The foundation of human health rests on healthy, stable ecosystems. Our biotic environment provides us with the fundamentals necessary for healthy lives—food, water, oxygen, warmth, light, and fuel. Earth's ecosystems also supply the raw materials for our health-care services. The global fraying of ecosystems has grave implications for our health and our ability to treat illnesses, now and in the future. Although health around the world improved on average over the last half century, it is likely that these gains will be lost if the environmental foundation for health continues to deteriorate
