Ancient cave art along China's silk road is damaged in harsh rains

AILSA CHANG, HOST:

More than 1,500 years ago, followers of Buddhism started painting art inside a string of caves, threading through the desert of northwestern China. In some cases, they chiseled elaborate statues directly into the rock. These magnificent caves survived a millennium, but they face a new enemy - rain. NPR's Emily Feng brings us the story.

EMILY FENG, BYLINE: Wang Jinyu has dedicated his professional life to preserving the Mogao caves - more than 500 temples carved out of cave walls and elaborately painted, starting in the fourth century. They're in China's Zhangye and Dunhuang, oases along the ancient Silk Road.

WANG JINYU: (Through interpreter) In the summers out in Dunhuang, the sun doesn't set until 9 or 10 in the evening, and so a few of the younger researchers and I would spend the hours before dusk with the paintings in the caves. And that's how I grew to love them.

FENG: Wang was a young, promising researcher when he graduated in the 1980s, just years after China ended a decade of political turmoil called the Cultural Revolution. During that time, schools were shut down and teachers and academics beaten and imprisoned, and there wasn't much conservation expertise left in the country. So Wang was drafted to protect the Dunhuang caves and grottoes because of his chemistry background. He spent a decade repairing flaking paint and removing dust. But in the last three decades, it's rain he's most afraid of.

JINYU: (Through interpreter) This increased rain brings floods. There used to be a wide river and many grand trees in front of the Mogao caves. But a large amount of underground water now sinks into the caves as well.

FENG: And the rain then dissolves minerals in the caves to create a caustic, paint-destroying chemical process. Normally, this part of China is extremely dry. It only used to rain about an inch and a half a year, but now more rain comes down each year, even as the storms themselves become less frequent, meaning flash flooding and mudslides.

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UNIDENTIFIED PERSON: (Speaking Mandarin).

FENG: China has invested considerably on restoration work of the cave paintings, as depicted in this documentary from the research institute Dunhuang Academy. But the threat from climate-change-induced flash flooding is accumulating, events that the environmental organization Greenpeace says are literally dissolving the cave paintings. Here's Li Zhao with Greenpeace's office in Beijing.

LI ZHAO: The paintings start to experience some processes of precipitating and buildup of salt on the wall paintings' surface. It makes the painting flaking and detachment.

FENG: Li collaborated with Wang and China's National Meteorological Administration on the new research. She says humidity reaches as high as 93% inside some caves. Museums usually keep humidity around 40% to protect artwork. The Dunhuang caves, however, are not inside the confines of a museum. And what saddens Li is not that the Dunhuang cave paintings will one day be reclaimed by time...

LI: Most people who are interested in the cultural heritage, they kind of know that the cultural heritage will someday completely disappear.

FENG: ...But rather, what is tragic to her is how quickly the art is fading on our watch.

LI: And this may happen just in one or two generations, so it's kind of sad to see them withering under our own eyes.

FENG: This time in the span of just one generation. Emily Feng, NPR News, Taipei. Transcript provided by NPR, Copyright NPR.