Since 2008, the resilience of plants growing above the Far North's permafrost has declined widespread, even as satellite imagery shows continuous greening of vegetation cover. This contradiction, highlighted by an international study led by the University of Hong Kong, challenges the idea that a simple increase in biomass indicates robust ecological health. In other words, the tufts of grasses and shrubs colonizing frozen soils appear to grow more, but their capacity to withstand climate stresses — drought, late frosts, or fires — decreases markedly. The discovery, published in autumn 2026, draws on several decades of Earth observations and advanced predictive models.
What the study reveals: a reversal of resilience around 2008
The analysis shows that, from 2008 onward, the functional resilience metric — assessed from plant response to temperature and humidity variations — shifted to a downward trend across all northern permafrost zones, from Siberia to Alaska via Canada. This reversal is observed even as greenness indices, derived from satellite data, show a steady increase in photosynthesis and leaf area. The contrast between apparent greening and increased fragility indicates that ecosystems are not gaining in robustness, but merely in superficial cover.
The researchers emphasize that the loss of resilience is 'broad and homogeneous', affecting the coldest environments where permafrost thickens each decade. This uniformity suggests a global factor, likely linked to the continuous rise in average temperatures and the lengthening of the growing season, which exposes plants to more intense stresses late in the season. Thus, even as stems and leaves multiply, roots remain vulnerable to freeze-thaw cycles, compromising the plants' capacity to store carbon durably.