The Impact of a Global Crisis on Areas and Topics of Tourism Research

: Tourism research has placed considerable emphasis on the pandemic and its impact, which is not surprising given the impact of the pandemic on tourism. However, what speciﬁcally do tourism scholars write about the pandemic and its consequences for tourism? What new insights does the literature on COVID-19 provide to guide our practice in sustainable tourism? The pandemic can be seen as a sustainability challenge. Dealing with the pandemic and other sustainability challenges like climate change will not require exactly the same remedies, but the same kind, building resilience, adaptivity, ﬂexibility, collaboration, and co-creation. We thus argue that the literature on tourism and the pandemic may function as a “thermometer” of the way scholars view sustainability and tourism, and that exploring this literature gives us a space to reconsider our understanding of sustainable tourism. Therefore, we have conducted a literature review of the COVID-19 literature on tourism in 2020. A total of 87 articles, in 17 journals, from 4 databases were analyzed to explore how current scholars perceive COVID-19 and tourism, in light of sustainability perspectives. As a result, through the content analysis, this study has found six leading themes in COVID-19 and tourism and has provided valuable information with descriptive statistical analysis for its distributions by theory, methodology, and study area.


Introduction
Tourism research has long sought answers to what is and how to achieve sustainable tourism. The milestone progress includes three pillars of sustainable development and 17 United Nations (UN) sustainable development goals (SDGs). Then, in 2020, the tourism literature suddenly shifted heavily to the panic of the century that had taken over the world-COVID-19 and its effects. The latest update from Word Tourism Organization (UNWTO) in December 2020 stated: "the decline in the first ten months of 2020 represents 900 million fewer international tourist arrivals compared to the same period in 2019, and translates into a loss of US $935 billion in export revenues from international tourism, more than 10 times the loss in 2009 under the impact of the global economic crisis" [1]. Although UNWTO's extended scenarios for 2021-2024 point to a rebound in international tourism by the second half of 2021, a return to 2019 levels in terms of international arrivals could take 2 1 /2 to 4 years [1]. Given the impact of the pandemic on economic losses in countries, this shift is not surprising, but what specifically do tourism scholars write about the pandemic and its consequences for tourism? What new insights can the literature on COVID-19 provide to guide our practice in sustainable tourism?
Before answering these two questions, it is necessary to say something about views on what sustainable tourism is. Here we take as point of departure Saarinen (2013)'s typology of sustainable tourism, where he identifies three views. First, the view that sustainable tourism is about sustaining the business of tourism, i.e., giving priority to financial viability of the industry [2]. An underlying assumption must be that a viable tourism industry is good for society at large, providing jobs and tax revenue to the state to provide services to its citizens. The second view gives priority to environmental concerns, like carrying capacity, to put limits to tourism [2]. Even if concepts like carrying capacity are appealing, they have proven difficult to implement. Activities of tourism do not exist in a vacuum, but amidst other human activities, the effects of which become intertwined, so it is not easily possible to determine what environmental consequences come from what. The third view goes beyond the confines of the tourism industry when considering sustainability, and rather focuses on the places and people within which tourism takes place [2], i.e., the local community. This third view is the only one which allows more substantial rethinking of what tourism can and should be, even to the extent that refraining from tourism altogether could be the better option in some instances [2].
Then, why can the literature on COVID-19 guide us in the practice of sustainable tourism? On the one hand, voices have been heard arguing that as we deal with the effects of the pandemic, we run the risk of, but must not forget about, sustainability, as if the pandemic is not a sustainability issue in itself. The underlying assumption seems to be that companies (and societies) now must deal with economic recovery, and during such circumstances, they cannot afford to work with (expensive) sustainability solutions. Understanding the pandemic-induced challenges that have arisen and finding viable solutions to them can, however, be seen as working with sustainability. Whether a point of departure in the 17 UN sustainable development goals or the classic three pillars of sustainability (environmental, social, economic), it is clear that the pandemic has caused all sorts of unsustainable problems for tourism [3]. From this perspective, dealing with the effects of the pandemic is not something different than dealing with sustainability, but part of it.
On the other hand, there are other ways to view the nature of the sustainability issue of the COVID-19 pandemic. Originating outside of discussions of tourism is a view of sustainability problems as wicked problems (like [4,5]), i.e., involving a high degree of uncertainty, limited knowledge about the future and consequences of actions, and that it is not possible to find a singular right answer that will solve the problem, but that these problems will always be with us and the best we can do is to continuously try to deal with them, in ways that will never be optimal. Resilience, adaptivity, flexibility, collaboration, and co-creation become relevant ways of working with sustainability challenges in this view. Dealing with the pandemic, like dealing with other sustainability challenges (such as climate warming), will not require exactly the same remedies, but the same kind, building resilience, adaptivity, flexibility, collaboration, and co-creation.
From these two ways of understanding sustainability, we suggest that the pandemic in fact can be seen as a sustainability challenge and that the literature on tourism and the pandemic may function as a "thermometer" of the way scholars view sustainability and tourism, and that exploring this literature gives us a space to reconsider our understanding of sustainable tourism. Therefore, it is important to understand the large number of publications on tourism and the pandemic not only because it helps us make sense of what is going on within tourism research in this turbulent time, but also because from this new literature we may learn valuable lessons on how scholars conceive of tourism and sustainability, its problems, and their resolutions more broadly, outside the particular context of a pandemic.
As a result, we conducted a literature review of the COVID-19 literature in tourism in 2020. A total of 87 articles, in 17 journals, from 4 databases were found and analyzed, with the purpose of exploring how current scholars perceive COVID-19 and tourism, in light of sustainability perspectives. What perspective one has on sustainable tourism within Saarinen (2013)'s typology or other, will determine what one sees as solutions to problems. In our analysis of the COVID-19 and tourism literature, we analyzed what kind of solutions scholars propose, i.e., in what way they possibly see the pandemic as a sustainability challenge or not, and what view of sustainable tourism they propose.
The outline of this article is as follows: the next section presents the method used in this study; Sections 3 and 4 present the main findings based on content analysis and descriptive statistical analysis methods; Section 5 comprehensively discusses these main findings, responding to "What to hope?", "What is the challenge?", and "Where is the turning point?" Finally, Section 6 summarizes the main findings and states the limitations of this research are presented to invite further research.

