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Brain Food: Taking Earth's Temperature

PAGES Past Global Changes

The key to understanding recent climate changes could be at the bottom of Arctic lakes. That's what Darrell Kaufman believes. He's a paleoclimatologist at Northern Arizona University and studies core sediment samples of Arctic mud to get a glimpse of thousands of years of environmental changes.

"Often times we see evidence of volcanoes that have erupted," Kaufman says. "The ash of those eruptions are preserved in the sediment cores. Plus, there are bits of vegetation and bugs and other critters that have lived in the lake and have washed in from the landscape, and those are preserved in the sediment."

Credit NAU IDEA Lab
Darrell Kaufman and his research team taking sediment samples from an Arctic lake

Kaufman's research is the focus of the documentary, Taking Earth's Temperature. A film crew from NAU's IDEA Lab followed Kaufman and his team to Alaska. The researchers often worked in snowstorms, subzero temperatures and with an audience of grizzly bears. Kaufman says, "Climate changes of the past offer tremendous scientific value. Climate is a complicated system. It's not just about the greenhouse effect. We have oceans and atmosphere and the biosphere and the land surfaces that interact and complicate in wonderful ways that generate important feedback." He goes on to say, "There's good evidence that changes in the amount of snow and ice at high latitude can have a strong impact on climate, not just locally around the Arctic, but those changes can propagate around the world as well."

Kaufman says the film shows scientists working together to get a clearer picture about climate changes over the last millennia.