According to the World Tourism Organization, sustainable tourism is “Tourism that takes full account of its current and future economic, social and environmental impacts, addressing the needs of visitors, the industry, the environment, and host communities"
Thus, sustainable tourism should:
1) Make optimal use of environmental resources that constitute a key element in tourism development, maintaining essential ecological processes and helping to conserve natural heritage and biodiversity.
2) Respect the socio-cultural authenticity of host communities, conserve their built and living cultural heritage and traditional values, and contribute to inter-cultural understanding and tolerance.
3) Ensure viable, long-term economic operations, providing socio-economic benefits to all stakeholders that are fairly distributed, including stable employment and income-earning opportunities and social services to host communities, and contributing to poverty alleviation.
Sustainable tourism development requires the informed participation of all relevant stakeholders, as well as strong political leadership to ensure wide participation and consensus building. Achieving sustainable tourism is a continuous process and it requires constant monitoring of impacts, introducing the necessary preventive and/or corrective measures whenever necessary.
Sustainable tourism should also maintain a high level of tourist satisfaction and ensure a meaningful experience to the tourists, raising their awareness about sustainability issues and promoting sustainable tourism practices amongst them.
The twelve main goals for sustainable tourism laid out in 2005 by the World Tourism Organization and the United Nations Environment Program are as follows:
 Making Tourism More Sustainable - A Guide for Policy Makers, UNEP and UNWTO, 2005, p.11-12 http://www.unep.fr/shared/publications/pdf/DTIx0592xPA-TourismPolicyEN.pdf
Except the term sustainable tourism there are two other types of tourism that are also focused on creating a tourism in harmony with environment and social-cultural aspects:
On one hand, tourism wields tremendous economic positive outcomes: it is one of the world’s most significant sources of economic outcomes and employment. However, tourism is a very complex industry involving numerous stakeholders (sometimes with opposite interests) and requiring significant amount of resources. As such, tourism can have very opposite effects according to the way activities are managed. Managed well, tourism can play a positive role in the socio, cultural, economical, environmental and political development of the destination and as such represents a significant development opportunity for many countries and communities. On the contrary, unchecked tourism development can lead to very damageable impacts impacts on natural resources, consumption patterns, pollution and social systems. The need for sustainable planning and management is imperative for the industry to survive as a whole.
The quality of the environment, both natural and man-made, is essential to tourism. However, tourism's relationship with the environment is complex. It involves many activities that can have adverse environmental effects. Many of these impacts are linked with the construction of general infrastructure such as roads and airports, and of tourism facilities, including resorts, hotels, restaurants, shops, golf courses and marinas. The negative impacts of tourism development can gradually destroy the environmental resources on which it depends.
On the other hand, tourism has the potential to create beneficial effects on the environment by contributing to environmental protection and conservation. It is a way to raise awareness of environmental values and it can serve as a tool to finance protection of natural areas and increase their economic importance.
Tourism development can put enormous pressure on an area and lead to impacts such as soil erosion, increased pollution, discharges into the sea, natural habitat loss, increased pressure on endangered species and heightened vulnerability to forest fires. It often puts a strain on water resources, and it can force local populations to compete for the use of critical resources.
The socio-cultural impacts of tourism described here are the effects on host communities of direct and indirect relations with tourists, and of interaction with the tourism industry. For a variety of reasons, host communities often are the weaker party in interactions with their guests and service providers, leveraging any influence they might have. These influences are not always apparent, as they are difficult to measure, depend on value judgments and are often indirect or hard to identify.
The impacts arise when tourism brings about changes in value systems and behaviour and thereby threatens indigenous identity. Furthermore, changes often occur in community structure, family relationships, collective traditional life styles, ceremonies and morality. But tourism can also generate positive impacts as it can serve as a supportive force for peace, foster pride in cultural traditions and help avoid urban relocation by creating local jobs. As often happens when different cultures meet, socio-cultural impacts are ambiguous: the same objectively described impacts are seen as beneficial by some groups, and are perceived as negative - or as having negative aspects - by other stakeholders.
Economic Impacts of Tourism
The tourism industry generates substantial economic benefits to both host countries and tourists' home countries. Especially in developing countries, one of the primary motivations for a region to promote itself as a tourism destination is the expected economic improvement.
As with other impacts, this massive economic development brings along both positive and negative consequences.
While sustainable tourism has many positive goals, there must be a concrete measurement system that enables the business to determine their progress towards sustainability. In order to measure results and progress, benchmarks are used. Benchmarking is “the comparison of a business’s performance in a given area (such as water consumption) with those of a similar business.” Benchmarking does not only put a business’s activities in perspective with that of its competitors, but also contributes to many positive internal improvements.
For example, in tourism sector, commonly used benchmarks are:
With these benchmarking categories, achieving sustainability in the tourism industry is not just a rhetorical goal; it is tangible, providing measurable benefits and potential economic savings to those businesses who strive for improvement in their daily performance.
By beginning to benchmark activities, businesses can engage in sustainable development while simultaneously reaping the tangible and economic benefits of internal improvements.
Environmentally sustainable practices
 Travel & Tourism ECONOMIC IMPACT 2016 EUROPEAN UNION LCU