Methodology
The purpose of this study is to identify the trends in COVID-19 and tourism literature. The literature on COVID-19 and tourism has proliferated in 2020, but a broad framework has not been mapped out to further develop and evaluate this emerging field of knowledge. A content analysis-based literature review is a good systematic review method "to map and assess the existing intellectual territory, and to specify a research question to develop the existing body of knowledge further", according to Tranfield et al. [6]. Tranfield et al. [6] pointed out that this method aims to identify "key scientific contributions" and to reduce bias and "provide collective insight" to a field. Ref. [7] also refers to it as "a systematic, explicit, and reproducible design for identifying, evaluating, and interpreting the existing body of recorded documents". Ref. [8] suggested this method as a structured and consistent procedure for generating reliable findings. Therefore, we used a content analysis-based literature review to conduct our study, according to the relevance of this method to our research purposes.
We utilized a six-stage refinement process suggested by Duan et al. [9] to collect data (see Figure 1). The six stages proposed by Durach et al. [10] are define research question, set inclusion and exclusion criteria, determine searching databases, apply criteria, synthesize relevant literatures, and report findings. First, we put forward the research question, which is the earliest step that can be found in the introduction. In order to ensure reliability and representativeness of the results [5], we defined a search string by querying a set of related keywords. The keywords and combinations identified and used in the online database search are "COVID-19" and "tourism". Both COVID-19 and the tourism industry are prevalent and popular research fields, which means that they already have a large amount of research results. With this in mind, we set the two keywords of "COVID-19" and "tourism" as an "and" relationship instead of an "or" relationship, aiming to discover the intersection of these two research fields. Since COVID-19 only spread from Asia to the rest of the world in the spring of 2020, research related to COVID-19 only appeared in January 2020 and with some exceptions, the research hardly involves the publication of books. In order to ensure the academic quality and relevance of the data, we excluded sources other than journals. Taking into account the article's audience area, popularity, article quality, and relevance to tourism research, we applied the defined search string to four mainstream publishers (Taylor & Francis, Wiley, Elsevier, and MDPI). The online databases of these four publishers were chosen because they are some of the most popular databases highly relevant to the tourism industry. The reason for using the publisher's online database for search instead of other broader search engines such as Web of Science, Scopus, Google Scholar is to enable the selection of purely scientific articles. Focusing on purely scientific papers was to be achieved as the goal of the research. It was decided not to include industry reports and strategic documents of the development of cities [8].
In the third step, we excluded duplicate papers and applied inclusion and exclusion criteria (see Table 1). As of the end of data collection on 4 November 2020, we found a total of 87 journal articles with the keywords of "COVID-19" and "tourism" in the online databases of four major publishing houses (see Table 2). Due to the emerging nature of COVID-19 research, we did not purposely limit the time of publication. The articles found were published from January 2020 to November 2020. The final 87 papers were classified and evaluated through content analysis, a systematic and objective research method that has been used to quantify phenomena, documents, or communicate [8].

Inclusion Exclusion Published in English language
Published in other languages Papers contain identified keywords Papers focused on any industry rather than the intersection of COVID-19 and tourism Peer review paper Other type of paper like business news.

Inclusion Exclusion
Published in English language Published in other languages Papers contain identified keywords Papers focused on any industry rather than the intersection of COVID-19 and tourism Peer review paper Other type of paper like business news.
After content analysis, we employed summative and thematic content analyses to adequately address its objectives. Descriptive analysis is the first insight into all papers to provide basic information about the selected paper [9]. The attributes of selected papers involved (i.e., time, region, methodology, and theories) were exported into Microsoft Excel to add some noteworthy supplementary information to the content analysis results. For example, statistics on the theories can reflect which theories are commonly applied at the intersection of COVID-19 and tourism. Microsoft Excel was utilized to rigorously execute the summative analysis, while thematic analysis was assisted by constant comparison. Content analysis usually focuses on the systematic collection, classification, analysis, and compilation of most non-digital data to make valid inferences, providing a comprehensive understanding of the phenomenon under investigation [11]. As a result, content analysis is performed to extract, understand, organize, synthesize, and capture the relevant information contained in the selected account [11]. The limitations of the method are discussed at the end of this study.

Content Analysis Results: Leading Themes
This section explains the main findings of content analysis. Through the direct correlation between the content of the literature and the theme, this study defines six leading themes of COVID-19 and tourism literature, namely (1) government crisis management; (2) tourist perception and decision-making; (3) tourism service providers; (4) new normal; (5) tourism research; and (6) inequality.

Government Crisis Management
This theme revolves around the tourism policy planning before the crisis, the response measures during the crisis, and the tourism recovery strategy after the crisis. The results are summarized in Tables 3-5. Table 3. Government crisis management: before the crisis.

Measures Example Source
Tourism policy planning Formulate tourism development policies [12] 3.1.1. Government Crisis Management: Before the Crisis From the perspective of government crisis management, before the crisis, [12] used the augmented mean group (AMG) and the common correlated effects mean group (CCEMG) estimation techniques to study the potential moderating effect of the COVID-19 outbreak on the relationship between geopolitical risks and tourism, and proposed that before the crisis, policy makers should formulate a crisis management plan to protect the tourism industry when formulating the policy direction of tourism development.

Measures Example Source
Financial support Insurance and subsidy programs for employees; support the survival of the hotel and airline industry [3,[13][14][15][16][17] Play the function of the informal sector Cooperation between the informal sector and government departments; provide microfinance; provide bank insurance [18,19] Prioritize actions Quick response to the tourism industry in crisis [13,15] Formulate public policy Prohibit or restrict the arrival of giant cruise ships and promote the development of small cruise ships; issue policies to support the aviation and hotel industry; government supervision of policy implementation [12,20,21]

Measures Example Source
Support domestic and regional tourism Adopt tax reduction measures for domestic tourism; provide digital coupons to support tourism; reduce dependence on long-distance tourists and support regional and VFR (visiting friends and relatives) tourism [18,22,23] Restore market confidence Use big data to investigate the perception of tourists; ensure the safety of destination travel [22,24,25] Carry out intergovernmental cooperation Establish common standards and sanitation agreements between governments, and set up international safe tourism border areas [21,26] Redefine community-based tourism Redefine and reposition the tourism industry according to the rights and interests of local people; ensure the participation of indigenous people and protect their right to know; incorporate indigenous values into national tourism policy planning [18,27] Conduct recovery marketing Promote tourists on the safety of the destination; promote the image of the destination through social media [12] 3.1.

Government Crisis Management: In Crisis
In times of crisis, Chen et al. [13] argued that the government needs to take countermeasures to save the loss of domestic tourism. First, the government needs to provide financial support to the travel service providers affected by the crisis, especially the hotel and airline industry, and the employees involved. This involves providing public funds on preferential terms, especially to community companies that have low solvency and may have difficulty obtaining loans from commercial banks. However, government support currently depends on voluntary disclosure by companies. Williams [14] found that even if the government provides short-term financial support to the affected workers and enterprises, this can only offset the loss of income declared by the enterprises, employees, and self-employed individuals. Businesses, employees, and self-employed individuals in the undeclared economy will not receive this support.
In addition to the government sector, second, the informal sector is important for tourism development in some developing countries, providing support such as microcredit to local entrepreneurs. Third, Yeh [15] found that the key to success in tourism recovery strategy against COVID-19 pandemic is to prioritize tasks. Ref. [13] further argued that the tourism industry is prioritized by sentiment, because the strategic deployment of national institutions and the rapid response of the tourism industry may help strengthen the public's trust in the organization and affect the public's assessment and crisis communication effects.
Fourth, the government needs to formulate policies to play its role of encouragement, control, and supervision. From the perspective of cruise travel suspended due to COVID-19, Renaud [20] proposed that the host country should rely on national and regional governance to gradually prohibit or restrict the arrival of giant cruise ships, the purpose of which is to promote policies for the development of small cruise tourism and develop fleets controlled by local participants.

