Supplemental Data

Full Text
Environment: Can We Defy Nature's End?
S. L. Pimm, M. Ayres, A. Balmford, G. Branch, K. Brandon, T. Brooks, R. Bustamante, R. Costanza, R. Cowling, L. M. Curran, A. Dobson, S. Farber, G. A. B. da Fonseca, C. Gascon, R. Kitching, J. McNeely, T. Lovejoy, R. A. Mittermeier, N. Myers, J. A. Patz, B. Raffle, D. Rapport, P. Raven, C. Roberts, J. P. Rodríguez, A. B. Rylands, C. Tucker, C. Safina, C. Samper, M. L. J. Stiassny, J. Supriatna, D. H. Wall, D. Wilcove

Supplementary Material

Author Addresses and Points of Contention

Addresses of authors

S. L. Pimm, Center for Environmental Research, MC 5556, Columbia University, New York, NY 10027, USA. M. Ayres, Wildlife Conservation Society, CP 38, Tefé, Amazonas, Brazil. A. Balmford, Conservation Biology Group, Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. G. Branch, Zoology Department, University of Cape Town, Rondebosch 7701, South Africa. K. Brandon, T. Brooks, G. A. B. da Fonseca, C. Gascon, R. A. Mittermeier, A. B. Rylands, Conservation International, 1919 M Street, NW, Suite 600, Washington, DC 20036, USA. R. Bustamante, Tropical and Pelagic Ecosystems Program, CSIRO Marine Research, P.O. Box 120, Cleveland, Queensland 4163, Australia. R. Costanza, Center for Environmental Science, Biology Department and Institute for Ecological Economics, University of Maryland, Box 38, Solomons, MD 20688, USA. R. Cowling, Terrestrial Ecology Research Unit, Department of Botany, University of Port Elizabeth, P.O. Box 1600, Port Elizabeth 6000, South Africa. L. M. Curran, Yale School of Forestry and Environmental Studies, 370 Prospect Street, New Haven, CT 06511 USA. A. Dobson, Department of Ecology and Evolutionary Biology, Princeton University, 211 Eno Hall, Princeton, NJ 08544, USA. S. Farber, Graduate School of Public and International Affairs, University of Pittsburgh, Pittsburgh, PA 15260, USA. R. Kitching, Cooperative Research Center for Tropical Rainforest Ecology and Management, Griffith University, Brisbane 4111, Australia. J. McNeely, World Conservation Union - IUCN, Rue Mauverney 28, 1196 Gland, Switzerland. T. Lovejoy, World Bank, Washington, DC, 20433, USA. N. Myers, Upper Meadow, Old Road, Headington, Oxford, OX3 8SZ, UK. J. A. Patz, Program on Health Effects of Global Environmental Change, Johns Hopkins University, Bloomberg School of Hygiene and Public Health, Baltimore, MD 21205, USA. B. Raffle, Baker Potts, L.L.P., One Shell Plaza, 910 Louisiana, Houston, TX 77002-4995, USA. D. Rapport, School of Rural Planning and Development, College Faculty of Environmental Design and Rural Development, University of Guelph, Guelph, N1G 2W1 and Department of Pharmacology and Toxicology, Faculty of Medicine and Dentistry, The University of Western Ontario, London, Ontario, N6A 5B7 Canada. P. Raven, Missouri Botanical Garden, P.O. Box 299, St. Louis, MO 63166, USA. C. Roberts, Environmental Department, University of York, York, YO10 5DD, UK. J. P. Rodríguez, Centro de Ecología, Instituto Venezolano de Investigaciones Científicas (IVIC), Apartado 21827, Caracas 1020-A, Venezuela. C. Tucker, Laboratory for Terrestrial Physics, Code 923, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA. C. Safina, National Audubon Society, 306 South Bay Ave, Islip, New York, NY 11751, USA. C. Samper, Instituto Alexander von Humboldt, Apartado Aereo 8693, Santafé de Bogotá, Colombia. M. L. J. Stiassny, Department of Ichthyology, Division of Vertebrate Zoology, American Museum of Natural History, Central Park West at 79th St, New York, NY 10024, USA. J. Supriatna, Department of Biology, University of Indonesia, Depok 16424, Indonesia. D. H. Wall, Natural Resource Ecology Laboratory, Colorado State University, Natural and Environmental Science Building, Room B203, Fort Collins, CO 80523, USA. D. Wilcove. Environmental Defense, 1875 Connecticut Ave, NW, Suite 1016, Washington, DC 20009, USA.

