and voluntary organisations, trade unions, or in Communist times publicly owned enterprises. In May 1959, at the second Congress of Social Tourism in Austria, Walter Hunziker proposed the following definition: "Social tourism is a type of tourism practiced by low-income groups, and which is rendered possible and facilitated by entirely separate and therefore easily recognizable services". Doom tourism Also known as "tourism of doom," or "last chance tourism", this emerging trend involves travelling to places that are environmentally or otherwise threatened (such as the ice caps of Mount Kilimanjaro, the melting glaciers of Patagonia, or the coral of the Great Barrier Reef) before it is too late. Identified by travel trade magazine Travel Age West editor-in-chief Kenneth Shapiro in 2007 and later explored in The New York Times, this type of tourism is believed to be on the rise. Some see the trend as related to sustainable tourism or ecotourism due to the fact that a number of these tourist destinations are considered threatened by environmental factors such as global warming, overpopulation or climate change. Others worry that travel to many of these threatened locations increases an individual's carbon footprint and only hastens problems threatened locations are already facing. Religious tourism Religious tourism, in particular pilgrimage, can serve to strengthen faith and to demonstrate devotion. Religious tourists may seek destinations whose image encourages them to believe that they can strengthen the religious elements of their self-identity in a positive manner. Given this, the perceived image of a destination may be positively influenced by whether it conforms to the requirements of their religious self-identity or not. DNA tourism DNA tourism, also called "ancestry tourism" or "heritage travel", is tourism based on DNA testing. These tourists visit their remote relatives or places where their ancestors came from, or where their relatives reside, based on the results of DNA tests. DNA tourism became a growing trend in 2019. Impacts Growth The World Tourism Organization (UNWTO) forecasts that international tourism will continue growing at the average annual rate of 4%. With the advent of e-commerce, tourism products have become prominent traded items on the internet. Tourism products and services have been made available through intermediaries, although tourism providers (hotels, airlines, etc.), including small-scale operators, can sell their services directly. This has put pressure on intermediaries from both on-line and traditional shops. It has been suggested there is a strong correlation between tourism expenditure per