Putting a Price Tag on the Planet

How much are ecosystems worth to humans? More than you might think.

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Chart: The value of ecosystems in selected countries

Article: 4 Ecosystem Choices, for Better or Worse

Forum: Join an online discussion about the Millennium Ecosystem Assessment, a vast study that measured ecosystems' benefits to human beings, and its implications for environmental protection.

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By LILA GUTERMAN

As the 20th century drew to a close, leaders in the field of ecology decided they were failing at one of their primary goals. They had presented sign after sign that people were harming the environment — killing off species, destroying rain forests, polluting the air and water — but the warnings had little effect. So, to encourage conservation, they decided to appeal to humanity's baser instincts.

More than 1,300 scientists and social scientists spent four years on a project that shows people exactly what the environment does for them.

Called the Millennium Ecosystem Assessment, the enormous project looks at whether those benefits, dubbed ecosystem services, have strengthened or weakened in the past 50 years. And the report peers into the future, forecasting whether the services will continue to sustain human life. In another 50 years, will the planet provide enough food, wood, water for its inhabitants?

"Making that link between ecosystems and humans was really crucial. It's an anthropocentric viewpoint," says Harold A. Mooney, a professor of biological sciences at Stanford University and co-chair of the panel that ran the study. "It has much more meaning to many more people."

The assessment found a major incongruity: While ecosystems have suffered more damage in the past 50 years than in any other 50 years in history, people are now healthier, more secure, and freer than ever before. But because those gains in well-being have come at increasing costs to the environment, the ecologists predict that the natural world will one day be incapable of providing the resources people need. Already, people suffer in pockets of the globe as the desert encroaches, droughts strike, and floods overwhelm.

"If you look at the total picture, it gives you a sense of real warning," says Mr. Mooney. "We can't go on like this."

Robert J. Scholes, a scientist at the Council for Scientific and Industrial Research, a government organization in Pretoria, South Africa, who led one of the project's major efforts, agrees but adds that the assessment "isn't a 'the end of the world is nigh' kind of message. It's saying there's a whole bunch of serious problems, but we think it's within the world's technical and political capacity to actually do something about this."

It may be too early to decide whether the study will significantly affect policy. The assessment team published its comprehensive findings in January in four volumes, called Ecosystems and Human Well-Being (Island Press). But the work has left dozens, perhaps hundreds, of scientists with new ideas about their own research, and about the give and take between human beings and ecosystems.

Another Assessment

Though the ecologists came up with the idea of looking at how ecosystems support human life, they borrowed the idea for a global assessment from another group of scientists.

Since 1988 climate researchers from around the world have come together regularly to assess the state of the planet's climate and whether human beings are causing global temperatures to climb. Hundreds of experts have compiled results from thousands of studies under the moniker of the Intergovernmental Panel on Climate Change, which the United Nations sponsors.

By the group's third report, in 2001, the scientists had reached consensus: People had significantly changed the climate, and they would, unless they changed their ways, continue to raise global temperatures, melt glaciers, and raise the level of the seas. Although the reports have proved largely unsuccessful in changing the direction of U.S. policy, they have persuaded many national and international organizations to focus on global warming.

With that in mind, the ecology researchers circulated their proposal to assess ecosystems among international organizations, national governments, conservation groups, and local communities.

"If this was to succeed," says Walter V. Reid, the assessment's director and a consulting professor at Stanford's Woods Institute for the Environment, "it had to be something the users asked for."

They did. In 2000 three international conservation-treaty organizations, the Convention on Biological Diversity, the Ramsar Convention on Wetlands, and the Convention to Combat Desertification, formally requested the assessment. The same year, Kofi Annan, secretary general of the United Nations, called for it in a report to the U.N. General Assembly.

Mr. Reid and others raised $17-million for the assessment from the United Nations, the World Bank, the David and Lucile Packard Foundation, the governments of China, Norway, and Saudi Arabia, and many other governmental and nongovernmental groups.

During the project's first year, in 2001, a group of senior scientists decided the assessment should focus on human well-being and on the benefits provided by ecosystems. The scientists identified 24 ecosystem services, which include such obvious resources as food, fresh water, and fuel.

