While the premature flowering of cypresses leads to a red alert in seven departments for very high risks of pollen allergy, Fanny Agostini is interested in is called palynology, a very specific branch of climatology which makes it possible to trace the evolution of the climate very precisely thanks to pollens.
Red alert in seven departments for very high risks of pollen allergy. The abnormal sweetness has indeed activated the flowering of the cypresses. An exceptional situation at this time of year which brings Fanny Agostini to tell us about pollens but from another angle. They would be able to take us back in time.
Pollens are encyclopedias, first class archives. They can tell us a lot about climatic fluctuations and make us go back in time over thousands of years. A discipline which has a name, the study of pollens is called palynology, it is a very specific branch of climatology which makes it possible to trace the evolution of the climate in a very precise way.
How can you find pollen that old?
You don't come across it by chance, you have to go snooping around in places deprived of oxygen where the fossilization of pollen could be done, like in lake sediments or even peat bogs where the conservation of plant debris is ultra efficient. It is here that scientists make cores, sort of vertical sections which allow establishing a climatic chronology thanks to the pollen spores which have not aged. Each pollen spore will correspond to a type of vegetation which itself will coincide with a specific climate. Thus, starting from the principle that plants are distributed according to climates, you can deduce that the concentration of pollen of spruce and larch reveals a cold climate while the presence of pollens of beech, oak, maple and linden will mean that the climate was more temperate at a given time.
Which means that the pollen that is accumulating today is a marker of climate change?
Yes, at the rate with which our vegetation changes, the palynologists of the future will probably notice an edifying break in the 21st century of our era. A brief story between pollen and humanity that will tell the brutal climate change that occurred between the 20 and the 21st century and our allergy to take strong actions to reverse the trend.