Is the present day the warmest period in the last millennia? Evidences from glaciers and ice patches in the Pyrenees
Continental-scale surface temperature reconstructions show, with high confidence, multidecadal periods during the Medieval Climate Anomaly (year 950 to 1250) that were in some regions as warm as in the late 20th century. These regional warm periods did not occur as coherently across regions as the warming in the late 20th century but it has been used to hypothesize that it forced the Pyrenean glaciers to dissapear.
Thus, the current ice we observe in relict glaciers was formed duing the Little Ice Age (1600-1850). In this proyect, throughout the extraction of ice cores in the Monte Perdido glacier we are going to constrain the age of the glacial ice in the Pyrenees to confirm (or not) that the last 50 years warming exceeds natural variability of last millennia. If not, we will question the “unprecedent” retreat of Pyrenean glaciers and demonstrate that other recent warm periods were warmer (or drier) than late twentieth century.
Besides dating the glacial ice, the study of ice cores will make available a new record of past climate variability to better understand the climate system, its natural variability in the past and the impacts of abrupt climate changes in the high mountain environment. We will carry out a multy-proxy study in the ice, including the isotopic analyses (d18O) as potential paleothermometer, the interpretation of pollen content in terms of vegetation cover, the quantification of chemical content (eg. eolian dust) and the identification of microorganism associations (bacteria). The interpretation of all these proxies as a whole is going to provide a paleoenvironmental reconstruction in the Pyrenean high mountain region where other archives with paleoclimate information are very scarce.