Glacial retreat in the Canadian Arctic has uncovered landscapes that haven't been ice-free in more than 40,000 years and the region may be experiencing its warmest century in 115,000 years, new University of Colorado Boulder research finds.
The study, published today in the journal Nature Communications, uses radiocarbon dating to determine the ages of plants collected at the edges of 30 ice caps on Baffin Island, west of Greenland. The island has experienced significant summertime warming in recent decades.
The Arctic is currently warming two to three times faster than the rest of the globe, so naturally, glaciers and ice caps are going to react faster.
Baffin is the world's fifth largest island, dominated by deeply incised fjords separated by high-elevation, low-relief plateaus. The thin, cold plateau ice acts as a kind of natural cold storage, preserving ancient moss and lichens in their original growth position for millennia.
In August, the researchers collected 48 plant samples from 30 different Baffin ice caps, encompassing a range of elevations and exposures. They also sampled quartz from each site in order to further establish the age and ice cover history of the landscape.
Once the samples were processed and radiocarbon dated back in labs at the Institute of Arctic and Alpine Research (INSTAAR) at CU Boulder and the University of California Irvine, the researchers found that these ancient plants at all 30 ice caps have likely been continuously covered by ice for at least the past 40,000 years.
When compared against temperature data reconstructed from Baffin and Greenland ice cores, the findings suggest that modern temperatures represent the warmest century for the region in 115,000 years and that Baffin could be completely ice-free within the next few centuries.