Sustainability, ecosystem services, and health

Sustainable development without regular delivery of sen ices from the ecological component of Earth's life support system is presently impossible. Dependable delivery of these services over large temporal and spatial spans requires healthy ecosystems with unimpaired integrity. However, the conditions required for sustainable use of the planet's ecological life support systems have not received the attention necessary. Ecological resources as commodities (e.g. fisheries, timber) have received some attention, but those services (e.g. atmospheric gas balance) perceived as beneficial to human society have not. For example, we neither know how many can be eliminated and still serve as a life support system nor how much fragmentation will impair adequate delivery of services. The purpose of this manuscript is to initiate a discussion on these topics.