Government Crisis Management: After the Crisis
When the crisis enters the next life cycle, the government's management strategy needs to shift to the recovery of the tourism market. Compared with the recovery of the complex international tourism market, domestic tourism and regional tourism will be an effective alternative in the short term. For example, Foo et al. [23] concluded that the Malaysian government has issued incentives to promote domestic tourism, such as personal income tax relief of up to RM1000 for domestic tourism and digital coupons of up to RM100 per person for domestic flights, railway travel, and hotel accommodation.
In addition, the government should also improve the infrastructure and service quality of domestic tourism to attract tourists. The challenge for the tourism industry in most developing countries is that accommodation and others usually focus on the international market (five-star hotels, high-end hunting trips) but there is a huge gap between them and other services applicable to domestic and regional travelers, according to Rogerson and Baum [18].
Second, the government should focus on restoring confidence in the market, including surveys of tourists' perceptions and guarantees for tourism safety. Given that tourists' personal safety fears related to personal and public health hinder consumers' confidence in travel, all destinations around the world will face the challenge of establishing market security. These safety measures are designed to protect tourists, tourism industry workers, and local communities. Tran et al. [24] proposed that the government should use big data to investigate the perception of tourists and ensure the safety of travel in the destination.
Third, for significantly raised community-based tourism in many developing countries, the community needs to consider whether it should reorganize its tourism products, re-adjust its products to adapt to new (possibly domestic) markets, or exit the tourism industry completely to adapt to the changing needs of tourists after COVID-19, according to Rogerson and Baum [18]. Higgins-Desbiolles [27] proposed that the government needs a community-centric tourism framework, that is, to redefine and position the tourism industry based on the rights of local communities and local people.
Fourth, after the crisis, policy makers should adopt active recovery marketing strategies to re-establish the image of safety and attractiveness required by tourists to ensure the restoration of competitiveness and economic recovery, according to [12].

Tourist Perception and Decision-Making
Tourist perception and decision-making are the second leading themes in the COVID-19 and tourism literature, accounting for 21.84% of all literature. This theme revolves around investigating tourists' current attitudes and perceptions of travel under COVID-19 (61.11% of the theme), and the change in the values of tourists from COVID-19 (38.89% of the theme). The results are summarized in Table 6.
Under this theme, on the one hand, many scholars have conducted surveys on tourists' current reactions to travel under COVID-19 and found that the negative impact of COVID-19 has significantly affected the health risks perceived by tourists (for example, [25,[28][29][30]). As a result, tourists' avoidance of travel during the health crisis is caused. Health risks and psychological risks are important entry points and health risks are the main concern of tourists. These risks may affect personal well-being, leading to tourists' fear, travel anxiety, and risk attitudes, which will make tourists have a strong negative emotional response to travel. Table 6. Tourists' perception and decision-making under COVID-19.

Angle
Example Source Tourists' current attitudes and perceptions of travel under COVID-19 Tourists' willingness to return to the destination and willingness to pay; tourists' trust in the destination; tourists' attitude, risk perception, and crisis awareness [25,[28][29][30][31] The change in the values of tourists from COVID-19 Mindfulness; attitudes of tourists to hosts; social responsibility and civic values; understanding of sustainability; attitudes to sustainable products and destinations [13,19] On the other hand, scholars have found that in general, COVID-19 will prompt enough individuals, companies, and governments to adopt new ways of thinking, behavior, and operations that are more consistent with the sustainable development goals (like [13,32]). Therefore, they further proposed that if the tourism industry can take the expansion and stimulation of global awareness as the important value of the products and experiences it provides, then this function of the tourism industry should be strengthened (like [33,34]). For example, Stankov et al. [33] called for COVID-19 to be seen as a wake-up call and an opportunity for the tourism industry to accept the mindfulness movement, so that people believe that mindfulness has the ability to reflect current problems. As a result, a more compassionate and far-reaching tourism path for hosts and guests will be opened.

Travel Service Provider
Travel service providers are the third leading theme in the COVID-19 and tourism industry literature, accounting for 19.54% of all literature. Travel service providers include the airline industry, hotels, peer-to-peer (p2p) network service providers, and others. This theme revolves around how travel service providers lay a foundation for their capabilities before the crisis, how to manage the crisis during the crisis, and how to gain the trust of the market after the crisis. The results are summarized in Tables 7-9. Table 7. Travel service providers: before the crisis.

Strategy Example Source
Build trust and commitment Build trust and commitment with agents, tourists, and other stakeholders [21] Employee training Through multi-skill training for employees, employees are able to participate in multiple job roles [35] Before the crisis, compared with operational risks, companies in the tourism supply chain were interconnected in a complex pattern, which led from one type of risk to another. In order to mitigate the risks of the tourism supply chain and improve its resilience, González-Torres et al. [21] proposed that tourism service providers should build trust with agents, tourists, and other stakeholders before the crisis, in order to explore key coordination areas (finance, labor, demand, supply, and supervision) with these actors in the event of economic disruption. In addition, in this crisis, multi-skills are considered as a potential solution to reduce redundancy and retain employees for a long time. This reflects the need for managers to recognize the importance of employees participating in multiple job roles, which is expected to become the norm in the hotel and tourism industry. As Kaushal and Srivastava [35] put forward, travel service providers that conduct multi-skilled training for their employees before the crisis will reduce the corporate risk of losing a large number of employees and the pressure on employees of unemployment during a crisis. Table 8. Travel service providers: in the crisis.

Strategy Example Source
Obtain government support Seek support from government and non-government departments and actively communicate with them [16,17] Fulfill corporate social responsibility Insist on not increasing prices during the crisis; protect the interests of customers (promptly terminate the travel contract; full refunds; protect the legitimate interests of tourists); ease the pressure on employees and ensure their happiness [3,13,17,36] Cooperation, learning, and knowledge sharing Cooperation within and between corporate departments; cooperation with other stakeholders such as government, suppliers, and educational institutions, information sharing, and joint management [21,35] Business management and innovation Enterprise business diversification; product, service, and management innovation; market segmentation [13,37] Financial management Flexible financial management arrangements; multi-asset portfolio to diversify risks [21,38] Table 9. Travel service providers: after the crisis.

