Uncertainty and the Greenhouse Effect
Robert M. White
Global average temperatures have broken records during the past five years. U.S. farmers in the Midwest have suffered severe droughts. The amount of carbon dioxide in the atmosphere continues to increase. Does all this prove that the ''greenhouse effect'' has begun, bringing us a warmer Earth, rising sea level and a host of unpleasant consequences?
Before you rush to say "yes," consider that the same question might reasonably have been asked after the "Dust Bowl" of the 1930s—years that were followed by a period of cooler global temperatures.
Global warming has become an international scientific and political happening in recent months. Yet how robust is the scientific basis for this outpouring of worldwide concern? Do recent increases in temperature truly signal a permanent trend—or are they just a fluctuation in the perennial cycle of drought and flood?
The situation is not as certain as some headlines would have us believe. Yet, rather than being an excuse to do nothing, this uncertainty challenges us to choose our policies with even greater shrewdness and care.
The concentration of carbon dioxide and greenhouse gases in Earth's atmosphere has increased steadily in this century as a result of the burning of fossil fuels, the production of chlorofluorocarbons (CFCs), worldwide deforestation and other forces. By the middle of the next century, this concentra-
tion is likely to be twice as great as it was at the beginning of the industrial age.
Mathematical computer models of the oceans and atmosphere project that, in response, the planet's temperature will rise at least several degrees Fahrenheit by the middle of the next century. These models are only approximations of the real atmosphere, but their results, while uncertain, must be taken seriously.
The climatic response judged by actual temperature readings from around the world during the past century is less conclusive. Global average temperatures reveal a roller coaster course during the past century with a small net increase of only about 1 degree Fahrenheit. Some temperature records—for example, for the United States—reveal no evidence of change.
Most estimates of the social and economic consequences of global warming are based on scenarios of the future course of climate change and models of economic development. These scenarios can only provide information about the range of possibilities and not predictions of how climate changes will affect agriculture, water resources or ecological systems.
In other words, despite all the headlines, what we have is an inverted pyramid of knowledge, a growing mass of proposals for action balanced upon a handful of real facts.
What policy directions, then, make sense? At the very least, we need to invest immediately in improving the information base. We also should adopt policies that will ease the situation without foreclosing our future options if projections turn out to be incorrect.
Many of these policies involve the production, distribution and end use of energy. We must shift away from coal and oil to natural gas where feasible, increase efficiency in energy production and end uses, and develop passively safe and publicly acceptable nuclear power, as well as other nonfossil energy sources. All such actions will reduce emissions of carbon dioxide.
Energy-policy actions have great leverage because they often help solve other environmental issues, such as acid rain and local air pollution, while reducing our dependence on foreign oil. However, they are inherently controversial because they
imply economic burdens, raising the question of who pays. Any policy framework also must recognize the international nature of the issue and its potential divisiveness between developed and developing nations. Why, for example, should Brazil protect its Amazon forest or China reduce its reliance on coal? To be serious about international action, a global bargain is necessary.
If we cannot arrest the processes of climate change, then we will need to adapt to them. We should think in terms of a continuous policy process where we periodically reassess our responses in light of new findings. Highlighting the uncertainty surrounding climate change in this way runs the risk of being interpreted as a delaying tactic. That would be the worst policy of all. The task before us is to try to step wisely even though our path remains obscured by an uncertain atmosphere.
August 27, 1989
Robert M. White, president of the National Academy of Engineering, was the first administrator of the National Oceanic and Atmospheric Administration.
* * *
Saving Sea Turtles
John J. Magnuson
Long before there were Teenage Mutant Ninja Turtles, our nation's southern coastal waters abounded with the real thing. Sea turtles are among our most distinctive animals. Some grow as big as 1,000 pounds.
These evolutionarily ancient reptiles appeared on earth eons before humans. But now, five species of sea turtles that live in coastal waters of the Atlantic Ocean and the Gulf of Mexico are threatened by human activity—in particular, by shrimp trawls.
The Kemp's ridley turtle faces the most serious danger. As recently as 1947, about 40,000 females came ashore on one day at the species' only nesting beach. Currently, an estimated 350 mature females nest each year at the same Mexican beach along the Gulf of Mexico.
The other four species also are officially threatened or endangered. I chaired a National Research Council committee that has just completed a detailed study of the decline and conservation of these turtles. We concluded that shrimp trawls are killing more sea turtles than all other human activities combined.
