**5. Conclusions**

In the paper, we did not investigate the impact of anthropogenic factors, geopolitical and socio-economic processes, and the COVID-19 pandemic that also plays an important role in the sustainable development of coastal tourism on the Black Sea coasts of Russia. For instance, according to World Travel and Tourism Council [3], in 2020, due to the consequences of the COVID-19 pandemic, the total GDP contribution dropped from 10.4% to 5.5% (by 49.1% from USD 9.17 to 4.67 trillion), 62 million jobs were lost, representing a drop of 18.5%, leaving just 272 million employed across the tourism sector globally, compared to 334 million in 2019. The Council says: "The threat of job losses persists as many jobs are currently supported by governmen<sup>t</sup> retention schemes and reduced hours, which without a full recovery of Travel and Tourism could be lost. Domestic visitor spending decreased by 45%, while international visitor spending declined by an unprecedented 69.4%" [3].

In Russia, according to World Travel and Tourism Council [3], in 2020, the total contribution of travel and tourism to GDP dropped by 47% from USD 75.5 to 40.1 billion, 205.7 thousand people (−5.1%) lost their jobs in the tourist sector, international visitor spending dropped by 69.6% from USD 14.8 to 4.5 billion, and domestic visitor spending dropped by 43.9% from USD 37.9 to 21.3 billion. The share of international visitors concerns the main tourist destinations in Russia—Moscow and St.-Petersburg, while the domestic visitor share reflects mainly coastal tourism in the Black Sea. New COVID-19-related restrictions for tourists on the coasts of the Black Sea for the summer season of 2021 will continue to considerably impact socio-economic conditions in the Krasnodar Krai and Crimea.

The above-mentioned example shows that external factors like geopolitical and socioeconomic processes, global or domestic pandemics can suddenly cut one of the most important sectors of the national and global economy by around 50%. Regional climate change is one of these factors which affects the sustainable development of coastal tourism but is usually ignored. It would be wrong to believe that climate change is happening very slowly, so its effects can be felt in decades. The intensification of extreme weather conditions and negative natural processes in the atmosphere and the sea already today presents tourists with a serious choice—where is the best place to spend their next summer vacation? The answer to this question is not as obvious as it was in the previous decades.

The Russian Federation continues to invest significant funding in the development of infrastructure related to coastal tourism. On 2–5 June 2021, at the St.-Petersburg Economic Forum, a decision was taken to invest around USD 1.12 billion in the development of resorts and tourism in the Krasnodar Krai, in particular, in the construction of new resorts in Sochi and Anapa [76]. At the beginning of July 2021, the Russian Government announced a plan for the construction of a new tourist complex near Anapa called "New Anapa", which envisages the construction of 50 3–5 stars hotels, as well as restaurants, shops, roads, and other infrastructure which has to provide year-round tourist services. It is expected that it will provide 25,000 new jobs and will attract an additional 2–3 million tourists per year. This ambitious plan should be performed in three years and will cost

around USD 3.5 billion [77]. The Russian Ministry of Transport and Russian Railways are developing plans to construct a new railroad from Goryachy Klyuch to Sochi (which presently extends along the shoreline from Tuapse to Sochi) through mountains and a new automobile road from Dzhubga to Sochi (which also extends along the coast) several kilometers from the beach and urban infrastructure. The railway project will cost around USD 19 billion and will be completed by 2030, the automobile road project is estimated to be USD 32 billion and will be accomplished by 2035 [78]. As usual, all these plans did not take into account the negative factors that can arise in the near future from regional climate change. The comprehensive analysis of these factors would make it possible to make plans scientifically sound and investments much more effective.

We believe that this current research will serve as the first step in the multifactor complex study of this important matter. The present and future research are funded within the framework of the Russian Ministry of Science and Education Project "Comprehensive studies of the ecological state of waters of the coastal zone of the northeastern shelf of the Black Sea in the framework of participation in the international project DOORS" related to collaboration with the DOORS (Developing Optimal and Open Research Support system to unlock the potential for blue growth in the Black Sea) Project—a large international project started on 1 June 2021 within the framework of the Blue Growth thematic competition of the HORIZON-2020 Program of the European Union. The DOORS consortium includes 37 organizations from 17 countries, including the P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences. It is expected that based on the results of the project, specific practical recommendations will be prepared for optimization of maritime economic activity and the Blue Growth in all the Black Sea countries. We hope that our research related to climate change impacts on coastal tourism will be a base for such recommendations because coastal tourism is a major economic sector for all the Black Sea countries.

In this study, we focused on the assessment of climatic conditions for beach-based coastal tourism which makes it comfortable for tourists to spend time on the beach or in the water. This research has limitations as it has not covered many related aspects such as, for example: impact of climate change on wildlife in the region, detailed analysis of the impact of climate change on railway and road infrastructure, airports, and consequences for the touristic attractiveness of the region; the impact of climate change on yachting, cruising, boating, surfing, sup surfing, windsurfing, sailing, etc. This research also does not sugges<sup>t</sup> any managemen<sup>t</sup> strategies as this was out of the scope of our research. This paper has not either discussed the economic consequences of such climate change impacts on the region as this merits a separate study.

For future research, the authors are planning to develop the following directions of research: (1) detailed investigation of individual factors and their interannual variability; (2) investigation of local peculiarities for different parts of the Black Sea coast of Russia; (3) collaboration with other Black Sea countries in the framework of the DOORS Project to investigate the impact of climate change on their coastal zone; (4) elaboration of recommendations for local authorities and tourism business to overcome potential negative consequences of regional climate change.

**Author Contributions:** Conceptualization, E.A.K. and A.G.K.; methodology, A.G.K.; formal analysis, E.A.K. and A.G.K.; investigation, E.A.K. and A.G.K.; resources, A.G.K.; data curation, A.G.K.; writing—original draft preparation, E.A.K.; writing—review and editing, A.G.K.; visualization, E.A.K.; supervision, A.G.K.; project administration, A.G.K.; funding acquisition, A.G.K. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded in the framework of the Russian Ministry of Science and Education Project "Comprehensive studies of the ecological state of waters of the coastal zone of the northeastern shelf of the Black Sea in the framework of participation in the international project DOORS" performed under the Agreement on the provision of a gran<sup>t</sup> from the federal budget in the form of a subsidy 13.2251.21.0008. The APC was covered by the MDPI.

**Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable.

**Data Availability Statement:** All data used in the present analysis are freely available from the databases and websites mentioned in Materials and Methods Section.

**Acknowledgments:** We acknowledge collaboration with the DOORS Project (Grant Agreement ID 101000518) performed in the framework of the EU HORIZON-2020 Programme. We acknowledge the use of imagery from the Worldview Snapshots application (https://wvs.earthdata.nasa.gov), part of the Earth Observing System Data and Information System (EOSDIS). We are thankful to Dmitry M. Soloviev from Marine Hydrophysical Institute, who provided us with thermal imagery presenting recent upwelling events.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