Strategy Example Source
Analyze the market Improve big data analysis and evidence-based decision-making skills; conduct customer surveys to understand the market [29,39] Establish sanitation measures and punishment methods Ensure the health and safety of employees and consumers; set penalties for violations of health and safety [35] Marketing, forecasting, and sales plan Utilize social media for marketing; flexibly adjust hotel sales plans; predict and evaluate risks [21,35,40] During the crisis, first, since mid-March 2020, operators have lost a large part of their revenue, which makes people worry about their financial stability and ability to restore services. Many tour operators may require direct or indirect government support. Although government support is a pragmatic way to ensure that the impact is at least partially mitigated, inappropriate government intervention will bring more negative effects to the tourism industry. In the aviation industry, most governments place high priority on the interconnection of air transportation to protect economic activities and employment in related sectors such as aviation and tourism. As a response to this epidemic, government support is likely to strengthen the role of national advocates and enable them to gain a higher market share, thereby harming smaller players who cannot attract much private or public funding, according to Forsyth et al. [17]. In this regard, Abate et al. [16] proposed that the partial or full nationalization of airlines with government support may be positive because it may be a lever to introduce social and environmental goals. In the event of economic disruption, negotiation and coordination are essential for more effective implementation of measures. Kaushal and Srivastava [35] argued that changing from a fair relationship to a coordinated relationship will mean that the government will give more consideration to the characteristics, needs, and actual impact of travel service providers.
Second, scholars call for tourism companies to perform corporate social responsibilities in a crisis to enhance their corporate reputation and image, thereby laying a foundation for business recovery after the crisis. Chen et al. [13] take the recovery of China's domestic tourism market as an example and conclude that China's successful experience is that tourism companies have quickly taken countermeasures, such as, terminating the travel contract, providing tourists with a full refund, and exempting related handling fees due to changes and extensions. Chen et al. [13] concluded that these performances effectively resolved tourist complaints and travel disputes caused by COVID-19 and protected the legitimate rights and interests of tourists. Given that some visitors have been temporarily stranded by the COVID-19 outbreak, there may be anxiety and panic at first. The hotel provides room service for guests and arranges staff to take care of their physical condition and make them feel at home. The host's care for the guests during the crisis helps to enhance the confidence of the tourists, according to Chen et al. [13]. On the contrary, many travel service providers have increased the prices of services or products in order to recover costs. Forsyth et al. [17] argued that from the perspective of public policy, price increases in the crisis are considered undesirable because they will further damage the long-term viability of tourism service providers and the tourism industry, as well as the broader economic benefit.
Third, tourism companies have actively carried out industry-wide self-rescue operations under the tourism crisis caused by COVID-19, including knowledge learning, cooperative management, and business diversification to improve long-term viability. The crisis has brought lessons to every stakeholder in the tourism supply chain, and the sharing of knowledge and joint management of the crisis will benefit the recovery of the entire industry.
In response to consumers' concern for sustainable and environmentally friendly tourism products and services, tourism service providers upgrade their businesses through market segmentation, and diversify their risks through multi-asset portfolios through corporate business diversification. For example, Chen et al. [13] took the hotel industry as an example and proposed that the franchise hotel industry can use its own collection of intangible assets (such as unique company capabilities, brand image, physical assets, or human resources) in different markets and internally to reduce the risk of crisis and monitor costs [41]. Crisis and opportunity often coexist. During the crisis, the tourism industry can proactively provide corresponding services according to the needs of consumers. For example, Chen et al. [42] proposed that, considering that people are unwilling to eat out during the outbreak, hotels can provide nearby offices and residents with packed lunches, fresh vegetables, and fruits. In addition, hotels can also launch long-term accommodation packages and longer-term promotional activities to encourage local consumption. These methods can not only meet people's needs during the epidemic, but also open up new hotel revenue channels.
In the COVID-19 crisis, big data has proven to be more relevant in the tourism sector than ever before. Lew et al. [39] showed how big data can provide timely granular data in highly turbulent conditions, and found that in this crisis, DMO (destination management organization) managers have realized the importance of understanding market behavior and acting quickly to restore confidence and stimulate demand. Therefore, Lew et al. [39] concluded that destination management organizations need to improve their big data analysis and evidence-based decision-making skills. Similarly, Li et al. [29] also proposed that after the crisis, destinations should investigate the perception of the tourist market to understand the market. In view of tourists' fear of the safety of destinations, Rogerson and Baum [18] claimed that clearly ensuring the health and safety of employees and consumers and setting penalties for violations of health and safety will greatly enhance tourists' sense of security in their destinations. In addition, travel service providers should use social media to actively stimulate consumption and actively predict risk assessments.

New Normal
"New normal" is the fourth leading theme in the COVID-19 and tourism literature, accounting for 13.79% of all literature. "New normal" discusses the future of tourism after COVID-19. Will it return to business as usual or transform in another direction? Scholars maintain an inconsistent attitude towards this. The results are summarized in Table 10. There is no normal way of doing things, only standardized ways of doing things. [23,48] In this theme, 50% of scholars hold a neutral attitude, that is, they do not deny the possibility of the transformation of the tourism industry after COVID-19, but assert that the possibility of success is based on certain conditions and it is difficult to achieve these conditions. Sheller [51] argued that in the context of COVID-19, although local communities are severely affected by the loss of livelihoods, there is an opportunity to rebuild tourism with a triple bottom line that will ensure a more resilient and sustainable local economy. This reconstruction has the potential to revive the short-circuit economy [52], reinvigorate environmental hopes and remedies [53], and promote institutional innovation [48], but this path requires the leadership and creativity of scholars, researchers, and educators [51].
The world is struggling to deal with the real problems brought about by this global epidemic, and it also gives us the opportunity to rethink what the tourism industry will look like in the next few decades. Brouder [48] explained that the core concepts, especially path dependence/creation and institutional inertia/innovation, provide path variables for the development of travel and tourism under the influence of the new crown virus, and thus concluded that only if tourism demand and tourism supply have sufficient institutional innovation to cultivate a new path, tourism transformation can be truly realized. However, Brouder [48] claimed that whether the current institutional innovation will cause fundamental changes in the tourism industry remains to be seen. Cheer's [54] attitude towards the new normal is that COVID-19 awakens an opportunity to reshape the tourism industry to make it more sustainable, more inclusive, and more catering for many tourism stakeholders, but human prosperity requires a more detailed set of methods to measure the tourism impact of local communities. Therefore, considering that the possibility of recovering from COVID-19 may eventually be roughly the same, Hall [50] called on destination governments and stakeholders to exercise caution. 33.33% of the scholars maintain a positive attitude towards the future of the tourism industry, believing that COVID-19 has brought unprecedented opportunities to the transformation of the tourism industry and will ultimately realize the transformation of the tourism industry. COVID-19 is an "unprecedented crisis", exposing the trap of over-consumption economic growth and development models. The degree of direct impact on the econ-omy has broken the myths of "catch up with development" and "permanent growth", bringing unexpected degrowth and providing opportunities for economic and social reconstruction to a certain extent [45]. As claimed by Tomassini and Cavagnaro [46], along with sustainability-conscious citizens, consumers, producers, travelers, entrepreneurs, and community leaders calling for and taking action to achieve the necessary transition to a renewable paradigm and a regenerative economic system, new ways of being, knowing, and acting are emerging. Based on a natural cycle that can be restored and regenerated, this recycling method combines regenerative agriculture and transformational tourism based on the practice of reclaimed land, with the hope of permanently resetting the global tourism system [46]. However, 16.67% of scholars still maintain a negative attitude, believing that the "new normal" of path innovation is a short-term illusion, and the deep-rooted nature of the tourism industry will organize the transformation of the tourism industry. Brouder [48] argued that unless there is "enough institutional innovation", otherwise the transformation may still be a fantasy [23]. Brouder [55] explained: "The possibility of tourism transformation is very low. There is evidence that the sustainable tourism industry in the past was eventually cancelled by the mainstream development path. This result is daunting and frustrating." Ateljevic [52] pointed out that there has never been a "normal" way of doing things, but a "standardized" way of doing things. Similarly, Hall et al. [50] concluded that "the changes in the tourism industry due to COVID-19 will be unbalanced in time and space." That is, although we may see a new kind of regionalism, it may be the old and new travel method. It can be seen that these scholars did not question short-term changes in the tourism industry, but claimed that the challenge would lie in embedding a new normal for long-term and greater benefits Therefore, to what extent COVID-19 will affect the creation of the path and what the new path is remains unresolved.

