The Value of the World's Ecosystem Services and Natural Capital by Robert Costanza1, Ralph d'Arge2, Rudolf de Groot3, Stephen Farber4, Monica Grasso5, Bruce Hannon6, Karin Limburg7, Shahid Naeem8, Robert V. O'Neill9, Jose Paruelo10, Robert G. Raskin11, Paul Sutton12, & Marjan van den Belt13 Published in NATURE Vol. 387, 15 May 1987 (p 253-260) 1. Center for Environmental and Estuarine Studies, Zoology Dept., and Institute for Ecological Economics, University of Maryland, Box 38, Solomons, MD 20688, USA 2. Economics Department (emeritus), University of Wyoming, Laramie, WY, 82070, USA 3. Center for Environment and Climate Studies, Wageningen Agricultural University, PO Box 9101, 6700 HB Wageningen, The Netherlands 4. Graduate School of Public and International Affairs, University of Pittsburgh, Pittsburgh, PA 15260, USA 5. University of Maryland Institute for Ecological Economics, Box 38, Solomons, MD 20688, USA 6. Geography Department and NCSA, University of Illinois, Urbana, IL 61801, USA 7. Institute of Ecosystem Studies, Millbrook, NY, USA (current address: Department of Systems Ecology, University of Stockholm, S-106 91 Stockholm, Sweden) 8. Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN 55108, USA 9. Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA 10. Department of Ecology, Faculty of Agronomy, University of Buenos Aires, Av. San Martin 4453, 1417 Buenos Aires, Argentina 11. Jet Propulsion Laboratory, Pasadena, CA 91109, USA 12. National Center for Geographic Information and Analysis, Department of Geography, University of California at Santa Barbara, Santa Barbara CA 93106, USA 13. Ecological Economics Research and Applications, Inc., PO Box 1589, Solomons, MD 20688, USA

1 We estimated the current economic value of 17 ecosystem services for 16 biomes, based on a synthesis of published studies and a few original calculations. For the entire biosphere, the value (most of which is outside the market) is estimated to be in the range of $16 - 54 trillion/yr., with an average of $33 trillion/yr. Because of the nature of the uncertainties, this must be considered a minimum estimate. Global GNP is around $18 trillion/yr. The services of ecological systems and the natural capital stocks that produce them are critical to the functioning of the earth's life support system. They contribute significantly to human welfare, both directly and indirectly, and therefore represent a significant portion of the total economic value of the planet. Because these services are not fully captured in markets or adequately quantified in terms comparable with economic services and manufactured capital, they are often given too little weight in policy decisions. This neglect may ultimately compromise the sustainability of humans in the biosphere. The economies of the earth would grind to a halt without the services of ecological life support systems, so in one sense their total value to the economy is infinite. However, it is instructive to estimate the "incremental" or "marginal" value of ecosystem services - the estimated rate of change of value with changes in ecosystem services from their current levels. There have been many studies in the last few decades aimed at estimating the value of a wide variety of ecosystem services. We synthesized this large (but scattered) literature and present it in a form useful for ecologists, economists, policy makers, and the general public. From this synthesis, we estimated values for ecosystem services per unit area by biome, and then multiplied by the total area of each biome and summed over all services and biomes. While acknowledging the many conceptual and empirical problems inherent in producing such an estimate, we think this exercise is essential in order to (1) make the range of potential values of the services of ecosystems more apparent (2) establish at least a first approximation of the relative magnitude of global ecosystem services (3) set up a framework for their further

2 analysis (4) point out those areas most in need of additional research and (5) stimulate additional research and debate. Most of the problems and uncertainties we encountered indicate that our estimate represents a minimum value, which would probably increase: (1) with additional effort in studying and valuing a broader range of ecosystem services (2) with the incorporation of more realistic representations of ecosystem dynamics and interdependence and (3) as ecosystem services become more stressed and "scarce" in the future. Ecosystem Functions and Ecosystem Services Ecosystem functions refer variously to the habitat, biological, or systems properties or processes of ecosystems. Ecosystem goods (e.g. food) and services (e.g. waste assimilation) represent the benefits human populations derive, directly or indirectly, from ecosystem functions. For simplicity, we will refer to ecosystem goods and services together as ecosystem services. A large number of functions and services can be identified.1-4 Daily5 provides a detailed recent compendium on describing, measuring, and valuing ecosystem services. For the purposes of this analysis we grouped ecosystem services into 17 major categories. These groups are listed in Table 1. We included only renewable ecosystem services, excluding non-renewable fuels and minerals and the atmosphere. Note that ecosystem services and functions do not necessarily show a one-to-one correspondence. In some cases a single ecosystem service is the product of two or more ecosystem functions whereas in other cases a single ecosystem function contributes to two or more ecosystem services. It is also important to emphasize the interdependent nature of many ecosystem functions. For example, some of the net primary production in an ecosystem ends up as food, the consumption of which generates respiratory products necessary for primary production. Even though these functions and services are interdependent, in many cases they can be added because they represent "joint products" of the ecosystem which support human welfare. To the extent possible, we have attempted to distinguish joint and addable products from products which would represent "double counting" (because they represent different aspects of the same service) if they were added. It is also important to recognize that a minimum level of