Scientists have previously revived ancient bacteria and prehistoric viruses that had been trapped. Scientists have a long record of resurrecting prehistoric viruses and ancient bacteria frozen in ice. However, as the climate crisis is melting ancient ice sheets worldwide, experts are growing concerned that prehistoric viruses could pose a risk to humanity. Other research has found 28 prehistoric viruses dating back 15,000 years in frozen ice cores. It's very difficult to keep samples pristine when extracting ancient ice, and even more difficult to conclusively date the ice.

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Persons: Lonnie Thompson, Jean, Michel Claverie, it's, Birgitta Evengård, It's, hadn't Organizations: Service, Privacy, The Ohio State University, Byrd, Climate Research, Umea University, CNN Locations: Yao, Tibetan, French, Antarctica, Russia