As Chile's climate changes, the world's oldest mummies are turning moldy

Player utilities

Listen to the story.

Marco Werman: Here's a story about some unlikely victims of climate change: not polar bears stranded by melting ice or Pacific atolls battered by rising sea levels. I am talking about the Chinchorro mummies of South America in Northern Chile, where these mummies were discovered, Archaeologist's have been alarmed by what's happening to them. They are rapidly deteriorating turning to black ooze. Chilean Scientist turned to a Harvard Scientist for help; Ralph Mitchell, this is what he does: He investigates why ancient relics deteriorate. So, Chinchorro mummy, 7000 years old, seems like they've been preserved pretty well up in the Atacama Desert until now. What happened?


Ralph Mitchell: Well, my information from my colleagues in Chile, is that the fog began to roll in off Pacific about 10 years ago, the climate was changing and the mummies began to deteriorate and they couldn't work out why, and that's why they contacted me; I am a Microbiologist, so the interest was, is this a microbial process like an infection?


Werman: Right.


Mitchell: And they had about 200 mummies and they were fine until this fog started to roll in, and of course they saw deposition of moisture on the mummy surfaces. That deposition of moisture was associated with the beginning of deterioration of the skin of mummies.


Werman: So, your believe is that the micro-organisms embedded in that moisture is now, they're now eating away at the mummified skin?


Mitchell: Well, that's an interesting question, not necessarily in the moisture, You know, there are all around us indigenous micro-organisms. Our environment is full of non pathogenic micro-organisms. All you have to do is give them little moisture, look at the fruits and vegetables in your refrigerator, you know you see them going moldy, well where did the mold come from? Its all around us, so they are normal indigenous micro-organisms that were capable of decomposing skin. These were not rare, they were common normal micro-organisms. Give them a little moisture, and they will start growing.


Werman: So, here's a case that you cant solve with mothballs, what can you do?


Mitchell: Well, the message that Scientist in the Museum and the Archaeologist in the Museum are getting is you have to put in climate control, and to move in all the mummies into a climate controlled environment. You cannot leave them in the open anymore despite the fact that this area is one of the driest in the world.


Werman: Yeah, we're gonna say it speaks volumes of that kind of conversational properties of the Atacama Desert.


Mitchell: Yeah, well it raises an important issue, and that is our cultural heritage globally is at risk. One has to think that as the climate is changing around the world, what about our heritage materials, our archaeological sites,  our museums, our libraries, anything that's open is at risk from climate change. I mean, if we think about how mummies in Egypt, and how much we were real them as part of our history, this is an even more ancient part of our history knowing you look at the skin and you say, this is skin of the people who lived 7000 years ago, that is you know its all inspiring, and you don't want that lost, that's our memory.


Werman: Professor Emeritus at Harvard, Ralph Mitchell, great to have you on the program. Thank you.


Mitchell: Okay, you're welcome.