Tourism Research
Tourism research is the fifth leading theme in COVID-19 and tourism literature, accounting for 12.64% of all literature. The results are summarized in Table 11. Table 11. Tourism research.

Perspective Argument Source
The importance of tourism research and education • Tourism research and education are important for the management of people's values, community goals, and government goals in the COVID-19 crisis.

•
The debate over whether the tourism industry will change after COVID-19 is the best contest of ideas. • Scholars should work together and share knowledge. [18,27,[56][57][58][59] Adhere to the principles of impartiality and criticality in COVID-19 and tourism research Researchers should abandon selfish ideas, critically change people's views on tourism, and do fair research. [42,[60][61][62] Set the priority of tourism research Other crises cannot be ignored, such as Antarctic scientific expeditions and oil spills on cruise ships. [63,64] In this theme, scholars emphasized the importance of tourism research and education for the management of people's values, community goals, and government goals during the COVID-19 crisis, thus calling on scholars to play their role. Universities have always played a leading role in society. Academia, along with other professional bodies, should have played a greater role in informing mayors, city governments, and city officials about the importance of managing community goals in how to establish community goals, improve governance, formulate tourism strategies, and revise policies that reflect goals and principles [65]. Small-and medium-sized enterprises urgently need help from academics, especially in developing reconfigured survivability and entrepreneurial skills to adapt to new emergencies. The COVID-19 crisis has inspired some travel scholars to change their thinking. This is a moment of great potential, because the debate triggered under the heading "War in Tourism" is regarded as the best ideological contest on tourism in a struggle between ideas that support the status quo by restoring business as usual and ideas that envision greater sustainability, fairness, and justice [27]. Therefore, Wen et al. [59] call on medical/health and social researchers to work together to combat the global COVID-19 crisis.
In view of the importance of scholars in transforming the tourism industry to sustainable development in the crisis, scholars also emphasized that the research on COVID-19 and tourism should eliminate selfish perspectives and critically analyze reality. As Benjamin et al. [34] appealed, the key to constructing this kind of thinking requires us as researchers and educators to abandon egoism and critically change people's understanding of tourism, making it truly fair focus.
In addition, some scholars have also called for setting the priority of tourism research, not to ignore crises other than COVID-19. COVID-19 is indeed the world's greatest public health threat in the 21st century. Due to the global economic recession caused by COVID-19 and the diversion of research attention, some research on other crises that are occurring has been forced to stop or slow down. For example, Frame [63] reviewed the potential impact of COVID-19 on Antarctica through tourism and scientific research and the Antarctic Treaty System, and found that in the short term to April 2021, Antarctic tourism and field research will be greatly reduced. Likewise, Junior [64] found that due to COVID-19 and the economic crisis, efforts to understand and resolve the oil spill crisis off the coast of Brazil had to be stopped (or slowed down), leaving the ecosystem and society with no answers to determine the cause of the problem and understand how to mitigate its impact on the community and the environment.

Inequality
Inequality is the sixth leading theme in the COVID-19 and tourism literature, accounting for 11.49% of all literature. The theme encompasses four dimensions of inequality, including community inequality in tourism (40% of the literature on the theme); inequality between developing and developed countries (30% of the literature on the theme); inequality in the nature of tourism (20% of the literature on the theme); and the inequality of tourism development within the country (10% of the literature on the theme). The results are summarized in Table 12. Inequality within the country Colonialism and inter-ethnic inequality that still exists. [67] Inequality in the nature of tourism For a long time, tourism has been capitalist, which is the opposite of non-capitalist tourism. [55,68] Community inequality in tourism • Community members should strive to control their own territory, in order to change from "growth for development" to "reduction for livable". • Community should actively participate in tourism management and strive for community welfare and the right to know.

•
Community-based tourism should be innovative and diversified. [20,52,69,70] In this theme, the inequality of the community in the tourism industry has been the most studied. The community is an important part of the sustainable development of tourism. The leakage of tourism economy, the uneven distribution of tourism benefits, and the lack of resources have caused the unequal status of the community in the tourism industry. The impact of COVID-19 is long-term and will have intergenerational effects on both indigenous and non-indigenous people. Carr [70] conducted research on Māori people's response to COVID-19, and proposed that Māori values need to be incorporated into parliamentary policies and bills such as whanaungatanga (kinship and belonging), kaitiakitanga (environmental guardianship and responsibility), and manaakitanga (respect, care, and hospitality), etc., and multicultural values should be incorporated into the government's response measures and planning work to ensure that tourism suppliers, tourists, and hosts have a fairer future and a positive experience. In addition, the development of cruise tourism has exacerbated the unequal status of the community in the tourism industry. Tourists leave all their expenses on the cruise ship, causing environmental damage to the community and disrespect for culture. Global mobility is a necessary condition for the development of mass cruise tourism, but it may also become a weakness of the industry, as evidenced by the reduction in mobility under COVID-19. Therefore, the concepts of global mobility and local mobility can be used to criticize the power relationship between mass cruise tourism and destination communities. Renaud [20] proposed that destination communities should make good use of the characteristics of mass cruise tourism's dependence on global mobility, strive to adjust the balance of power in a direction that is beneficial to them, and promote the leverage of local mobility. At the same time, Renaud [20] also specifically pointed out that the destination community must also adopt a thorough solution to control its own territory, so as to realize the transition from "growth for development" to "reduced for livability".
Second, the mistrust between countries that was shown during COVID-19 will be retributed in the later stages of the health crisis. The establishment of a new international order will need to consider a good balance between political totalitarianism and a free market economy, as both show different advantages. A living example is that, as one of the most populous developing countries in the world, China has rescued its citizens from COVID-19 deaths to a considerable level and is gradually resuming tourism, while the United States, Britain, Italy, Spain, and France cannot alleviate the crisis with its best medical insurance, market, and education [66]. Political totalitarianism and liberal market economy debates will be extended to the tourism industry, which may change the attitude and decision-making of tourists to travel in developing and developed countries after COVID-19.
Third, in addition to inequality between countries, there are also inequalities within countries that have an impact on the post-COVID-19 tourism industry. Gallego and Font [67] claimed that within the country, there have been long-standing disputes between tourists, immigrants, and residents due to differences, colonialism, racial inequality, white supremacy, and neoliberalism. This model is unfair and unsustainable. Such disputes have been intensified by increasing community and ecological pressures brought about by tourism. Gallego and Font [67] conducted research on the future of tourism in the Caribbean and concluded that instead of eager to return to cruise ships and rebuild bankrupt hotels, we should rather work with communities in the Caribbean to reimagine a regenerative economy and a resilient ecology, so that these economies and resilience can be based on fairer mobility and connections.
These inequalities may ultimately be attributed to the nature of tourism. Critics quickly blame the exposed problems on the capital-based tourism industry that places too much emphasis on resource development and profit growth. Cave and Dredge [68] claimed that this model has never encouraged tourist destinations to cultivate diversified economic practices to enhance community resilience and regenerative tourism. Before COVID-19, there was only capitalist tourism in the framework, but COVID-19 provides a diverse framework that envisages the coexistence of capitalist, alternative capitalist, and non-capitalist tourism practices, and provides a more resilient and regenerating way for the tourism industry.
As Gallego and Font [67] put forward, the unbalanced global development, antiblackness, white supremacy, and the ideology of exclusion and exceptionalism inherent in tourism activities continue to affect who will get resources, who will get safety, and who will get ecology; that is, who can survive the climatic emergency or the uneven effects of COVID-19.

