A crater lake in northeast Siberia is giving researchers a much better idea of how the world’s polar regions may change due to the increased saturation of carbon dioxide in our atmosphere. Formed by a one kilometer wide meteorite about 3.6 million years ago, the un-glaciated Lake El’gygytgyn lies 100 km north of the Arctic circle and provides the only unbroken climate record depicting the last time CO2 levels were as high as they are now. At the time, temperatures were 8C higher, the north was covered in lush tundra forests, and sea levels were 40 meters higher, The Guardian reports.

Prof Julie Brigham-Grette from the University of Massachusetts, Amherst led research to analyze sediments that had settled in the lake to determine what temperatures in the Arctic were like the last time CO2 levels were at their current levels – at roughly 440 parts per million – between 3.6 and 2.2 million years ago.

“It’s like deja vu,” she told The Guardian. “We have seen these warm periods before. Many people now agree this is where we are heading.”

Published in the journal Science, this research helps us to understand how temperature fluctuations impact the polar regions, which change faster than other regions. While some scientists suggest that the relative stagnancy of temperature changes over the past 15 years shows that the climate is not sensitive, Brigham-Grette says their research suggests otherwise.

“My feeling is we have underestimated the sensitivity, unless there are some feedbacks we don’t yet understand or we don’t get right in the models,” she told the paper.

While it will be some time before the NE Siberia is covered in Tundra forest again, Brigham-Grette says we will feel the impact of climate change soon. Indeed, we already are.

Via The Guardian

Lead image via Newswise; Diagram of Lake El’gygytgyn via AWI