This article examines the concept and essence of migration, environmental migration, as well as environmental migrants. The factors of migration according to the UN International Organization, the causes of environmental migration with illustrative examples of specific regions and countries are presented. The authors examined the types of migration and analyzed migration in the Russian Federation, as well as in the countries of Asia, North Africa, Europe, Australia and Oceania. The specifics of migration to warm countries and migration of the urban population to rural areas (ruralization) with their key factors, as well as the features of the outflow of highly qualified personnel from the Russian Federation, including emigration channels, reasons and plans of emigrants, are considered. In addition to the dynamics of emigration from Russia over the past 30 years, the article discusses the methodology for modeling migration processes and identifies the variables necessary to build a model of the migration process.