Distribution by Study Area
Of the 87 articles, only 32 articles (36.78%) conducted specific research on a certain region. Figure 2 shows statistics on these research areas on the map. It can be clearly seen that in these 32 works, China is the most frequently studied region. This result is expected, because China was the first country to have COVID-19 and the impact of COVID-19 on it has been the most profound. This is followed by central Africa and southwestern Europe. Figure 3 specifically shows the frequency of the area being studied. China was selected as the study area with a frequency of 21.88%, ranking first, followed by the Caribbean, Japan, Nigeria, Spain, and Taiwan, which are tied for second with 6.25%. Except for the countries mentioned above, the remaining countries accounted for 3.13%. It can be seen that countries in every continent have conducted different degrees of research on COVID-19 and tourism.

Distribution by Study Area
Of the 87 articles, only 32 articles (36.78%) conducted specific research on a certain region. Figure 2 shows statistics on these research areas on the map. It can be clearly seen that in these 32 works, China is the most frequently studied region. This result is expected, because China was the first country to have COVID-19 and the impact of COVID-19 on it has been the most profound. This is followed by central Africa and southwestern Europe.  Figure 3 specifically shows the frequency of the area being studied. China was selected as the study area with a frequency of 21.88%, ranking first, followed by the Caribbean, Japan, Nigeria, Spain, and Taiwan, which are tied for second with 6.25%. Except for the countries mentioned above, the remaining countries accounted for 3.13%. It can be seen that countries in every continent have conducted different degrees of research on   Table 13 summarizes the theories used in the COVID-19 and tourism literature. COVID-19 is closely related to resilience, so it is not surprising that most literature mentions resilience theory. In addition to resilience theory, other theories that have been repeatedly involved are regenerative economic theory, neoliberal theory, geopolitical theory, and path dependence theory.   Figure 4 shows the proportion of qualitative and quantitative research in the investigated literature. Of the 87 articles, only 16 articles (18.39%) specifically mentioned research methods, and other articles tended to analyze and comment on existing literature or data. Of the 16 articles that mention specific research methods, there are far more qualitative methods than quantitative research methods. It can be seen that scholars are more inclined to use qualitative content analysis, interviews, literature research, and other methods to study COVID-19 and tourism.  Table 13 summarizes the theories used in the COVID-19 and tourism literature. COVID-19 is closely related to resilience, so it is not surprising that most literature mentions resilience theory. In addition to resilience theory, other theories that have been repeatedly involved are regenerative economic theory, neoliberal theory, geopolitical theory, and path dependence theory.  Table 13 summarizes the theories used in the COVID-19 and tourism literature. COVID-19 is closely related to resilience, so it is not surprising that most literature mentions resilience theory. In addition to resilience theory, other theories that have been repeatedly involved are regenerative economic theory, neoliberal theory, geopolitical theory, and path dependence theory. Table 13. Distribution by theory.

Theory Source
Resilience [23,67] Regenerative economy [23,46,68] Neo-liberalism [20,51,67] Liquidity justice [67] Political ecology [55] Geopolitics [12] Path dependence and path creation [55] Compared with mainstream disaster response discourse, the recovery movement provides a completely different vision for post-disaster "reconstruction" and climate "resilience", according to Gallego and Font [67]. Foo et al. [23] pointed out that the flexible adaptation cycle suggests four general stages of change events and concluded that the tourism industry may have begun to enter the stage of innovation and creativity, which is essential for the human system to transform itself to adapt to the new environment of the planet on which it lives.
In the early innovation stage of reorganization, Foo et al. [23] proposed that the most important thing is to be open to all ideas and be willing to make mistakes. Innovation requires us to maintain our judgment and recognize the potential value of each proposition, which means recognizing certain potential values of neoliberal economics and sustainability. Colonial history, neoliberal capitalism, and the continued practice of "attractive" tourism have dramatically increased the vulnerability to climate change, according to Gallego and Font [67].
The COVID-19 pandemic, Ioannides and Gyimóthy [71] claimed, has halted global mobility on an unprecedented scale, severely undermined the neoliberal market mechanism of the world tourism industry, and subsequently led to the decline of certain mainstream business models and the rise of other business models and government interventions. From the review of the recent crisis recovery process, we can see that the tourism industry may rebound from this sudden market shock, mainly because the government actively adopted various forms of intervention measures.
Gallego and Font [67] proposed that the alternative economy of these communitybased organizations requires a complete reconstruction of the economy, labor-management relations, relations with the natural world, and relations with each other. Ateljevic [52] called for a new way of thinking, doing things, and transforming land use and the global food system through regenerative economics. Gallego and Font [67] proposed that sustainable tourism is not only an environmental project or a green business plan but should also be closely linked to mobile justice projects to help support resilient and renewable regional ecosystems economic.
However, the long-term debate on path dependence and path creation questioned this promising future. Brouder et al. [55] argued that after 10 years of growth since the global financial crisis, the number of international tourists exceeded 1.5 billion for the first time in 2019, and the evolution of the tourism industry has shown obvious path dependence. He claimed that only if tourism demand and tourism supply have sufficient institutional innovation to cultivate new paths, tourism transformation can be realized. In this sense, COVID-19 provides a once-in-a-lifetime opportunity to promote transformation at the institutional level, but it remains to be seen whether institutional innovation will cause fundamental changes in the tourism industry [55].
To conclude, Table 14 summarizes the leading themes and perspectives in COVID-19 and tourism and their proportions.
It can be clearly seen from Table 14 that the leading themes and perspectives are ranked as follows:

•
First place: Government crisis management theme (27.59% of the total literature), and "government financial support" is the leading perspective of this theme (50% of the theme). • Second place: Tourist perception and decision-making themes (21.84% of the total literature), and "tourists' perception and decision-making" is the leading perspective of this theme (61.11% of the theme).

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Third place: Travel service providers (19.54% of the total literature), and "fulfill corporate social responsibility" is the leading perspective of this theme (47.06% of the theme). • Fourth place: New normal (13.79% of the total literature), and 50% of scholars have a positive attitude towards the future of tourism.
• Fifth place: Tourism research (12.64% of the total literature), and "the importance of tourism research and education" is the leading perspective of this theme (45.45% of the theme). • Sixth place: Inequality (11.49% of the total literature), and "community inequality in tourism" is the leading perspective of this them (40% of the theme).

Discussion
The preceding text comprehensively reviewed what specifically tourism scholars write about the pandemic and its consequences for tourism. Then, what new insights does the literature on COVID-19 provide to guide our practice in sustainable tourism?

What Are the Challenges We Face?
COVID-19 has induced sustainability challenges in the tourism industry.

