At the academy, the conservation team with members of higher education backgrounds in the natural sciences, including chemistry, geology, microbiology and so on, is devoted to digitalization and detailed analysis in labs to draft tailored prescriptions for each earthen "patient".

"Cave conservation is about continuously solving problems," Guo says. "But the more work we do, the more problems we'll encounter.

"In the past, maybe we would rely on experience and refer to solutions that had previously been effective," he adds. "But now we realize there's no panacea. We have to make a plan for each specific scenario after a rigid evaluation."

The Mogao Caves have existed for more than 1,000 years. No matter how much effort their guards and restorers have spent, whether it is in conservation or trying to rein in the neighboring sand dunes, everyone understands a simple fact: They can only slow down the aging of caves, but they cannot stop it.

"For example, climate change is a major factor influencing the murals in the caves," Su Bomin, director of the Dunhuang Academy, says. "It needs a long-term research to better preserve the caves, over a much wider time span that goes beyond our lifetimes."