Russia is fighting a mysterious anthrax outbreak in a remote corner of Siberia. Dozens of people are hospitalized; one child has died. The government airlifted some families out because more than 2,000 reindeer have been infected.
Officials don't know exactly how the outbreak started, but the current hypothesis is almost unbelievable: A heat wave has thawed the frozen soil there and with it, a reindeer carcass infected with anthrax decades ago.
Some scientists think this incident could be an example of what climate change may increasingly surface in the tundra.
There's likely to be more cases of anthrax resurfacing, says Birgitta Evengard, a microbiologist at Umea University in Sweden. That's because climate change is causing the temperature in the Arctic Circle to rise very quickly.
"It's rising about three times faster in the Arctic than in the rest of the world," she says. "And that means the ice is melting and the permafrost is thawing."
"So we really don't know what's buried up there," she says. "This is Pandora's box."