Geological, Chemical and Physical Properties of Permafrost -- Arctic Permafrost Soils -- Antarctic Permafrost Soils -- Mountain Permafrost -- Biodiversity in Permafrost -- Very Old DNA -- Bacterial and Archaeal Diversity in Permafrost -- Viable Cyanobacteria and Green Algae from the Permafrost Darkness -- Fungi in Permafrost -- Ancient Protozoa Isolated from Permafrost -- Biological Activity in Permafrost -- Microbial Activity in Frozen Soils -- Anaerobic Ammonium Oxidation (Anammox) -- Genomic Insights into Cold Adaptation of Permafrost Bacteria -- Proteomic Insights: Cryoadaptation of Permafrost Bacteria -- Impact of Global Warming On Permafrost Properties -- Global Warming and Thermokarst -- Global Warming and Mountain Permafrost -- Global Warming and Carbon Dynamics in Permafrost Soils: Methane Production and Oxidation -- Global Warming and Dissolved Organic Carbon Release from Permafrost Soils -- Climate Change and Foundations of Buildings in Permafrost Regions -- Contaminants in Frozen Ground -- Migration of Petroleum in Permafrost-Affected Regions -- Remediation of Frozen Ground Contaminated with Petroleum Hydrocarbons: Feasibility and Limits -- Application of Reactive Barriers Operated in Frozen Ground -- Permafrost on Earth - A Model for Extraterrestrial Habitats -- Terrestrial Permafrost Models and Analogues of Martian Habitats and Inhabitants. Most of the Earth's biosphere is characterized by low temperatures. Vast areas (>20%) of the soil ecosystem are permanently frozen or are unfrozen for only a few weeks in summer. Permafrost regions occur at high latitudes and also at high ele- tions; a significant part of the global permafrost area is represented by mountains. Permafrost soils are of global interest, since a significant increase in temperature is predicted for polar regions. Global warming will have a great impact on these soils, especially in northern regions, since they contain large amounts of organic carbon and act as carbon sinks, and a temperature increase will result in a release of carbon into the atmosphere. Additionally, the intensified release of the clima- relevant tracer gas methane represents a potential environmental harzard. Significant numbers of viable microorganisms, including bacteria, archaea, p- totrophic cyanobacteria and green algae, fungi and protozoa, are present in per- frost, and the characteristics of these microorganisms reflect the unique and extreme conditions of the permafrost environment. Remarkably, these microorg- isms have been reported to be metabolically active at subzero temperatures, even down to ?20°C.