Ever wonder how climate change in the past could ever have been posible without CO2 changes? Some people, like Prof. Michael E. Mann, think it wasn’t possible and that climate was always steady back then.Mann even fabricated a hockey stick chart to precisely show that – until 1850 that is. Then man got smart, industrialized, and everything went to hell.
Well, there’s yet another temperature reconstruction out there showing once again Michael Mann was wrong, and that the climate often went to hell in the past too.
The latest proxy reconstruction comes from a German peat bog and goes back 2000 years. And in case you haven’t guessed it by now, temperatures were all over the place. So much so, that the researchers themselves even express they can’t believe their own results.
A new paper by Moschen et al appearing ain the journal Climate of the Past presents a high resolution reconstruction of local growing season temperature (GST) anomalies at Dürres Maar, Germany over the last two thousand years.
In 2007, a 5.5 m long core was recovered from the centre of Dürres Maar peat bog in the mountainous West Eifel Volcanic Field in southwestern Germany.
According to the paper’s abstract (emphasis added):
The temperature reconstruction is based on the Sphagnum δ13Ccellulose /temperature dependency observed in calibration studies. Reconstructed GST anomalies show considerable centennial and decadal scale variability. A cold and presumably also wet phase with below-average temperature is reconstructed between the 4th and 7th century AD which is in accordance with the so called European Migration Period marking the transition from the Late Roman Period to the Early Middle Ages. At High Medieval Times above-average temperatures are obvious followed by a temperature decrease.
I got a copy of the paper from a source, who wrote: “The ex-hockey team will hate it”. The paper’s Figure 6 tells quite the story. Indeed there was a lot of climate change in the past when CO2 was more or less stagnant. Look at the huge variations 1000 years ago! Obviously natural factors truly do exist. The Medieval Warm Period is shown again to be just as warm, if not warmer than today.
As reader DirkH points out in a comment, even the researchers have great difficulty coming to terms with their own results.