Stilwell, Diogo Campos de CarvalhoAbreu, António Domingos2014-07-222014-07-2220121647-1989http://hdl.handle.net/10437/5361Tourism was considered for a long time, a non-polluting industry, the so-called “industry without chimneys”. However, as the world’s population increased and technological developments allowed for more frequent travel, tourism grew and began to generate significant impacts, whether social, environmental or economic. Sustainability is therefore a key factor in current and future tourism development and rather than an abstract concept, it must be measurable. Considering that sustainable tourism is a truly unrealistic objective for the foreseeable future, a more realistic target would be monitoring the performance of tourism and its trends through sustainability indicators. Although difficult to define, indicators assume a priority role as instruments. Even considering that they are uncertain and imperfect models of the reality and are made of compromises among various factors such as relevance or scientific validity, they are still robust tools that promote sustainability. Due to the current crisis, the Portuguese tourism sector is having an increasing importance in the economic development.application/pdfengopenAccessopenAccessopenAccessTURISMOTOURISMTURISMO SUSTENTÁVELSUSTAINABLE TOURISMINDÚSTRIA TURÍSTICATOURISM INDUSTRYarticle