But ecosystems also play less visible roles like controlling disease and creating soil. And the scientists also decided that ecosystems feed the soul, by providing recreation, beauty, and spiritual meaning. The assessment would examine how human beings had affected those services and how people had benefited from ecosystems, by analyzing the results of existing studies. It would then translate that analysis into language useful for policy makers.

Discouraging Data

Mr. Scholes's group had perhaps the most depressing job — assessing how ecosystems fare now and how they have changed over the past 50 years. It reports that a great majority of plants and vertebrates are declining in distribution, in abundance, or in both. Ten percent to 30 percent of mammals, birds, and amphibians face extinction.

People converted more wild land to cropland in the 30 years after 1950 than in the 150 years beginning in 1700. In the second half of the 20th century, 20 percent of the world's coral reefs and 35 percent of the mangroves were destroyed.

In contrast, human beings are faring better than ever. The world population doubled between 1960 and 2000, while food production increased by a factor of two and a half. As a result, food prices have gone down and fewer people go hungry.

But bad news lurks even in the good: The gains in well-being have often been purchased at the environment's expense, the scientists concluded. The assessment, says Peter Kareiva, a scientist at the Nature Conservancy who worked on the report, was "first to explicitly admit that countries have profited enormously from destroying wild ecosystems."

What's more, the poor have often borne the brunt of declining ecosystems.

Half of the world's population works in agriculture, the sector most closely tied to ecosystem services. Already, weakened ecosystems have provided less fresh water or failed to control floods in many instances, causing people a great deal of hardship, according to the report. The numbers of floods and fires, for instance, have both increased significantly in the past 50 years, at least partly because of ecosystem changes.

Human beings have depleted one-quarter of the world's fisheries and are harvesting another one-half at their maximum capacity. The recent collapse of the Atlantic cod stocks could prophesy similar problems elsewhere: After hundreds of years of cod fishing off the east coast of Newfoundland, the fishery closed in 1992 when stocks suddenly fell to extremely low levels. Other abrupt changes may come as assaults continue on ecosystems, the scientists warn.

The scientists found that in the past 50 years, people have degraded 15 services, or 60 percent of the 24 benefits that ecosystems provide humanity, including supplying fresh water, breaking down air pollutants, and preventing erosion. Only four have been enhanced, including crop and livestock production.

People often recognize only the ecosystem values, such as food, crops, and timber, that are bought and sold — a prime reason, many scientists think, that people treat unseen ecosystem services, like flood protection, so cavalierly. The assessors use a number of ways to estimate the prices of less-tangible services, including calculating the cost of replacing the value lost when people, say, clear a forest.

The ecologists cite a study of the forests in eight countries around the Mediterranean Sea that used such methods to find that a forest's total economic value was, on average, more than three times greater than the value of the wood used for burning and building. The rest of the forest's value came from less-visible services it provided, such as protecting freshwater supplies (see map, Page A25).

Mr. Scholes says the assessment's results should ring a warning bell. At a daylong symposium on the millennium assessment at the Ecological Society of America's meeting last August in Montreal, he said that although "prophets of doom have been with us for millennia," two important changes had taken place recently.

The first, he said, is that "there is not a square centimeter of the earth" that people haven't perturbed. The second is that people can no longer plead ignorance of the consequences of that influence.

Future Imperfect

Those consequences are not certain, but using various data and computer programs that simulate environmental trends, scientists on the assessment team came up with four scenarios, or stories about possible directions for the next 50 years. The scenarios illustrate what several global-scale trends and policies would do to the environment, and each comes with its own pluses and minuses (see sidebar, Page A26).

"We very deliberately did not have a business-as-usual scenario," says Stephen R. Carpenter, a professor of zoology at the University of Wisconsin at Madison, who led the scenarios working group with Prabhu L. Pingali, an economist at the Food and Agriculture Organization of the United Nations, in Rome.

One scenario envisions a world dominated by national-security concerns in which leaders solve ecological problems only after they cause a crisis. Another depicts widespread cooperation among nations to create and use technology to keep ecosystems healthy.

Mr. Carpenter argues that no one scenario is the best. "The scenarios should be viewed as a menu of options," he says. One might work well in some circumstances — for instance, the security-related scenario could be strongest for protecting countries from bird flu — while others might protect ecosystems better in different circumstances, and countries could even pursue different strategies in turn.

