By Dr. Sebastian Lüning and Prof. Fritz Vahrenholt
(Text translated by P Gosselin)
The hockey stick controversy over a temperature reconstruction of the past 2000 years represents an important stage in the climate debate. At around the turn of the millennium, the authors of the “hockey stick chart” suggested that the pre-industrial climate was monotonous and uneventful. The Medieval Warm Period and Little Ice Age described in many parts of the world climatically must have been very similar. But that’s hard to understand if you look at the wide variety of case studies.
Cover-up absurdity, then forced to correct
Later, the authors improved and presented a corrected version, which again showed stronger climatic fluctuations. Quite a science story. You can read about it here.
In addition to this scientific rush job, the debate about the hockey stick also showed that climate data really must be made publicly available. This is all the more important if the science is used for far-reaching policies. Data and results obtained thereof must be verifiable. At the time no one wanted the data to be released. Today in retrospect that was quite an absurdity — similar to smoking in a large open office.
Fortunately, the situation has since greatly improved. Many climate and paleoclimate data are available from online databases (such as Pangea or NDCD) for everyone. Many authors willingly provide their data via email. A good development.
Good deal of ideology involved?
It seems anachronistic when suddenly old cases from an earlier time appear. It is still unclear what the authors of the legendary hockey stick curve really did. Was it pure scientific belief or the secret desire to smooth the changing pre-industrial climate development by hand?
After security breaches, leaked emails in the context of the Climategate events suggest that a good deal of ideology was involved. It is no coincidence that lead author Michael Mann is among the climate activists today, and maintains good contacts with like-minded people in Germany, such as Stefan Rahmstorf.
Suspense over long overdue release of emails
After a long legal dispute, the University of Arizona will probably have to make some email communications between the hockey stick authors public. The university now declares that it will not impose any further hurdles, and so that it will soon be possible to publish the documents that have since become climate science history.
We wait with suspense. Details can be found at WUWT here.