Future climate simulations show that global atmospheric temperature will rise by the end of the 21st century are very likely to exceed 1.5-2°C, or even by 2.6 to 3.1°C if the requirements of the Paris Agreement are not met. At present, the value of atmospheric CO2 surpasses 400 ppm, a level that has never been encountered since the Pliocene, when temperatures were a few degrees higher than today.
The Pliocene setting of the Earth system could be used as a model for future climate, based on the (mostly) similar topographical and hydrological settings, but efforts to understand Pliocene climate might be hampered by the reduced knowledge of geomorphological processes such as mountain uplift. During the Pliocene, the most striking feature of SE Europe was the existence of large, inter-connected lakes that were part of the Paratethys domain. As well, the Carpathian-Balkan range was continuing its recently rejuvenated uplift. The aim of our project is to investigate large-scale environmental variability between the Pliocene and the present in SE Europe in order to better understand if Pliocene interglacials could be used as a model for future warmer climates. For this, we will use oxygen stable isotopes from speleothems, mammal tooth enamel, and ostracods, in order to create a series of isotopic snapshots, supported by ostracod and pollen paleoecological and climate reconstructions. We will further use this information to test if the Pliocene environments would
be replicated in the nearest future in SE Europe.
The period between the present and the early Pliocene, although long studied from sparse environmental archives, suffers from an acute lack of chronological control and climate reconstructions.
This in turn limits our knowledge about environmental characteristics during key events over the past 5 Ma that are
crucial for the understanding of how the Earth system will behave in the next decades. To overcome this shortcomings, we need to know:
1. what the temperatures and rainfall patterns looked like over continental Europe at times such as the early Pliocene, the Mid-Pliocene warm Period, the Plio-Pleistocene transition or during
Pleistocene MIS 5e and MIS 11;
2. did most precipitation originate in the Atlantic and the Mediterranean as in the present, or were the Pliocene basins important sources, enhancing the regional hydrological cycle?
3. when did the Carpathians start to strongly influence regional climate, and would they exacerbate drought in the future by blocking even an enhanced hydrological cycle?
1. To build an oxygen stable isotope record from the present to the early Pliocene as the main tool for hydroclimate reconstructions in SE Europe using multiple environmental archives such as speleothems, ostracods, and mammal tooth enamel, from sites in the Carpathians, Dobrogea, and the Dacian Basin. We propose to build a series of isotopic snapshots that would create a more complete connection between the present and past warm periods.
2. To obtain complementary environmental information from geochemical proxies in speleothems and ostracods such as δ13C, clumped isotopes, or chemical element ratios (e.g. Mg/Ca, Sr/Ca etc.) in order to better understand oxygen variability.
3. To obtain paleoecological information from fossil assemblages of pollen, ostracods, and mammals and reconstruct temperature and hydrological conditions using pollen and ostracods. Pollen is a valuable tool in paleoenvironmental reconstructions but found little
use in speleothem science. This objective will allow us to provide not only consistent views of flora and faunal changes over such large time expanses, but will give us the opportunity to obtain quantitative temperature and rainfall data that will be used to identify the drivers behind isotopic variability on the time slices where these proxies overlap, leading to a better understanding of the whole isotope record.