The National and Kapodistrian University of Athens is participating in the study.

A new international study, the results of which were published in the scientific journal Nature, captures the history of climate change in the Mediterranean region for the past 1.36 million years, starting with the analysis of the sediments of Europe's oldest lake. Assistant Professor Katerina Kouli from the National and Kapodistrian University of Athens is participating in the study.

According to the study "Mediterranean winter rainfall in phase with the African monsoon over the last 1.36 million years" published in the journal Nature by a team of 47 researchers from 13 countries led by Dr. Bernd Wagner of the University of Cologne, the future climate trend in the Mediterranean, due to global warming, is likely to be characterized by more extreme phenomena, with warmer and drier summers and greater instability in autumn, particularly heavy rainfall between September and December.

This is the conclusion of a study of the sedimentary record of Lake Ohrid, the oldest lake in Europe, at the border between Albania and Northern Macedonia. The lake is known for its remarkable biodiversity, as its ecosystem includes 300 endemic species of animals and plants. This unique Mediterranean ecosystem has been systematically studied during the last years by an international team of scientists. The scientific project aimed to obtain new information about the age and origin of the lake, the climate history of the northern Mediterranean region, and the reasons for the high degree of endemism and biodiversity. Fieldwork took place in 2013 and was one of the most successful lake drilling campaigns of the International Continental Scientific Drilling Program (ICDP). The drilling reached a maximum depth of 568 m into the sediments at the bottom of the lake in a water depth of 245 m.

It took five years to analyse the recovered sediment cores using many independent techniques to provide a robust understanding of past climate and environmental change. The science team have now revealed that the lake first established 1.36 million years ago and existed continuously since then.

The extensive sediment succession of Lake Ohrid has allowed the reconstruction of past climate conditions over the entire history of the lake in exquisite detail, turning out to be a unique high resolution paleoclimate archive for the Mediterranean region. The combination of the temporal changes of vegetation, as depicted in past pollen assemblages, with the sedimentological data shows that winter rainfall increased in the northern Mediterranean region during warm, interglacial periods. During these intervals, climate model simulations indicate increased cyclogenesis over the western Mediterranean particularly during autumn. The increased cyclogenesis was most likely due to warm sea-surface temperatures, which led to considerably higher rainfall in the northern Mediterranean borderlands. Similar effects could arise from recent human-driven climate warming. As climate predictions from the Intergovernmental Panel on Climate Change (IPCC) show an inconsistent picture of future climate change for this region, the new results from Lake Ohrid will help to better constraint future climate scenarios.

link:

Wagner, B. Vogel H., , Francke A., Friedrich T., Donders T., Lacey J., Leng M., Regattieri E., Sadori L., Wilke T., Zanchetta G.,Albrecht C., Bertini A., Combourieu-Nebout N., Cvetkoska A., Giaccio B., Grazhdani A., Hauffe T., Holtvoeth J., Sebastien Joannin S., Elena Jovanovska E., Janna Just J., Kouli K., Kousis I., Koutsodendris A., Krastel S., Leicher N., Zlatko Levkov Z., Katja Lindhorst K., Masi A., Melles M., Mercuri A.M., Nomade S., Nowaczyk N., Panagiotopoulos K., Peyron O., M. Reed J.M., Sagnotti L., Sinopoli G., Stelbrink B., Sulpizio R., Timmermann A., Tofilovska S., Torri P., Wagner-Cremer F., Wonik T., Zhang X. ‘Mediterranean winter rainfall in phase with African monsoon during past 1.36 million years’ Nature, DOI https://doi.org/10.1038/s41586-019-1529-0