Doctor in prehistory and specialist in cave art, Michel Lorblanchet has dedicated his life to the study of the decorated caves of Quercy (Lot), his country.
While he published "Birth of Life - A Reading of Cave Art" with Rouergue editions, in which he delivers an interpretation of the paintings studied throughout his career, he also acts as a whistleblower to protect this universal heritage.
Faced with the development of industrial methanization, he is worried about the pollution generated in the fragile underground environments of the Quercy causses.
“The fumes from anaerobic digestion plants and the spreading of liquid digestate rapidly infiltrating the limestone are a threat to all of our natural and cultural heritage.
One day or another, a large majority of the caves will be polluted, ”he fears.
In total, more than 160 prehistoric caves are now listed in the Causses du Lot, whether they are graves, dwellings or decorated caves.
"What I am defending is heritage in all its aspects," assures the former research director at the CNRS.
The quality of the air for humans and bees on the surface.
But also the breeding, the quality of the water and the underground landscapes.
"
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The Grands Causses model
Faced with these risks, the Lot prefecture recently set up an anaerobic digestion observatory, in order to determine whether it is necessary to take measures. An initiative well received by Michel Lorblanchet, also a member of the National Scientific Committee for Reasoned Methanization (CSNM) and Alerte Méthanisation Industrielle Environnement (Amie), two associations active on the issue, which however defends itself against any agribashing. “I have lived all my life among farmers and peasants. I am for the biogas plants on the farm, not industrial. There is a formula to be found, ”he insists, as he calls on the Lot to be inspired by the Grands Causses of Aveyron-Lozère, which have been able to avoid industrial methanization. With 800,000 visitors per year,the underground environment of Lot is also a considerable economic heritage.
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“Faced with uncertainties, it might be tempting to appeal to the precautionary principle to protect archaeological knowledge buried in the ground.
Today, almost all of the national territory could in fact be considered as an archaeological reserve ”, we respond from the side of the regional directorate of cultural affairs (Drac) Occitanie, where we are closely following the issue of agricultural spraying. .
No formally identified damage
"We are not aware that damage affecting the underground archaeological heritage has been identified", adds Jean-Louis Le Guillou, engineer, in charge of monitoring these decorated caves. However, the Drac has established, on scientific grounds, a perimeter around each decorated Paleolithic cave located in the area affected by the spraying linked to the Gramat methaniser.
In 2012-2013, near the cave of Foissac (Aveyron), an industrial pigsty project "was scaled down and the threat of pollution was ruled out", recalls Sébastien du Fayet, the owner of this cave. listed as a historic monument for forty years and president of Caves and chasms of the Lot and the Dordogne Valley. He welcomes the intervention of the State and recognizes that the question is delicate. “We cannot avoid pollution upstream of the underground river. We must accept that there are activities even if, when the cave is in charge, water covers the graves. If it is loaded with products, this can modify the physicochemical conditions of storage. "