Given the uncertainty about the future, the assessment leaders tapped another team of researchers to look at how well some 70 possible actions protect ecosystems.

Some of the most effective responses, such as creating protected areas, regulating pollutants, and educating people about the environment, are well known and already occur in many places around the world.

Other existing efforts are too limited to make a significant difference globally. The Costa Rican government, for example, has for a decade paid landowners to keep their forests intact or to reforest developed areas. China's "Grain for Green" program is similar: It pays farmers to stop planting crops on steep slopes, which caused flooding by increasing runoff.

The actions that would have the greatest impact would require big changes, including major investments by governments in green technology, aggressive attempts to eliminate poverty, and efforts to deal with environmental concerns before they become problems. The millennium assessment's synthesis report sums up: "The changes required are large and are not currently under way."

Effects on Policy Makers

"I'll be curious in 50 years looking back," says Elena M. Bennett, an assistant professor in the department of natural-resource sciences at McGill University who participated in the assessment, "to see, Did we as a society heed the warning and start to take some big actions?"

So far the assessment has had modest but numerous effects on policy makers. In the Philippines, for instance, a competitiveness plan for the country's agriculture sector is based on the assessment's concepts of ecosystem services. South Africa has incorporated findings from the assessment into a national biodiversity strategy.

Stephen Bass, a senior fellow at the International Institute for Environment and Development, a nongovernmental policy-research group in London, thinks the assessment's all-encompassing nature may hurt its chances of affecting policy. "The millennium assessment seemed to ask about 150 questions in multiple areas and hasn't really made a big impact," he says.

Mr. Reid, the assessment's director, acknowledges that the most important changes will probably come locally rather than globally. So he is heartened that the Chinese, French, and Mexican governments are planning or have begun assessments of their own ecosystems. "There are very few decisions at a global scale that have an effect on ecosystems," he says. "We'd need a country or region to do this kind of assessment and analysis linked to their own decision-making processes. Having this happen in a country the size of China is enormously exciting."

The multinational treaty organizations that requested the assessment, including the Convention on Biological Diversity and the Ramsar Convention on Wetlands, are already using the core ideas about ecosystem services to make long-term plans, says Mr. Reid.

But the arena that the assessment may influence most strongly is one it had not focused on reaching. "What is surprising," reflects Mr. Reid, "is the extent to which it's used by the research community."

Study participants interviewed by The Chronicle say that their involvement has greatly informed the way they think about their research, and sometimes even their research topics or methods. Ms. Bennett, who was a postdoctoral fellow in Mr. Carpenter's laboratory and helped run the scenarios group, says that because of the assessment, her future studies of the effects of phosphorous in fresh water will look at social systems, as well as ecological ones. "It's clearer to me now how big the impact is of people and communities," she says.

The millennium-assessment scientists also hope that other researchers will pitch in to fill hundreds of gaps in the data or to create new research tools that the assessors had wished they had, such as ways to predict when abrupt changes are imminent, better computer-simulation models for playing out scenarios, and better ways to quantify the value of nonmarket ecosystem services. The International Council for Science, a group of national science bodies including the United States' National Academy of Sciences, has encouraged its members to perform research that will fill those holes.

The 1,300 researchers who worked on the study, and the 850 who served as peer reviewers, have begun to document what they learned and how it has affected their work. "We've started to see the millennium assessment appearing more and more in the scientific literature," says Mr. Carpenter. "This will have an impact on the scientific culture."

How much it affects either science or policy may depend upon whether or not scientists perform another global assessment. "It's crucial that it happen again," says Mr. Mooney. Without new assessments, he says, "we can't see if we've gotten better or worse."

ECOSYSTEMS: MORE THAN MEETS THE WALLET Ecosystems provide value for human beings in more ways than can be tallied in the marketplace. The scientists of the Millennium Ecosystem Assessment cite a study showing that eight countries around the Mediterranean Sea, have overlooked two-thirds of the forests' total value because it doesn't fit in traditional markets. Commonly measured values of forest services, including timber and fuel wood Nonmarket values of forest services, including watershed protection and recreation: Total economic value: Dollars per hectare Algeria 45 22 Croatia 132 100 Italy 88 165 Morocco 49 16 Portugal 157 187 Syria 3 86 Tunisia 82 63 Turkey 33 12 SOURCE: Millennium Ecosystem Assessment