The book presents an analysis of the current state of the climate in the Barents Sea in 1979–2005. Using mathematical modeling for 2030–2039, 2050–2059, and 2090–2099. According to the global scenarios of climate change RCP4.5 and RCP8.5, a detailed comprehensive assessment of changes in the climatic parameters of the atmosphere and ocean is given. The most complete basic abiotic information was obtained to assess the impact of climate change on the ecosystems of the Barents Sea in the 21st century. For climatologists, geographers, biologists, as well as readers interested in the nature of the Barents Sea ecoregion and the prospects for its maintenance.