Permafrost covers 20-25% of the Northern Hemisphere. Recent temperature increase in the Arctic and Subarctic is significantly higher than the global average. Climate simulations predict continuing warming and increased wildfires occurrence. This rapid change is already leading to permafrost degradation, inducing ground subsidence, affecting land usability and stability of infrastructure. An increase in active layer depth leads to increased water retention capacity, alters soil hydrology and groundwater drainage patterns. Besides, large amounts of carbon and other elements, previously trapped in permafrost, are released towards aquatic systems. Microorganisms actively convert newly available highly biodegradable organic carbon into greenhouse gases (CO2, CH4). As permafrost is known to contain vast amounts of frozen carbon, its thawing is a major risk because of the positive feedback on climate. Ultimately, climate change, through permafrost and habitat disturbance, affects local communities built on permafrost. A better understanding of the impacts of permafrost thaw on soils, surface/groundwater (critical zone) and carbon cycle as well as the controlling factors will contribute to the understanding of global climate feedback.