Points of Debate

This section is a distillation of comments and concerns of the various authors about the main text, keyed to the specific questions.

Is saving remaining biodiversity still possible?

"Many who destroy biodiversity do so because they are displaced, marginalized, and perceive no alternative. Others do so for short-term profit."

There is much debate about whether it is the world's poor who are the culprits or large, rich companies, or the politically well-connected. All contribute. At issue here is whether at the global scale we must destroy biodiversity to survive. We argue we do not--at least for the present. The emphasis in this section is on the world's poor. We save the rich for later in the paper.

Will protecting areas work?

"Even when available, some may view foreign purchase of conservation concessions as imperialism in a 21st century guise. Almost all the hotspots were European colonies; one is still French territory."

These sentences provoked strong dissent with some viewing them as essential and others preferring not to include them. They remain because to hide them would miss the implication. Conservation is a local matter, one involving national sovereignty, and the willingness to help or finance conservation efforts from outside a country is fraught with difficulties. This makes the need for in-country training--and the centers where it will take place--even more crucial.

Should efforts concentrate on protection or on slowing harm?

"Most of us agree that immediate protection of ecosystems and training of in-country professionals is vital. Nonetheless, some effort should be allocated to actions to lighten the burden on future generations of conservation professionals."

There are many facets to this complex issue. For example, are efforts better invested in slowing population growth in a conservation priority area, developing the good will of the people who surround it, or in rigorously excluding them from a protected area? How one should manage parks and the areas that surround them is just one small part of that problem, but it is one that has already generated considerable debate in the pages of Science. For instance:

R. E. Sinclair, D. Ludwig, C. W. Clark, Science 289, 1875 (2000); letters in response: D. Western, K. Benirschke et al. and P. H. Raven, Science 280, 1507 (1998).

[Note: The following section has been corrected since original posting (details of corrections).]

An Estimate of the Cost of Conservation

Aaron Bruner, Richard E. Rice, and Gustavo A. B. da Fonseca

Center for Applied Biodiversity Science, Conservation International, 1919 M Street, NW, Suite 600, Washington, DC 20036, USA.

5 July 2000

The costs of conservation vary widely across the tropics, depending on factors such as the value of alternative resource uses, human pressure, and the cost of conservation activities. Setting aside and protecting land in remote parts of the Amazon Basin is far less expensive than doing the same in dipterocarp forests in Indonesia or heavily populated areas in West Africa. Because of both costs and the difficulty of protecting some places, conserving all valuable areas is simply not possible. If we cannot protect everything, then what is a reasonable goal, and what will it cost?

Roughly 80% of the world's species live in the 4.8% of the earth's land surface that makes up the hotspots and tropical wilderness areas. If we can protect one-third of the remaining wilderness areas (perhaps 200 million hectares), we believe we can preserve an estimated 70% of wilderness area diversity. Additionally, if we can protect one-third of the unprotected hotspots (perhaps 40 million hectares), together with existing protected areas, we believe we can preserve an estimated 90% of total hotspot biodiversity. The combined protection of these hotspot and wilderness areas could therefore ensure protection of perhaps 70% of total global biodiversity on roughly 2% of earth's land surface.

The cost? In the wilderness areas, we estimate that total costs (acquisition and management) will generally range from US$10 to $35 per hectare. For instance, The Nature Conservancy and Conservation International each recently bought out logging concessions in Bolivia at a cost of approximately $2.50 per hectare (1, 2). Land in several other parts of the Amazon is currently for sale at between $2 and $10 per hectare (3). Land values in the Congo Basin may be somewhat higher. Assuming that we achieve our goal of 200 million hectares by protecting an equal percentage of the remaining area of each of the three major wilderness areas, we estimate an average acquisition cost of $7 per hectare. Estimated management costs range from perhaps $0.25 to $2.00 per year [authors' calculations from unpublished data; (4)]. Again, assuming protection of an equal percentage of remaining area of each of the wilderness areas, we estimate an average annual management cost of $0.60. At a real annual return of 5%, establishing a trust fund to meet this need in perpetuity would require $12 per hectare. As an extrapolation based on limited data about both land acquisition costs and long-term management costs, we therefore estimate total cost per hectare for the wilderness areas at $19.

