June 1930, p. 234-236.
- IPCC; Op. cit. (Fn 6).
- See: Bengtsson et.al; Op. cit. (FN 3).
- A number of papers by Arnd Bernaerts since 1992 suggest to use this term; see: www.oceanclimate.de.