Julien Riel-Salvatore has been following the fungus problems at Lascaux. His earlier post discusses a December NY Times article on the problem. That article is a really good one, it explains why this fungus problem is different from the white fusarium fungus that preservationists battled in the cave in 2001.
Whatever the reason for the problems at Lascaux, the white mold outbreak in 2001 led the government to close it to all nonessential visitors.
It was so serious that, to stop the invasion, the floor was covered with quicklime and scientists began treating the problem chemically, said Marc Gauthier, president of the International Scientific Committee for Lascaux, which was created as a result of the crisis.
The new problem at Lascaux, however, does not appear to be linked to the fusarium fungus. Described by experts as black stains, the blemishes are in fact both gray and black. "They vary from a few millimeters to 4 centimeters," said Mr. Geneste, noting that most are found in the passages where the rocks are most porous and paintings had faded the most long before modern man entered. While only a few stains have affected the paintings, they have now been found in some 70 different spots.
Now, Julien links to a more recent story from the CBC, which describes the political pettifog between the International Scientific Committee and the French government:
[The team of specialists] put pressure on the French government by alerting UNESCO, which classifies the caverns as a World Heritage Site, about the conditions.
Laurence Leaute-Beasley, president of the International Committee for the Preservation of Lascaux, called for the management of the caves to be taken out of the hands of the French government, saying someone who understands the science involved should take over.
The French government, not wanting such an an important site to be seen as neglected, has decided to accept the committee's advice and act now against the fungus.
So they were threatening to bring the UN into France to fight an invasive subterranean fungus. Don't tell the "black helicopter" believers!
The experts disagreed on the cause of the problem. Some say global warming is to blame, others that human activity in the caves is exacerbating the problems.
Global warming is not to blame. It's not a totally silly idea -- the Times article discusses an increase in the average soil temperature around several caves, and Lascaux is a relatively shallow one that might be influenced by increasing soil temperatures. But the climate around these caves has fluctuated a whole lot more during the last 20,000 years than in the last 20. The important recent changes have been caused by people -- walking into the cave, lighting the cave, ventilating the cave.
But now that the changes have been initiated, they can't be solved by people just leaving the cave alone. It seems like such a curious contrast -- archaeologists know they must destroy the sites to learn from them; art historians must preserve their objects to learn from them. Lascaux is both site and object, and has faced both pressures.