For the hotspots, cost estimates are even more varied. Nonetheless, similar extrapolations suggest an average one-time cost of $265 per hectare (calculations based on 11 hotspots with each hotspot weighted according to the size of one-third of remaining unprotected area). This cost is composed of an estimated $210 per hectare for acquisition, and $55 per hectare in a management trust fund ($2.75 per hectare per year). Again, these estimates are broad extrapolations from limited data. As noted, the range of costs is wide. Costs to set aside land range from perhaps $40 per hectare in Central America (5) and Chile, to perhaps $240 in Fiji and up to $1000 in parts of Brazil's Atlantic Forest. The net present value of unlogged forest in Cambodia may be as high as $1,700 per hectare (6). Annual management costs may range from approximately $1 per hectare for parks in parts of Tanzania and Uganda (7) and under $3 in Mexico (4), up to perhaps $7 in parts of Southeast Asia (4). However, it is also important to note that even in relatively expensive regions, management is not universally expensive. A recent estimate for a large forest park in Southeast Asia placed annual management costs at approximately $1 per hectare.

Using these costs, protection of one-third of the wilderness areas (200 million hectares at $19 per hectare) would cost $3.8 billion. Protection of one-third of the unprotected hotspots (40 million hectares at $265 per hectare) would cost $10.6 billion. Improving management of existing protected areas in the hotspots might cost an additional $4 billion. We therefore cautiously estimate the total cost of protecting 70% of global biodiversity at $19 billion above current expenditures.

References and Notes

1. R. E. Gullison, R. E. Rice, A. G. Blundell, Nature 404, 923 (2000).

2. J. Peterson, The Nature Conservancy Bolivia and partners sign agreement on climate change project: corporations invest in forest protection, potential carbon emission credits (unpublished fact sheet, 3 March 1998).

3. Conservation International, The Central Suriname Nature Reserve (Conservation International, Washington, DC, 1999).

4. A. N. James, M. J. B. Green, J. R. Paine, Global Review of Protected Area Budgets and Staff (World Conservation Monitoring Center, Cambridge, UK, 1999).

5. D. Tobias, R. Mendelsohn, Ambio 20, 91 (1991).

6. C. Bann, "An economic assessment of tropical forest land use options, Ratanakiri Province, Cambodia" (EEPSEA Research Report Series, Economy and Environment Program for Southeast Asia, Singapore, 1997).

7. T. T. Struhsaker, Africa's Rainforest Protected Areas: Problems and Possible Solutions (Report submitted to the Center for Applied Biodiversity Science at Conservation International, 6 June 2001).

Further Discussion of Conservation Costs

In response, Andrew Balmford writes:

James et al. (4) suggest a total figure of $300 billion annually for a conservation system ensuring both representation and persistence of all of the planet's species and ecosystem processes. However, at least 90% of this cost covers "greening the wider landscape," especially in the agricultural sector; less than 10% of the $300 billion per year is needed for reserves. James et al.'s estimate of the cost of establishment of new protected areas and adequate management for existing reserves, across the entire of Latin America and the Caribbean, Developing Asia, Sub-Saharan Africa, and the Pacific, totals ~$7 billion plus ~$4 billion annually. If the annual cost was covered by payments from a trust fund, this would imply a total cost of a reserve network covering ~15% of the tropics of ~$50 billion. Hotspots cover a tiny--but biologically crucial and relatively expensive--portion of this area. Wilderness areas cover a larger, but less developed and therefore cheaper fraction. Thus, given the paucity of data on this issue, calculations from the James et al. (4) database of the cost of these remarkable conservation bargains are in striking concordance with the bottom-up estimates extrapolated from case studies in the Amazonian wilderness area (1) and the Cape Fynbos hotspot (8).

References and Notes

8. R. M. Cowling, R. L. Pressey, A. T. Lombard, C. E. Heijnis, D. M. Richardson, N. Cole, Framework for a conservation plan for the Cape Floristic Region (Institute for Plant Conservation, Cape Town, South Africa, 1999); available at

To protect marine biodiversity, Rodrigo Bustamante writes:

Three key aspects of the text's estimate of $2.5 billion remain hidden.

