Unparalleled sediment record is "most continuous
archive" of ancient Arctic climate
The Arctic was very warm during a period roughly 3.5 to 2
million years ago--a time when research suggests that the level of carbon
dioxide in the atmosphere was roughly comparable to today's--leading to the
conclusion that relatively small fluctuations in carbon dioxide levels can have
a major influence on Arctic climate, according to a new analysis of the longest
terrestrial sediment core ever collected in the Arctic.
"One of our major findings is that the Arctic was very
warm in the middle Pliocene and Early Pleistocene--roughly 3.6 to 2.2 million
years ago--when others have suggested atmospheric carbon dioxide was not much
higher than levels we see today," said Julie Brigham-Grette, of the
University of Massachusetts Amherst.