Even though it might sound similar, it is necessary to differentiate between the two of them.
The management of sustainable tourism focuses on the management of a type of tourism, from the preconceived idea that ecotourism, naturalistic tourism or sustainable tourism is a subsector of tourism. For some authors, it is a type of tourism that is intended for all those people attracted to know the natural resources in particular of a destination.
For others, it was identified as alternative tourism and several subtypes were exposed: from the rural, whose main motivation is to know and sometimes carry out the customs and traditions of man in the rural world; to ornithological tourism. The common denominator of all of them is that they are a type of tourism that seeks to get away from mass tourism, or at least, it tended to be understood that way at that time.
On the other hand, the sustainable management of tourism is based on premises of sustainable commitment to the ecological, socio-cultural and economic spheres, with the support of the government ir public administration. In short, it is governed by vertices of sustainability regardless of the specific kind of tourism on which the activity is based and applied in a general way to all areas and types that tourism encompasses.
It is necessary to take this last premise into consideration, as well as to differentiate between both concepts, in order to apply development strategies in the tourism field under a prism that does an apology (as in praise, defense and justification) to sustainability and that does not break the ideal barriers of balance in any of the vertices previously mentioned.
What about the externalities?
Externalities, as a concept, appear when dealing with the sustainable management of tourism. They are factors that have been excluded from the traditional economic balance, but tend to be included from the point of view of environmental economics. Thus, making the competitiveness of destinations vary according to the impact on natural resources that are produced in the place; starting from the premise that the landscape and the natural environment of these places are its main attraction.
These factors always include those variables that affect the environment and that can be caused both by the residents of the place and by the tourist activity that takes place there.
For that reason, at a micro or local level, we could speak of the destruction of wild habitats. This is the case of Hawaii, as explained in the publication Negative Impact of Tourism on Hawaii Natives and Environment, where the great development of hotels (among other tourist infrastructures) from 1985 to 2010 has multiplied the number of rooms from 65,000 to 132,000. With the consequent absorption of spaces and resources, which were previously for local use and enjoyment, as well as of other natural spaces.
The consumption and waste of the five (there have been years that up to seven) million tourists who annually visit the Hawaiian Islands and also the energy resources that are needed for them, directly affect the environment. For these reasons, it has been reported that 60% of the plants and species in Hawaii are considered in danger of extinction.
Another example would be the fragmentation of society linked to the creation of tourist ghettos, as in the specific case of Angkor Wat in Cambodia some years ago. The saturation of tourists (both backpackers and “honeymooners”) creates such a “non-local” atmosphere in the place that certain visitors with their actions tend to insult the local population, as well as their culture and religion. An article in The Guardian clearly exposes the local rejection due to an unorthodox initiative that spreaded among some social groups of visitors who go to the temples: undressing and taking photos to publish them.
On the other hand, while tourism has already been overcrowded and encompassed by large tour operators and foreign investment, the vast majority of locals that during the "boom" did not have the sufficient means to benefit from tourism have remained in the same situation of poverty. In nearby cities such as the well-known Siam Reap, prices have skyrocketed and the clear evidence between the upper and lower social classes has been even more marked, practically bypassing the middle class. Facts from my visit there.
This creates a rejection of tourism on the part of the locals, which subsequently negatively affects the value of the place for the tourist, since they may feel rejected due to the generalization on the part of the local population.
At a macro level, the consumption of fossil fuels acts negatively and directly on the greenhouse effect due to the composition of these fuels. This applies to tourism in terms of travel by plane, among others.