First, the overall value for biodiversity investment given would apply only in developing countries. As in land, these happen to host most of marine biodiversity and are still in better state that the ones in developed countries, affording greater opportunities for conservation. Marine protected areas (MPAs) in developed countries as in the EU or USA, will demand much higher levels of investments as compared with ones for Ecuador or Indonesia, for example.

Second, some of the costs involve "complementary actions" to biodiversity research, e.g., education, enforcement, and mitigation. The costs do not intend to educate all stakeholders or to reconvert or buy-off all fishing from a given area. With relatively few resources, we will not eliminate all local small-scale artesenal fisheries or achieve sustainable marine exploitation.

Third, I have recently reviewed my empirical example of marine biodiversity conservation, the Marine Reserve of the Galapagos Islands, with the Charles Darwin Research Station as the biodiversity research center. An upper figure of about $3.5 million per year is used for marine and terrestrial research and education requires about $3.5 million per year; the park authority spends $2.5 million per year for marine enforcing and patrolling. This brings the overall investment per protected area at: $6 million per year � 40 reserves � 10 years to a total of ~$2.5 billion.

In short, an estimate $2.5 billion investment will be required for the next 10 years to create a pilot network of 40 new, fully protected marine reserves in identified developing countries, each with their corresponding biodiversity research centers and complementary actions (for example, communication and education to support conservation and enforcing; reconverting a fraction of fishermen to nonextractive alternatives; and limited and selective buy-off schemes for small-scale fleet and fishing rights). These areas will be chosen by identifying key marine regions and biomes and setting aside ~20% of their defined extent. If achieved, this will bring up a few orders of magnitude the current extent of marine areas under full protection. (Today it is <1%.)

Note on Corrections

In the section of this supplemental data now titled "An Estimate of the Costs of Conservation," the authors requested a number of changes before the publication date that were inadvertantly excluded in the production process from the published supplemental data. Those changes have been incorporated into the corrected version that appears above. Briefly, the substantive changes (apart from correction of minor typographical errors) include the following:

  • Title: The title of the section was changed from "A 'Back of the Envelope' Estimate of the Costs of Conservation" to "An Estimate of the Costs of Conservation."
  • Seventh sentence of paragraph three: The words "authors' calculations from unpublished data" originally read "authors' calculations from (4)." Reference (4) in the original, to a 1998 Bolivian government document, has been deleted, and subsequent references have been renumbered accordingly (see below).
  • Fifth sentence of paragraph four: The phrase that currently reads "Costs to set aside land range from perhaps $40 per hectare in Central America" originally read "Costs to set aside land range from perhaps $7 per hectare in parts of Madagascar [authors' calculations from (6)] and $40 per hectare in Central America." Reference (6) in the original, to a 1997 study by Kramer and Sharma, has been deleted, and subsequent references have been renumbered accordingly (see below).
  • Seventh sentence of paragraph four: The phrase that currently reads "Annual management costs may range from $0.50 per hectare to $3 per hectare in parts of east, central, and west Africa" originally read "Annual management costs may range from approximately $1 per hectare for parks in parts of Tanzania and Uganda." The reference accompanying the original phrase, to a 1996 report by Struhsaker, was changed to a 2001 report by Struhsaker (see below).
  • Final sentence: The words "above current expenditures" have been added to the last sentence of the section's text.
  • Changes to references: The following changes have been made to the references for this section:
    • Reference 4 in the original has been deleted in the current version. The original reference was Ministerio de Desarrollo Sostenible y Medio Ambiente y Fundacion Amigos de la Naturaleza, Parque Nacional Noel Kempff Mercado: Informe Anual de Actividades 1998 (Santa Cruz, Bolivia, 1998).
    • Reference 5 in the original has been renumbered to reference 4 in the current version.
    • Reference 6 in the original has been deleted in the current version. The original reference was R. A. Kramer, N. Sharma, in R. A. Kramer et al., Eds., Last Stand. (Oxford Univ. Press, New York, 1997).
    • References 7 and 8 in the original have been renumbered to references 5 and 6 in the current version.
    • Reference 9 in the original version has been renumbered to reference 7 in the current version, and has been updated to a 2001 version of the referenced report. The original reference was T. T. Struhsaker, Conservation of Africa's forest parks: An action plan for long-term support and monitoring (unpublished report, 1996).
    • Reference 10 in the following section in the original has been renumbered to reference 8 in the current version.

We regret the errors in the originally posted version.