Emergy synthesis, sustainability of environment and economy of Macao

The metabolism of a city can be seen as a process of transforming all the materials and commodities for sustaining the city's economic activity. This paper attempts to incorporate the analysis of emergy and material flow for investigating Macao's urban sustainability in the light of Macao's environment and economy. In order to evaluate the contribution of material flows to the ecological economic system, emergy (spelled with an M; previously known as embodied emergy) evaluation is incorporated in this paper. Emergy evaluation of urban metabolism is analyzed for measuring the effect of Macao's sustainability. The purchased emergy from outside Macao is 160 x 10(20) sej in 2003, while the output emergy is about 196 x 10(20) sej. Tourism is the biggest industry of Macao, it bring 5.82 billion US dollars to Macao economy, the en/dollar emery equals to 119.7 x 10(20) sej, it is the most important source to sustain the balance of the urban emergy flows. With the analysis of the tourism in Macao and its contribution to Macao urban development, a new indicator (the ratio of tourism emery contributions to emery impact) is proposed. Through use of the indicators of the emery, the sustainability of Macao is discussed.