Climate change is erasing humanity?s oldest art

Eventually, the rocky canvas where people first drew images of their world 40,000 years ago falls apart in hand-sized flakes.To help understand the extent of the problem and confirm that salt is to blame, Griffith University archaeologist Jillian Huntley and her colleagues collected flakes from the walls and ceilings of 11 caves in the area, including Leang Timpuseng, home of the oldest hand stencil. Some of the local people who manage and protect the rock-art sites have done so for generations, and they report "more panel loss from exfoliation over recent decades than at any other time in living memory," wrote Huntley and her colleagues.That's no coincidence, according to Huntley and her colleagues.Here's how the process works: heavy monsoon rains drench Indonesia and the surrounding region from November to March, leaving behind water in cave systems, flooded rice fields, and brackish aquaculture ponds along the coast. The farming may also be indirectly threatening the world's oldest art."Holding surface water in these ways enhances humidity, prolonging the seasonal shrink and swell of geological salts, as well as leading to more mineral deposition," said Huntley. "All of which leads to rock art degradation." Regulations from Indonesia's government might help mitigate the problem, but conservators and policymakers need to better understand the scope and the local details of the problem before they can shape a policy that might help."Detailed monitoring of the rock art and microclimate on the Maros-Pangkep caves will help us quantify how rapidly the rock art is being impacted, and within the region where areas of higher impact occur," Huntley told Ars.Conservation agency BPCP has already started a small-scale program to monitor the condition of rock art in some of the area's caves, make 3D digital scans, and measure temperature, humidity, and chemical conditions inside the caves.