Canadian Arctic warmest in 115,000 years

Arctic temperatures are increasing faster than the Northern Hemisphere average due to strong self-reinforcing feedbacks unique to polar regions. This warming is causing rapid retreat of the region’s glaciers, especially in the Eastern Canadian Arctic, however the degree to which this recent warming is unprecedented remains unclear. To address this knowledge gap, Professor Nat Lifton (Earth, Atmospheric and Planetary Sciences) with collaborators from University of Colorado, Boulder and University of California, Irvine, used radiocarbon dating to determine the ages of plants collected at the edges of 30 ice caps on Baffin Island, west of Greenland. 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. The team’s 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.

Pendleton, S. L., G. H. Miller, N. Lifton, S. J. Lehman, J. Southon, S. E. Crump, and R. S. Anderson (2019). Rapidly receding Arctic Canada glaciers revealing landscapes continuously ice-covered for more than 40,000 years. Nature Communications, 10,: 445