The world's oldest mummies have been around longer than the mummified pharaohs of Egypt and their ornate tombs — but the ravages of time, human development and climate change are putting these relics at risk.
Chile's Atacama Desert was once home to the Chincorro people, an ancient population that began mummifying their dead 5,000 years ago, two millennia before the Egyptians did, according to Bernando Arriaza, a professor at the University of Tarapaca.
The arid desert has preserved mummified remains and other clues in the environment that give archaeologists information about how the Chincorro people once lived.
The idea to mummify bodies likely came from watching other remains naturally undergo the process amid the desert's dry conditions. The mummified bodies were also decorated with reed blankets, clay masks, human hair and more, according to archaeologists.
While UNESCO has designated the region as a World Heritage Site, the declaration may not save all of the relics. Multiple museums, including the Miguel de Azapa Archaeological Museum in the ancient city of Arica, put the Chincorro culture on display. Some mummies and other relics are safely ensconced in those climate-controlled exhibits, but the remains still hidden in the arid desert remain at risk.
"If we have an increase in sea surface temperatures, for example, across the coast of northern Chile, that would increase atmospheric humidity," said Claudio LaTorre, a paleo-ecologist with the Catholic University of Chile. "And that in turn would generate decomposition, (in) places where you don't have decomposition today, and you would lose the mummies themselves."
Other clues that archaeologists can find in the environment may also be lost.
"Human-induced climate change is one aspect that we're really worried about, because it'll change a number of different aspects that are forming the desert today," said LaTorre.
Arriaza is working to raise awareness about the mummies, hoping that that will lead to even more preservation.
"It's a big, big challenge because you need to have resources," Arriaza said. "It's everybody's effort to a common goal, to preserve the site, to preserve the mummies."