摘要
Emergy analysis was applied to evaluate Puerto Rico’s sustainability (1960-2013). The sustainability of the system declined 84% during the 54-year period. The largest decline occurred during the 1960s when an agriculture-based economy started to shift to an industrial base of manufacture and service. The trend of moving away from sustainability continued throughout the next four decades when the island became heavily relied on imported fossil fuels, good and services. Policies should decrease the ratio of imported emergy to exported emergy Development strategies should encourage the efficient use of renewable resources based on local production