Permafrost in Yukon Shows Current Warming is Unprecedented for Region

摘要

Current temperatures in Canada's north are warmer than they have been at any point in the last 13,600 years, a study in Nature Communications has found. Researchers from the University of Toronto Mississauga used radiocarbon dating and water isotopes preserved in permafrost beneath a central Yukon peatland to reconstruct summer temperatures over the last 13,600 years. During summer, new peat moss accumulates at the surface, and the top of permafrost, which lies at a constant depth of 58 cm below the surface, adjusts to the new surface. It preserves precipitation that filteredthrough the ground and froze at the top of permafrost during previous summers.