Social Sustainability Challenges
The current liberalism and capitalism of the tourism industry has been challenged by the pandemic. Although the tourism industry tries to integrate collectives and communities into the decision-making process, the complexity of the historical and political background of the societies and the system tends to exacerbate the exploitation and inequality in the decision-making process, which leads to more conflicts in the communication and collaboration process, rather than the ideal community inclusive approach. The nature of tourism seems to mirror the nature of institutions and societies. Will companies, citizens, and leaders that promote social responsibility in the crisis really change their actions in the long run so that the needs of the tourism industry are aligned with the needs of the environment and the community? These two arguments suggest that because the tourism industry is based on a capitalist market logic and individualized interests, this essence may still bring tourism back to the old era that excludes communities and the environment. Is a big crisis enough to embed any changes in the global long-term dependent tourism industry or is it a short-lived? As Sheller [51] put it, "the key question is, in the whole story, who are "we"? "Who is the collective? Who is holding the hope of a sustainable future; who respects the sustainable practices promoted by the WTO? And who will lead innovation?" Likewise, Brouder [55] pointed out: "There is a fundamental disconnect between what the United Nations World Tourism Organization promotes (sustainability) and what it practices (growth). Before we can consider the future of tourism, we must first resolve this disconnect".

Environmental Sustainability Challenges
There is no doubt that COVID-19 takes place in a century of crisis. The pandemic is so devastating that people have diverted their attention and investment away from other crises that have happened, are happening, or are about to happen. In the cessation of global tourism (and the cessation of other economic activities) in response to COVID-19, we have witnessed the environmental benefits of reducing tourism, but the environmental release caused by such a reduction in tourism is temporary. As the global tourism industry gradually recovers, the recovery of tourism after the pandemic may restore the previous impact of tourism on communities and the environment. The mitigation of the sustainability crisis is a gradual process that requires unremitting efforts and investment. If other ongoing or upcoming crises have been greatly deprived of attention and resources by COVID-19, these crises may retaliate against mankind in worse ways. Therefore, the environmental challenge induced by COVID-19 lies in the linkage between crises and the setting of priorities, which tests the rapid response of researchers, destinations, enterprises and other stakeholders to the current crisis and the prediction and preparation for the upcoming series of environmental crises. People need to be on their guard because this is going to be a long struggle.

Economical Sustainability Challenges
While academics have confidence in a sustainable future after COVID-19, the cost of maintaining that hope seems immeasurable. We do not yet know what the next crisis will be, it is harder to prepare for it, and at what cost to maintain and convert new systems. It is clear that global stakeholders have paid a high price in response to the huge losses COVID-19 has inflicted on the tourism industry. However, there are other ongoing crises in the world beyond COVID-19 that have distracted academics and funders from research. Will these crises bring a bigger blow to human society in the near future? Some technical difficulties remain, such as a range of metrics.
To summarize, the sustainability challenge of the COVID-19 pandemic comes from the main contradiction deeply rooted in the concept of sustainable tourism itself (i.e., collectivism and individualism, neoliberal policies and protectionism), and comes from the questioning whether the awareness and behavior of stakeholders will be changed for a long time. Table 15 summarizes some of the great challenges in COVID-19 and tourism. These challenges have triggered different attitudes of scholars towards the "new normal", which are derived from the nature of tourism, the nature of institutions, and society.

Challenge Source
Tourism usually focuses on individuals and innovation rather than collective and public transactions. [55] What kind of revolution should be carried out to prevent the fragility of the tourism industry? [27] Not every tourist is interested in change and seeks for change. [66] Preparing for a crisis is difficult and costly, and at what cost should the new system be maintained and converted? [53] How can travel change others? [51] Who is the collective? Who are we? [39] How can change be embedded in the crisis? [27] Are stakeholders in the tourism industry really willing to change or is it a false promise? [48] How to develop a robust index to calibrate the success of human's onerous policy. [49] What about other ongoing crises on the planet? [63] 5.2. What Are We Hoping?
The COVID-19 pandemic has undoubtedly caused great damage, but crises often bring people and communities together. As people's desire for connectivity and sociality is once again manifested, hope will reappear, according to Foo et al. [23]. The halt in economic activity is eye-opening because it gives a glimpse of what the world will be like when too much tourist activity is suppressed. Innovation and entrepreneurship will reveal what is truly feasible and ambitious. COVID-19 has given an unprecedented turning point in the transformation of the world's tourism industry, making everyone look forward to a more sustainable future. Table 16 summarizes the hopes of some scholars involved in COVID-19 and tourism research for the future of tourism.
From the above table, one point needs to be emphasized; that is, most scholars do not expect that COVID-19 will change the nature of the tourism industry, but there is hope for the improvement of the global tourism problems exposed by COVID-19. The tourism industry may rely on capitalist exchanges and provide opportunities for non-capitalist or incomplete capitalist exchanges, but, according to Sheller [51], these forms of exchange also depend on mutual trust and solidarity. These emotions will be needed in the tourism recovery after COVID-19: the belief that people have washed their hands, do not travel when they are sick, and will be taken care of when they are sick. Trust also depends on mutual respect between hosts and guests and the recovery of the government-sponsored tourism market. During the COVID-19 period, hotel owners enthusiastically provided free accommodation services to support medical staff, according to Chen et al. [42]. In addition, the hotel has been used as a designated isolation place to isolate tourists from areas affected by COVID-19 for 14 days of medical observation [69]. Hosts and guests who go hand in hand in adversity are believed to cultivate good relationships. The hotel industry has contributed to the control of COVID-19 and embodies its social responsibility, which is conducive to improving brand image and reputation, thereby promoting the revitalization of the accommodation market after COVID-19 [23]. The hotel will review its corporate social responsibility in order to define new resources and functions [38]. With conscious citizens, consumers, producers, travelers, entrepreneurs, and community leaders calling for and adopting necessary changes, new lifestyles, knowledge, and behaviors are emerging in the world, and they are moving towards a renewable paradigm and a renewable economic system [52]. New way of travel The rise of a travel method that allows fewer entrants but generates more benefits. [50] Host-guest relationship Hosts and guests who go hand in hand in adversity will cultivate a good relationship. [42] Corporate social responsibility Companies will actively assume their social responsibilities. [23] Self-improvement of business and government Companies and governments will learn from COVID-19 and make self-improvements (increasing resilience and creativity) to improve their long-term viability. [38,50] Widespread use of ICT Popularization of digital and intelligent tourism products [3] The well-being of tourists and community residents While limiting economic and social development and unsustainable behaviors in the tourism industry, the focus on a better life actually promotes growth in other areas, such as social and environmental well-being and meaningful interpersonal relationships. [45] Relations between countries Governments will realize the importance of knowledge exchange, cooperation, and joint crisis management [39] Tourism supply chain A tight and more sustainable global tourism supply chain. [21] Companies and governments will learn from COVID-19 and make self-improvements to improve their resilience and creativity, thereby enhancing their long-term viability. In a crisis, governments of various countries will realize the importance of knowledge exchange, cooperation, and joint response to the crisis, and support tourism activities along safe borders. The development of tourism in the pursuit of a better life will continue to maintain the momentum of retreat to achieve sustainable changes in the global tourism industry. While limiting economic and social development and unsustainable behaviors in tourism, the focus on a better life actually promotes growth in other areas, such as social and environmental well-being, and meaningful interpersonal relationships [45]. The good life can reposition the tourism industry as localized tourism and slow tourism, because the good life principle requires these substitutes to be small-scale, local, and help community residents and tourists increase the well-being [45].
The contribution of ICT to communication demonstrated in COVID-19 will make digital and intelligent tourism products popular. These are expected to jointly build a closely cooperative, innovative, flexible, highly elastic, and more sustainable global tourism supply chain.

