A quick tour through an average U.S. hospital gives pause to anyone with even a rudimentary concern for environmental issues. To a careful observer, the typical U.S. hospital presents an array of challenges to the health of ecosystems. For example, hospitals consume vast quantities of natural resources. The most obvious of these are fossil fuels, which form the basic building blocks of the industrialized medical care industry. Aside from the worry that our healthcare systems are technologically and functionally dependent upon nonrenewable, relatively scarce, and politically volatile resources, our heavy reliance on fossil fuels has important ill effects, including unfavorable health outcomes for humans. For example, the combustion of fossil fuels is the driving force behind global warming, which will likely result in increasing heat-related mortality and morbidity and may contribute to the spread and resurgence of infectious diseases around the world. Also, the combustion of coal and oil releases pollutants such as sulfur oxides, nitrogen oxides, and ground-level ozone that contribute to various respiratory ailments. In addition to being energy intensive, the modern hospital uses a great deal of water, wood, paper, metals, minerals, plastics, chemicals, food, and land.