(German text translated/edited by P. Gosselin)
On October 11, 2019, Spiegel Online once again shined brilliantly parroting climate alarm. The German weekly news magazine could certainly now use their former science editor, Axel Bojanowski, who looked at climate science objectively.
The topic this time was climate change in the Mediterranean region.
With reference to a study by the MedECC network (pdf here), it is claimed that the Mediterranean region is warming up faster than other regions. Oh my. But not a word about the fact that the AMO ocean cycle has been a major driver of warming here for the last three decades. We have recently shown the graph here in the blog. As AMO’s cycle starts to go down, the Mediterranean will warm less in the coming decades, and may cool. Spiegel Online will certainly suppress this headline headline.
Interestingly, the AMO gets no mention in the MedECC report, although its authors also included ocean cycle specialists (Tsimplis, Xoplaki). They probably preferred to keep their mouths shut because the lead author is Wolfgang Cramer from the PIK climate alarm hatchery.
Preindustrial climate past concealed
It is also noticeable that the new Mediterranean climate report – like many of its related reports – does not begin its reporting until 1850. The eventful climate history before that time goes unmentioned. Please recall how the history of mankind in the Mediterranean region played a very special role during the last thousands of years: Egyptians, Greeks, Romans. The associated climate history, however, is concealed by Cramer. The latter is not only active at the PIK, but also at the IPCC.
This perhaps explains the desire to leave readers in the pre-industrial climate dark.
Ocean cycles play major role
Fortunately, there’s another way. In September 2019, a research group led by Sebastian Lüning published a summary study on the Medieval Warm Period in the Mediterranean region. Most of the Mediterranean was warm at that time. However, the scientists also found regions where it became colder during the Middle Ages. The corresponding warm-cold patterns corresponded to well-known ocean cycle patterns, namely those of the NAO, the North Atlantic Oscillation.
Overall, however, the AMO also seems to have played a major role in the climatic changes of recent centuries. Here is the abstract of the study published in the journal Paleoceanography and Paleoclimatology:
The Medieval Climate Anomaly in the Mediterranean region
The Medieval Climate Anomaly (MCA) is a pre‐industrial phase of pronounced natural climate variability with a core period from 1000 to 1200 CE. The paper presents a synthesis that integrates palaeotemperature records from the Greater Mediterranean Region encompassing the past 1500 years based on multiproxy data from 79 published land and marine sites. MCA warming dominated the Western Mediterranean (Iberia, NW Africa) as well as the northern land areas of the Central and Eastern Mediterranean region. MCA cooling prevailed in the Canary Current Upwelling System, southern Levant and some sea areas of the Central and Eastern Mediterranean. Previous palaeoreconstructions suggest persistent positive Atlantic Multidecadal Oscillation (AMO+) and North Atlantic Oscillation (NAO+) conditions during the MCA, whilst the LIA was dominated by an AMO‐ and NAO‐ regime. During the past 150 years, AMO+ conditions are typically associated with warming episodes in the Mediterranean area. A similar relationship appears to have also been established during the MCA as the majority of all Mediterranean land sites experienced warm climate conditions. In contrast, the NAO typically leads to a characteristic west‐east temperature dipole pattern in the basin, as documented for the last decades. During NAO+ conditions the Western Mediterranean is generally warm (and dry), whilst large parts of the Central and Eastern Mediterranean are cold. Similar trends seem to have been developed during the MCA when the NAO+ regime led to consistent warming in the Western Mediterranean, whilst a significant number of sites with MCA cooling existed in the Central and Eastern Mediterranean.
And here’s the summary in plain language:
Mediterranean climate has been warming significantly over the past 100 years with anthropogenic climate change having become a key issue. In order to better understand modern climatic change, developments need to be placed into a longer‐term pre‐industrial context to compare with times when human CO2 emissions did not yet play a major role for climate. This paper integrates data on Medieval temperature trends from 79 published Mediterranean land and marine sites. Our synthesis shows that the Western Mediterranean (Iberia, Northwest Africa) as well as the northern land areas of the Central and Eastern Mediterranean region have experienced a warm phase 1000‐1200 CE, corresponding to the so‐called ‘Medieval Climate Anomaly’. Contemporaneous cooling occurred in other parts of the Greater Mediterranean region, namely in the southern Levant, some sea areas of the Central and Eastern Mediterranean and the Canary Current Upwelling System. The regional differences in Medieval Mediterranean temperature trends show a pattern, that partly resembles modern multidecadal temperature variability in the area. The main drivers of these patterns appear to be Atlantic ocean cycles (AMO, NAO) which episodically shift between positive and negative phases and lead to characteristic temperature effects in the region.