The importance of the Arctic in many fields of human activity strongly increased over the past decades. The academic scientific research demonstrates a 3-fold increase in the number of journal articles dealing with "Arctic": from 1,400 in 2000 to 4,200 in 2018. This increase is not fortuitous but certainly stems from double importance of Arctic regions for humanity. The first importance is the role that the Arctic plays in the on-going environmental changes, mostly linked to climate warming and environmental pollution. Here, the first key issues are the Arctic Ocean, ice melt, permafrost thaw, greenhouse gases emission, and organic carbon mobilization from soils to rivers. From the other hand, highly fragile Arctic ecosystems and biota are strongly affected by environmental pollution, be it organic compounds or toxic metals and radionuclides. The rising concern of humanity to the key role of the Arctic in climate regulation on the planetary scale and the extreme fragility of its ecosystem, biota and native population to on-going environmental change can certainly explain an explosive interest of scientific researchers to the Arctic in connection with 'climate change'. The second big issue of the Arctic is its eminent role in problems of natural resources. The Artic shelf contains vast amount of hydrocarbons (gas and oil), whereas the terrestrial polar regions, now liberating from ice, may turn out to be highly important sites of future ore industry. The importance of possibly ice-free Arctic Ocean as future maritime shipping routes will further enhance the accessibility of natural resources in this region. Taken together, this can be the main driving factors of almost exponential increase in the interest to natural resources in the Arctic over past few years. The present book addresses a wide variety of environmental, social and economic issues of the Arctic, in response to rising interest to this region in academic science, sociology and business. The 14 chapters represent state-of-the art reviews written by the experts on problems of native communities, climate change, political issues, implementation of large-scale projects, natural resources and conservation, environmental monitoring and assessment of pollution issues.