A new 20-year field record from the Indigenous community of Umiujaq in Nunavik, Québec, provides rare long-term evidence of how permafrost degradation reshapes the land surface. The study, published in the Journal of Geophysical Research: Earth Surface, combined repeated ground surveys, LiDAR, and drone-based photography to track both ground temperature and landscape change from 2004 to 2024.
The researchers documented cumulative ground subsidence of up to 3.8 meters over the two decades. Temperature records showed that the active layer—the seasonally thawed zone above permafrost—thickened, the permafrost itself became thinner, and taliks, or unfrozen zones, developed within it. These changes were not steady; the authors found that subsidence accelerated in response to substantial climate warming that occurred between 1992 and the early 2000s.
The findings demonstrate how warming can drive large-scale geomorphological change, with direct consequences for ecosystems, carbon cycling, and northern infrastructure. The study also offers a monitoring framework that could be applied to other permafrost regions to better understand how different landscape types respond to a warming climate.