Original: Natural capital is described in the book Natural Capitalism as a metaphor for the mineral, plant, and animal formations of the Earth's biosphere when viewed as a means of production of oxygen, water filter, erosion preventer, or provider of other ecosystem services.
Simplified: Natural capital is a metaphor for the mineral, plant, and animal formations of the Earth's biosphere when viewed as a means of production of oxygen, water filter, erosion preventer, or provider of other ecosystem services.