Permafrost is designated as an Essential Climate Variable (ECV) by the World Meteorological Organization (WMO) and is highly vulnerable to changing climate conditions. As occurrence of permafrost is mostly governed by climatic conditions and circumstances, hence, in most cases, warming of air causes permafrost to warm or thaw. The climate has been warming rapidly in recent decades, and as a result, the permafrost component of the cryosphere has changed drastically. Permafrost is a structurally heterogeneous environment with many varieties of permafrost in various geographical locations and climatic zones. Furthermore, there are variances between geographical locations in terms of topography, permafrost structure, organic-matter concentration, and age. However, the permafrost regions, that are diversely distributed, are less understood for its temporal changes. Permafrost characteristics that may act on local or global scales must be better understood. Hence in this work, we have taken the permafrost regions of the world and categorised based on their geographical zones (polar, temperate and tropical) and topography (mountainous, plain area). We took wide range of permafrost locales such as of Alaska, Canada, Russia, China, the European Alps, and Himalayan permafrost areas, existing in a variable environmental condition. For each of these locations we used Land Surface Temperature (LST), Mean Annual Air Temperature (MAAT), Mean Annual Ground Temperature (MAGT), snow depth, amount of Incoming Solar Radiation etc of Continuous, and Discontinuous Permafrost to study the temporal behaviour of Permafrost regions in the warming climate for the last 2 decades (2000 – 2020). The studies envelop a wide range of spatial and temporal scales. We took the observed data from the Global Terrestrial Network as well as the remotely sensed satellite data of Landsat 5, Landsat 8 and ERA Interim reanalysis product for analysing the changes that have happened in the past 20 years. Our result shows, the permafrost of polar regions exhibits a similar pattern while there is clear distinction in the permafrost of polar and tropical areas. The permafrost temperature of temperate mountainous region is warmer than polar planar regions. Thus, the effect of global warming on permafrost is quite evident but it is most pronounced in mountainous regions.

Permafrost; Land Surface Temperature; Mean Annual Temperature; Mean Annual Ground Temperature; Incoming Solar Radiation