There are many different definitions of sustainable tourism that have been developed over the last decade. Most tend to assume that all tourists are responsible for respecting and conserving a location's economic, environmental, and socio-cultural balances.

Global economists forecast continuing international tourism growth, ranging between three and six percent annually, depending on the location. As one of the world's largest and fastest growing industries, this continuous growth will place great stress on remaining biodiverse habitats, often used to support mass tourism. Sustainable tourists are aware of these dangers and seek to protect their favorite destinations, and to protect tourism as an industry. Sustainable tourists face many responsibilities to reduce tourism's impact on communities, including:

• informing themselves of the culture, politics, and economy of the communities being visited.
• anticipating and respecting local cultures' expectations and assumptions.
• contributing to intercultural understanding and tolerance.
• supporting the integrity of local cultures by favoring businesses which conserve cultural heritage
• supporting local economies by purchasing local goods and participating with small, local businesses.
• conserving resources by seeking out businesses that are environmentally conscious, and by using the least possible amount of non-renewable resources.

Ecotourism,according to Heather Robinson (2006) is a subset of sustainable tourism, differing by its focus on ecology. Ecotourism is sustainable tourism that: "contributes actively to the conservation of natural and cultural heritage; includes local and indigenous communities in its planning, development and operation, contributing to their well-being; interprets the natural and cultural heritage of the destination to visitor; and lends itself better to independent travellers, as well as to organized tours for small size groups."^[1]

Large conventions, meetings and other major organized events drive the travel, tourism and hospitality industry. Cities and convention centers compete to attract such commerce, commerce which has heavy impacts on resource use and the environment. Major sporting events, such as the Olympic Games, present special problems regarding environmental burdens and degradation. But burdens imposed by the regular convention industry can be vastly more significant.

Green conventions and events are a new but growing sector and marketing point within the convention and hospitality industry. More environmentally aware organizations, corporations and government agencies are now seeking more sustainable event practices, greener hotels, restaurants and convention venues, and more energy efficient or climate neutral travel and ground transportation.

Additionally, some convention centers have begun to take direct action in reducing the impact of the conventions they host. One example is the Moscone Center in San Francisco, California, which has a very aggressive recycling program, a large solar power system, and other programs aimed at reducing impact and increasing efficiency.

With the advent of the internet, some traditional conventions are being replaced with virtual conventions, where the attendees remain in their home physical location and "attend" the convention by use of a web-based interface programmed for the task. This sort of "virtual" meeting eliminates all of the impacts associated with travel, accommodation, food wastage, and other necessary impacts of traditional, physical conventions.

Travel over long distances requires a large amount of either time or energy. Generally this involves burning fossil fuels, a largely unsustainable practice and one that contributes to climate change, via CO₂ emissions.

Air travel is perhaps the worst offender in this regard, contributing to between 2 and 3% of global carbon emissions ^[2]. Given a business-as-usual approach, this could be expected to rise to 5% by 2015 and 10% by 2050. Car travel is the next worst offender.

Mass transport is the most climate friendly method of travel, and generally the rule is "the bigger the better" - compared to cars, buses are relatively more sustainable, and trains and ships are even more so. Human energy and renewable energy are the most efficient, and hence, sustainable. Travel by bicycle, solar powered car, or sailing boat produces no carbon emissions (although the embodied energy in these vehicles generally comes at the expense of carbon emission).

• The Global Development Research Center
• United Nations Environment Programme
• UN Department of Economic and Social Affairs, Division for Sustainable Development

• International Ecotourism Club
• Free 'Responsible Travel Guidebook' by World Expeditions