The AA. review the literature that has contributed to our understanding of patterns, processes and feedbacks, and the environmental consequences of thermokarst, focusing on hillslope, thaw lake and wetland processes. Advances in remote sensing
techniques, and their application in a broad suite of change detection studies, indicate recent increases in the rates and magnitude of thermokarst. Field-based studies and modelling have enhanced the knowledge of processes and feedbacks associated
with warming permafrost, changes in talik geometry and accelerated thaw slump activity, and thaw lake expansion. Thermokarst research provides an important context for studying the environmental implications of permafrost degradation. Investigation
of the interactions between thermokarst and hydrologic and ecological processes has improved knowledge of the feedbacks that accelerate change or lead to stabilisation in terrestrial and thaw lake environments. Finally, the influence of permafrost thaw on soil carbon
dynamics will be an important focus of thermokarst research because of feedbacks with the global climate system.