Turtles also may be hit by boats, ingest plastic debris, lose their beach habitats, be caught for sport or food, or die in other ways as the result of human activity. But shrimp trawls are responsible for the most deaths, by far. These nets are dragged along the ocean bottom to capture shrimp. The number of turtles caught dead or comatose in the trawls increases dramatically after about 50 minutes of towing because turtles must surface at least once an hour to breathe. Most fishing crews keep their trawls in the water for more than an hour at a time for economic reasons.
The numbers of dead turtles found stranded on beaches increase when shrimp fisheries open in South Carolina and Texas and decrease when a shrimp fishery closes in Texas. Similarly, nesting populations of loggerhead turtles are declining in Georgia and South Carolina, where shrimp fishing is intense. Yet nesting populations are stable or, perhaps, increasing farther down the coast in southeastern Florida, where shrimp fishing is rare or absent.
Previous studies estimated that shrimp trawls kill about 11,000 sea turtles annually. However, after reviewing studies of turtle mortality, counts of stranded carcasses and other evidence, our committee concluded that the actual total may be as much as three or four times higher. A disproportionate number of the animals killed are of prime age to contribute to the breeding populations.
A solution exists to reduce this toll. Turtle excluder devices, or TEDS, can be attached in the nets to allow almost all turtles to escape. TEDs are trap doors that release turtles and other large marine animals from a trawl. Some shrimpers complain that TEDs also allow many shrimp to escape, and their argument has some merit. Although certain TED designs retain almost all of the shrimp under good conditions, performance may suffer from seaweed or debris on the bottom.
Still, the devices are the best method available to conserve populations of the five species—the Kemp's ridley, loggerhead, green, hawksbill and leatherback sea turtles. To conserve these species successfully, TEDs must be used in shrimp trawls at most places from Cape Hatteras to the Mexican border and during most times of the year.
In addition, a greater effort must be made to protect beaches where turtles lay eggs. Many of these critical nesting areas are disturbed by pedestrians, recreational vehicles, sand-cleaning equipment and housing developments. A related problem is artificial light from street lamps and beachside homes; lights can disorient hatchlings during their journey toward the ocean. Several communities have already adopted "lights out" ordinances for the period when turtle eggs are hatching; others should follow their lead. Communities also should consider establishing reserves on important nesting beaches.
"Headstarting" sea turtles by removing eggs from natural nests and hatching the young in captivity for later release is a useful research tool—but it cannot substitute for more essential conservation measures.
Much remains to be learned about the behavior, ecology and physiology of sea turtles. However, their greatest source of danger is now clear—and preventable. The shrimping industry must begin using TEDs routinely, or these timeless creatures will face extinction.
May 27, 1990
John J. Magnuson is a professor of zoology at the University of Wisconsin.
* * *
Who Owns Antarctica?
A few years back, when the U.S. polar research vessel Hero lay at anchor off the Antarctic Peninsula receiving visitors, someone asked the ship's colorful skipper, "Captain Lenie, who owns Antarctica?" The Dutch-born Pieter Lenie hesitated only a moment before replying, "I own it. . . . It belongs to me."
The anecdote, recounted by author Michael Parfit in his book South Light, reflects the proprietary interest in Antarctica felt by those few people privileged to visit, work or even live for a time on the Earth's coldest, driest, most desolate and forbidding continent. It carries also a tinge of the annoyance these people feel toward the interloper.
Antarctica in recent years has become a tourist attraction. Drawn by the same quest for adventure, discovery and personal conquest that inspired the great polar explorers, contemporary adventurers are spending vast sums to cruise to the world's southernmost shores or fly to the South Pole.
Even some of the most vocal proponents of preserving Antarctica as a wildlife refuge have themselves visited the frozen continent and now, as advocates of leaving it alone, seem to want to pull up the drawbridge behind them. I have been to Antarctica as a member of the press and cannot imagine denying another human being access to the range of experiences to be had there: the glare of the six-month summer sun off the polar ice cap, that first eyeball-to-eyeball encounter with a curious Emperor penguin along the ice edge, the wail of a Weddell seal nurturing her pup, the sharpness of the clearest, coldest air on earth. I own Antarctica, too.
The prospect of tourists loose on the perilous Antarctic landscape is a source of dismay for the scientists who have made Antarctica their life's work. Can a continent that spans 5.4 million square miles accommodate both groups?
Science in Antarctica dates back to the earliest explorations and continues to be the cornerstone of cooperation among nations with vastly differing ideologies.
In the last decade, Antarctica has evolved from a land locked in ice and mystery into a living laboratory of global processes. The unfolding story of the ozone "hole," discovered over Antarctica, is an excellent case in point. Observations in Antarctica showed that man-made chemicals—CFCs—cause the depletion of stratospheric ozone, since observed on a smaller scale globally.
