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BOB HIRSHON (host):
Siberia faces a meltdown. I’m Bob Hirshon and this is Science Update.
Even Siberia, one of the coldest places on Earth, is getting warmer. And once it hits a certain temperature, it could release over a billion more metric tons of carbon that’s now locked in frozen groundwater called permafrost. Oxford University geochemist Anton Vaks and his colleagues confirmed this by studying rock formations, called stalagmites and stalactites, in Siberian caves.
ANTON VAKS (University of Oxford, England):
And the stalagmites and stalactites cannot grow if the water above the cave is frozen.
Using geological dating, the researchers found that the stalactites and stalagmites formed almost entirely during a warm period about 400,000 years ago. Back then, global temperatures averaged less than one degree Celsius above today’s. Vaks says that suggests there’s a tipping point for melting the permafrost, and we’re getting closer and closer to crossing that line. I’m Bob Hirshon for AAAS, the Science Society.