By Erin Wayman
The Arctic wasn’t always frozen tundra. About 3.6 million years ago, the far north was blanketed in boreal forests, and summers were 8 degrees Celsius warmer than they are today, geologists report May 9 in Science.
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Researchers pieced together that picture from sediments buried beneath Lake El’gygytgyn (pronounced EL-gih-git-gin), about 100 kilometers north of the Arctic Circle in northeastern Russia (SN: 11/20/10, p. 13). The sediments preserve the most complete history of Arctic climate on land over the last 3.6 million years.
“It’s an unprecedented record,” says study coauthor Julie Brigham-Grette, a geologist at the University of Massachusetts Amherst. “It gives us a way of envisioning what the future may hold.”