Rapid increase in West Siberia’s retrogressive thaw slumps since 1964 associated with Arctic winter warming

Abstract Retrogressive thaw slumps (RTSs) are key indicators of permafrost thaw in the West Siberian Arctic. Based on a new high-resolution remote sensing-derived, field-verified inventory of 6168 RTSs for the Yamal and Gydan peninsulas, we provide the first large-scale spatio-temporal and climate sensitivity analysis since 1964. In Gydan, RTS clusters are located at higher elevations, on rougher terrain, and in lake-rich areas, whereas such associations are weaker in Yamal. Temporal analysis of RTS using historical and modern satellite imagery for key sites (~ 6,103 km²) indicates that RTS numbers increased 23-fold since 1964, and initiation rates raised 26-fold. A discrete-time Bayesian hazards model identified summer maximum precipitation as the strongest short-term factor. However, winter warming was the dominant long-term driver, with an increase of 1.62 σ resulting in a 37-pp increase in annual initiation probability. RTS development in the region poses high risks to gas and transport infrastructure.