What Will Be the Turning Point?
The above-mentioned hopes and challenges show that it is not a huge crisis that can make the tourism industry successfully transform, but what people do in the crisis. Then, what exactly is the turning point for a sustainable future?
The turning point will appear in the breakthrough of the nature of tourism, the nature of institutions and society, when people begin to question the value of and advocate for research that is exposing and reflecting on social issues. Changing the belief of ordinary people and reaching a consensus on what sustainable tourism is requires the joint efforts of scholars, educators, leaders, and other stakeholders in the industry. From the lessons of the painful COVID-19, we seem to be able to see the dawn of a promising future, because this pandemic seems to be weeding out the inferior in the industry. However, Stankov et al. [33] questioned that even if civilization progresses, the survival of the fittest will ultimately be difficult to achieve. This makes racial issues within countries and inequalities between countries persist. Establishing measurement indicators to measure social and environmental issues may be an obvious breakthrough. It is also important that we should not neglect other ongoing disasters because of a catastrophe, because in COVID-19, climate change and other man-made crises (such as forest fires, oil spills, and melting glaciers) have already brought surrounding communities' disaster. In this regard, it is vital to set priorities, mark the priorities of the disaster, and set a long-term response plan accordingly.

Conclusions
Due to the global pandemic of COVID-19, the world is facing an unprecedented global health, social, and economic emergency. As of the United Nations Statistics Division (UNSD) dynamic data on January 10, 2021, COVID-19 has caused 90,192,332 cases with 1,936,955 deaths. According to the World Tourism Organization update in December 2020, the confidence index of the World Travel Organization is still at a historically low level due to the slow control of the virus, travel restrictions, and low consumer confidence [1]. First, the tourism industry is highly correlated with people's conscious departure and leisure activity needs [71]. As a result, the impact of the COVID-19 pandemic on the international tourism market is manifested in the health risks and psychological risks perceived by tourists, which leads to negative emotions towards the tourism industry and other tourists. The social distancing imposed by COVID-19 includes activities that reduce social contact and minimize tourism, which greatly affects people's assessment of leisure and travel activities (such as nature-based tourism activities) and personal leisure services (such as spas and catering) [62].The operating standards of COVID-19 force travel service providers to redesign products and services to innovate travel experiences, such as smelling alcohol or disinfected water instead of fragrance and machine services instead of labor [62]. However, without compromising sociality and service quality, how far is the psychological distance between travel service employees and customers? Will the new service environment innovated by travel service providers for COVID-19 change the behavior and attitude of customers?
The drastic reduction in travel demand coupled with the government's travel ban has had a serious impact on the profitability of travel service providers and in turn affected the tourism economy of countries. Given that the international travel ban affects more than 90% of the world's population, as well as extensive restrictions on public gatherings and community movement, tourism basically ceased in March 2020 [50]. Due to people's fear of exposure to public air, strict quarantine measures, and lack of passengers, most domestic and international airlines were forced to cancel flights [62]. Subsequently, the global tourism industry lost millions of jobs due to the cancellation of flights, events, and hotels [62]. The role of the government and the informal sector is emphasized to provide financial and policy support to the affected tourism sector, and to restore domestic regional tourism and market confidence by supporting domestic and tourism, reviving marketing, and intergovernmental cooperation. Through these actions, the government seeks to strike a balance between maintaining the tourism economy and preventing unemployment and poverty, and at the same time responds to public health needs to prevent the collapse of the health system due to tourism [27]. Therefore, it seems unsurprising that government as a leading subject was discovered by this study.
In the second half of 2020, with the gradual reversal of the pandemic and the launch of the COVID-19 vaccine, the World Tourism Organization has proposed a significant increase in passenger confidence and a significant lift in passenger travel restrictions in its update in December 2020 [71]. The rebound is also the result of a large number of pent-up demand months after border closures and travel bans [71]. Faced with the rapid depression of the tourism industry and tourists' aversion to isolation, many countries that are highly dependent on the tourism economy (like Mallorca, Belize, and Cuba) have enacted "safe corridors" plans. In the "safe corridor" system, tourists can freely travel to countries in the safe corridor list without quarantine. However, does this really mean that the impact of COVID-19 is already under control?
Challenges and fears will always exist, due to the high degree of uncertainty in tourism, of whether there will be a new round of pandemic, and our limited understanding of the consequences of actions. The best we can do is to continuously sum up patterns from existing research to try to deal with them, in ways that will never be optimal. This research implies that dealing with the pandemic, like dealing with other sustainability challenges (such as climate warming), will not require exactly the same remedies, but the same kind, building resilience, adaptivity, flexibility, collaboration, and co-creation.
Considering the vast number of publications, increasing in fast pace, it is not easy to get an overview and an understanding of this. Scholars have evaluated the current world tourism industry from various angles and predicted the future of the global tourism industry after COVID-19. However, few researchers have completely integrated the COVID-19 and tourism literature and conducted content analysis to describe a complete framework.
This study filled this research gap by providing a systematic knowledge framework for the intersection of the two emerging research fields of COVID-19 and tourism. In this knowledge framework, this research described specific leading research aspects and discussed the guidance that COVID-19 research has brought to the tourism industry. A literature review of current research on COVID-19 and tourism is vital to piece together a complete answer, highlighting neglected areas of research and pointing out conclusions that have been repeatedly validated and emphasized. This study provided a comprehensive framework for current scholars' perceptions of COVID-19 and tourism and framed the catastrophe of COVID-19 as a long-term sustainable learning opportunity to stimulate different thinking on this popular topic in society and academia.
This literature review of current research indicates some neglected but important research areas to invite future research. From the perspective of enterprise development, the current research focuses on the hotel and aviation industry, but we shall not ignore that the densely populated small and micro enterprises in tourist destinations have also suffered the same impact. What kind of crisis management model should they establish (including corporate resilience, employee management, financial portfolio, and business and management model innovation) and what are the costs and benefits of transformation? For communities, COVID-19 invites us to rethink and update the alternative social system (fairness, cooperation, and social responsibility) in the community and improve the community's adaptability and innovation capabilities. For tourists, stereotypical tourists are usually spoilers and troublemakers, but this research showed that COVID-19 is changing tourists' awareness of ethical tourism and sustainable consumption behavior. Can they travel to change others and how? Moreover, this research emphasizes two urgent aspects.
We urgently need to establish a measurement standard to evaluate the performance of tourism stakeholders and establish a priority to ensure that other crises (such as climate warming, forest fires, species extinctions, etc.) are not ignored when mitigating and responding to the current pandemic. In this century, we seem to be lucky, because we have more technology and experience than ever before, so how should we use new technologies (such as information and communication technology) to create a smart and sustainable tourism future? The challenges of sustainable tourism transformation after COVID-19 are irreversible. How to overcome and mitigate these challenges requires solid empirical research involving various stakeholders, and the voices of residents and marginalized groups ought to always be given priority.