The thesis is devoted to deepening the theoretical and methodological foundations of the study of greening business on the basis of a circular economy to ensure sustainable tourism development and identifying ways to improve regulatory and investment policy of European countries in the market of circular goods and services. It is proved that the concept of the circular economy and the concept of sustainable tourism development have the same value priorities because their main goal is economic development, combined with high quality living conditions of the community and environmental protection. It is concluded that at the global level the manifestation of circular economy development is the formation of global environmental supply and value chains, at the macro level the problems of sustainable development are considered on the basis of circularity in the context of structural field changes and implementation of corporate strategies, at the micro level the consequences of greening of production and the problem of business adaptation to circular models, features of management, etc. are studied. The functional scheme of interrelations in the conceptual model of circular economy is formed, which complements the theoretical foundations of the concept with the types and forms of circularity of the relevant phases of the product life cycle. The indicator system of greening of business on the basis of circular economy on levels of management is offered. The current system of indicators includes project circularity indicators (micro-level), Eco-Innovation Index and Environmental Indicators Index (EPI) (macro-level), circular economy development indicators at the regional level (eco-innovation assessment methodology - meso level), IPAT formula and Global Index of Environmental Indicators (mega-level). Based on OECD data, the analysis of material consumption of human activities and domestic material consumption for 1970-2017 revealed signs of destructive impact of community life and business development on the environment (annual growth of material consumption per capita increased by 76 percent, well ahead population growth rates). In the development of international economic relations of the world economy, positive trends are identified in the formation of mechanisms for cooperation on decoupling, decarbonization of the economy and environmental protection. A comparative analysis of the dynamics of the Environmental Index as an indicator of the circular economy, showed the highest growth rates of business greening in Europe and Oceania (Australia and New Zealand), some countries in America (USA) and Asia (Japan, China), the lowest environmental status was found in Africa. Based on cluster analysis and expert assessments, the heterogeneity of the world's countries in terms of the level of distribution of the circular economy is substantiated (the countries are divided into three clusters in each of the world's megaregions). It is proven that 68% of European countries have high greening rates and belong to the first cluster of green economy, 9 EU countries have topped the ranking of greening and sustainable development over the past decade. The positive connection of the Index of the ecological state of the country's economy with the volume of research funding and the growth of revenues from the tourism business is determined. Strategies of water resources management of hotel industry companies are analyzed using the methodological approach "metrics of measuring the phases of circularity". It is proved that the majority of companies of the hotel industry implement adaptive development strategies and situationally implement circularity projects in water resources management (initial phase of circularity). The directions of development of international institutions in the context of global challenges to find collective solutions to overcome the negative impact on the economy of travelling and tourism, which include the development of conceptual provisions for carbon-neutral and socially sustainable development of international tourism, creating international Internet platforms for global discussion of tourism business transformation vectors , introduction of educational platforms for teaching and dissemination of new strategies for the development of the travel and tourism economy are summarized. A criterion approach to the selection of investment projects in the field of greening the business on the example of food industry, which provides requirements for the availability of key parameters of "circularity" is made. It is proved that the greening of production contributes to the spread of the circular economy not only in business, but also in the development of territories, ensuring their favorable image in the world community, intensifying tourist flows.
