Study finds Laurentide Ice Sheet reversal halted by modern climate change
New research published in Science indicates the Laurentide Ice Sheet began re-expanding 2,000 years ago before anthropogenic warming interrupted the process in the 20th century.
A study conducted on the Barnes Ice Cap in the Canadian Arctic provides physical evidence that the Laurentide Ice Sheet—the largest remnant of the Pleistocene era—initiated a period of re-expansion approximately 2,000 years ago. Geologists conclude that this growth phase likely signaled the onset of a new glaciation period.
Lead author Nicolás Young of Columbia University’s Lamont-Doherty Earth Observatory notes that the Barnes Ice Cap serves as a crucial geological record. As the final fragment of the Laurentide dome, its core has preserved the thermal history of its base, allowing researchers to track the historical thinning and subsequent expansion cycles of the ice sheet.
The findings suggest that this cooling trend and ice accumulation were ongoing until roughly 1960. Researchers have now linked the cessation of this expansion to human-induced climate change, which reversed the trend and shifted the ice sheet back toward a state of retreat.