Tourism has been proposed as an important tool for

sustainable development, yet decision-makers lack

appropriate measures for its economic, social, and

environmental success. "Sustainable tourism" implies a

finite limit to tourism growth beyond which point it

is no longer sustainable, yet to date, benchmark

environmental indicators have not been developed to

define a destination's carrying capacity. This

dissertation utilizes concepts from ecological

economics towards defining a sustainable scale for

tourism development. In addition, an ecological

footprint indicator (EF) is applied to two populations

(residents and tourists) responsible for both local

and global environmental pressures. These

distinctions are important because traditional

concepts of tourism carrying capacity focus solely on

impacts to the host destination. This creates the

possibility that tourism activity viewed as locally

sustainable is still causing impacts elsewhere on the

planet. By widening the scale of the ecological

footprint, I quantify and discuss the differences

between local and global environmental pressures of

tourism.

Proponents of "alternative tourism" (agrotourism,

ecotourism, bicycle tourism) have suggested the Merse

watershed in Tuscany Italy be developed to absorb

tourist overflow from crowded city centers. My

findings are that combined local activity of host and

visitor populations does not exceed (in terms of

ecological footprint) the biocapacity calculated for

Val di Merse. However, biocapacity for Val di Merse is

exceeded when arrival transport to the destination is

included, with tourist equivalent resident EF rising

from 5.36 to 38.15 gha/person. I conclude that tourism

frequently is declared locally sustainable without

examination of its impacts at a global level. In

response, I propose an alternative conceptual model

which provides a foundation for knowledge management

across multiple spatial scales. Local policy

strategies for tourism are explored using conceptual

models, analysis of eco-efficiency, and the

area's tradeoffs in greenhouse gas emission inventory.