International tourism

International tourism is tourism that crosses national borders. Globalisation has made tourism a popular global leisure activity. The World Tourism Organization defines tourists as people "traveling to and staying in places outside their usual environment for not more than one consecutive year for leisure, business and other purposes". The World Health Organization (WHO) estimates that up to 500,000 people are in flight at any one time.

In 2010, international tourism reached US$919B, growing 6.5% over 2009, corresponding to an increase in real terms of 4.7%. In 2010, there were over 940 million international tourist arrivals worldwide. By 2016 that number had risen to 1,235 million, producing 1,220 billion USD in destination spending. The COVID-19 crisis had significant negative effects on international tourism significantly slowing the overall increasing trend.

International tourism has significant impacts on the environment, exacerbated in part by the problems created by air travel but also by other issues, including wealthy tourists bringing lifestyles that stress local infrastructure, water and trash systems among others.

History
As a result of the late-2000s recession, international travel demand suffered a strong slowdown from the second half of 2008 through the end of 2009. This negative trend intensified during 2009, exacerbated in some countries due to the outbreak of the H1N1 influenza virus, resulting in a worldwide decline of 4.2% in 2009 to 880 million international tourists arrivals, and a 5.7% decline in international tourism receipts.

COVID-19
Some people have taken advantage of airlines drastically reducing their fares to travel for leisure despite multiple warnings to remain at home, along with two-week self-quarantine requirements upon arrival or return from travel. A number of college students tested positive for COVID-19 after returning from traditional spring break destinations such as the Florida beaches, South Padre Island, and Cabo San Lucas. Many tourism venues such as museums, visitor centers, restaurants and hotels mandated COVID-19 vaccination for their staff or visitors. Research has shown that tourists have varying levels of belief on COVID-19 vaccination in terms of its effectiveness and side effects, which have impact on the preferences of tourists to preference to visit or use "vaccinated venues".

Together with a decreased willingness to travel, the restrictions have had a negative economic impact on the travel sector in those regions. A possible long-term impact has been a decline of business travel and international conferencing, and the rise of their virtual, online equivalents. Concerns have been raised over the effectiveness of travel restrictions to contain the spread of COVID-19.

In Cambodia, Foreign arrivals in March 2020 fell by 65% year-on-year. Angkor Wat, usually crowded with thousands of tourists per day, was left almost deserted, with an average of 22 ticket sales per day for the whole Angkor National Park during April 2020. In Vietnam, Foreign arrivals in April 2020 fell by 98% year-on-year.

Tourism in Hawaii went on hiatus. Tourist arrivals in Hawaii down nearly 100% in April 2020 and its 14-day mandatory quarantine kept tourism low. A number of tourists who came to the state but did not follow the quarantine were arrested. In June 2020, Hawaii had still not set a date for reopening to out-of-state tourism. As of 16 June, the quarantine would be lifted for inter-island tourism. Florida tourism had a year-over-year 11% drop in the first quarter of 2020. During the pandemic in Door County, Wisconsin, hundreds of seasonal residents relocated to the county earlier in the spring than they typically do. In 2020, staycations became popular in the United States, where most people spent their vacation time at or close to home. Most vacation travel was done by car, as gas prices are low and many people prefer to wait to the last minute to plan trips due to uncertainties. There were sharp declines in travel by air, cruise ship, bus and rail.

In Australia, Tourism bodies have suggested that the total economic cost to the sector, as of 11 February 2020, would be A$4.5 billion. Casino earnings are expected to fall. At least two localities in Australia, Cairns and the Gold Coast, have reported already lost earnings of more than $600 million. The Australian Tourism Industry Council (ATIC) called on the Government of Australia for financial support especially in light of the large number of small businesses affected. In March, national travel agency Flight Centre has indefinitely closed 100 stores throughout Australia, due to significantly lower demand for travel. It also suffered a 75% decline in share price, and announced that 6,000 staff would be made redundant or placed on unpaid leave globally.

Total volume of cross-border tourist travel
International tourist arrivals reached 1.035 billion in 2012, up from over 996 million in 2011, and 952 million in 2010. In 2011 and 2012, international travel demand continued to recover from the losses resulting from the late-2000s recession, where tourism suffered a strong slowdown from the second half of 2008 through the end of 2009. After a 5% increase in the first half of 2008, growth in international tourist arrivals moved into negative territory in the second half of 2008, and ended up only 2% for the year, compared to a 7% increase in 2007. The negative trend intensified during 2009, exacerbated in some countries due to the outbreak of the H1N1 influenza virus, resulting in a worldwide decline of 4.2% in 2009 to 880 million international tourists arrivals, and a 5.7% decline in international tourism receipts.

World's top tourism destinations
In 2019, there were 1.460 billion international tourist arrivals worldwide, with a growth of 3.7% as compared to 2018. The World Tourism Organization reports the following ten destinations as the most visited in terms of the number of international travelers in 2019.

International tourism receipts
The World Tourism Organization reports that international tourism receipts were US$1.7 trillion in 2018, an increase in real terms of 4% over 2017. The top ten tourism earners in 2018 were:

International tourism expenditure
The World Tourism Organization reports the following countries as the ten biggest spenders on international tourism for the year 2018.

Euromonitor International Top City Destinations Ranking
Euromonitor International rated these the world's most visited cities by international tourists in 2017: