Ancient cave paintings in Indonesia, some dating back up to 45,000 years, have been irreparably damaged due to climate change.
Found on the Maros-Pangkep site on Sulawesi island, the limestone cave walls are adorned with hand stencils of red and mulberry tint, in addition to paintings of native mammals and human-animal hybrids.
Scientists believe these to be the earliest examples of cave art in the world. A painting of a Sulawesi warty pig, for example, has been deemed by scientists to be at least 45,500 years old.
These creations are fading fast, thanks to climate change. Even worse, the deterioration is irreversible, says Jillian Huntley, an archaeologist who has led a recent study into the impact of the climate crisis in the region.
Working with Australian and Indonesian researchers, Huntley, who is also a research fellow at the Place, Evolution and Rock Art Heritage Unit at Griffith University in Australia, published a paper in Nature on Thursday detailing these concerns.
As part of their work, researchers examined 11 caves in the Maros-Pangkep site. The paintings inside range from 20,000 to 45,000 years old. Changes in temperature and humidity have had their effect on the paintings, and even archaeologists from the 1950s have noticed that the works had started to peel.
However, the latest study from Huntley and her team reveals that man-made climate change, which brings about more severe periods of El Nino, a period of warming in the region, is accelerating the damage of the art.
These episodes of El Nino bring about drought and monsoon rains, consequently causing salts and minerals to crystallize on the cave walls, essentially stripping the surfaces where the works reside. As these crystal salts contract and expand due to the weather changes, the pressure can cause cracks to the paintings.
“In almost all sites containing early art, the hand stencils and figurative motifs are heavily affected by exfoliation of the limestone cave wall and ceiling surfaces that comprise the artists’ ‘canvas,’” the study states. The authors added that evidence points out that the “rate of exfoliation is increasing.”
In addition, the researchers state that the caves have been monitored on the same level as other prehistoric caves in Europe. The caves in the west do not have to endure the vast fluctuations in weather as those in tropical regions.
Currently, the Balai Pelestarian Cagar Budaya cultural heritage agency has launched a monitoring programme aid for documenting the state of the paintings, though researchers have urged for more support of the initiative.