SEATTLE, Wash. — Some mosses in Canada’s eastern Arctic have long been entombed in ice. But now, rising temperatures have been melting that ice, bringing those mosses to light. By dating how long ago those mosses were buried, scientists now conclude that summertime temperatures in this region are the warmest they’ve been in tens of thousands of years.
“We were stunned,” said Gifford Miller of the University of Colorado Boulder. As a paleoclimatologist, he studies ancient climate. At some sites he studied, the emerging plants last saw the sun no less than 45,000 years ago. Some may have been buried for up to 115,000 years.
Miller described his findings October 22, here, at the Geological Society of America’s annual meeting.
As the planet warms, ice has been retreating on Baffin Island, in Canada’s far North. Miller’s team has been probing the plants unburied by this melting.
They collected an impressive number of samples, and their findings are very compelling, said Lee Corbett. She’s a geologist at the University of Vermont in Burlington who was not involved in the study. “It truly is an indication that humans are pushing the climate into a new regime,” she said. She points out it’s “one that modern, agriculture-based civilizations have never witnessed.”
Dating mosses
Miller’s group wanted to track the growth and retreat of Baffin Island’s ice cover. To do this, they have been hunting for remnants of scraggly mosses along the edges of the island’s retreating ice sheets.
The newly exposed mosses are dead. (At least for a year or two. Then they come alive again. That’s why Miller calls them “zombie” mosses.) The…
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