In what respects is "natural capital" similar to human-made capital, and in what respects does it differ? We often speak of a "return to capital," meaning the stream of income generated by a capital investment. Can we speak of a return to natural capital? What are examples of investment in natural capital? Who is motivated to make such investments? Who would suffer if such investments were not made, or if "disinvestment" occurs due to resource depletion or environmental degradation?