Studies of the West Antarctic Ice Sheet reveal the extent of the so-called "greenhouse effect" and resultant global warming, which would raise sea level worldwide. And Antarctica is an observatory, too. The high polar plateau offers a unique vantage point for ground-based observations of the upper atmosphere and beyond.
Government officials who manage American activities in Antarctica are concerned about the safety of visitors, their impact on the fragile antarctic environment and the potential for disruption of the research effort.
Antarctica is a very dangerous place. The wind comes up, sudden and fierce. The clouds descend, and particles of light dance back and forth between them and the ice surface, creating the disorienting condition of "white-out." The ice is lined with deep crevasses.
Yet the antarctic environment is as delicate as it is treacherous. Lacking land predators, the animals are trusting and approachable. But they are not fearless. A horde of humans traipsing through a penguin rookery incites chaos, causing brooding males to abandon eggs and separating chicks from their parents. In the extreme cold and dryness, ordinary litter does not decay.
Tourism detracts from the antarctic scientific enterprise in less subtle ways, too. However unwittingly, private expeditions to Antarctica put themselves in the hands of the governments conducting research there. To rescue people imperiled by weather or an accident requires the diversion of aircraft and crews—at great personal risk—dedicated to the support of science. Visitors wishing to call at research stations and take guided tours interrupt people for whom optimum working conditions exist only a few months each year.
Yet tourists have a right to experience Antarctica, too.
The icy continent beckons, inspires and challenges the human spirit.
However, if we stumble in, heavy-footed and heedless, we risk destroying the essence of its allure. Antarctica commands our attention; it demands our respect.
Thirty-seven nations have chosen to adhere to the Antarctic Treaty and convene regularly to deliberate the fate of Antarctica. The issue of tourism should be at the top of their agenda.
Antarctica belongs to everyone.
October 18, 1988
Hugh Downs is host of the ABC News television program "20/20."
* * *
Genetically Engineered Organisms: Monsters or Miracles?
The first outdoor test of a genetically engineered microorganism took place earlier this year. Gene-altered organisms are being brought out of the laboratory and into the test plot. They are almost ready for the farmer to use.
Such outdoor testing and use is called the "deliberate release" or "planned introduction" of genetically engineered organisms into the environment. The words have something of an ominous sound. Are scientists really making new life forms? Are they dangerous? Will they cause environmental problems?
To address some of these thorny questions, the Council of the National Academy of Sciences convened a special committee of biologists, of which I was a member. Its task was to examine the most frequently voiced concerns about genetically engineered organisms in the light of accumulated
knowledge and experience. The results are summarized in a short publication that has just been released.
First of all, it is important to put recent developments in what is known as recombinant DNA research into historical perspective. Genetic engineering with recombinant DNA is essentially a new approach to an age-old activity, namely breeding. Human beings have been in the breeding business for centuries, producing everything from race horses and hybrid corn to magnificent roses. Breeders don't call themselves genetic engineers, but they do the same sorts of things and have the similar goals of changing organisms in beneficial ways.
Yet the new recombinant DNA techniques are powerful and special because they make it possible to move genes between organisms that don't mate in nature. An insect gene can be put into a plant, for example. But the worry that this will produce new and dangerous life forms can already be answered from experience.
Hundreds of research laboratories around the world have been doing gene transfers for more than a decade. Untold numbers of organisms with foreign genes have been produced and studied—and they have proved to be no more dangerous than their unengineered siblings. An organism is not a dangerous new life form just because it has a new gene from an unrelated organism. In fact, it's much more like one of Burpee's new improved varieties of garden vegetable.
But might these new techniques inadvertently turn an ordinary plant into a superweed that would spread like the kudzu vine that plagues the South? Could recombinant DNA accidentally convert a harmless microbe into a harmful one, like the Dutch elm disease fungus that is killing our magnificent elms?
The answer is that being a weed or a disease-causing organism is very complicated. It takes many genes of just the right kind to be a successful pest. One new gene (or even ten) won't do the job. The bottom line is that these are largely groundless worries. The genetic engineer can't turn corn into kudzu any more than a corn breeder can.
What are the concerns, then? They are the same kinds of concerns that we now have about using organisms. Some organisms, like cabbage and corn plants, aren't much of a
problem at all, and we have plenty of experience in agriculture to guide us. Others require more care, depending on the nature of the organism and how it has been altered.
It is especially important to be cautious in releasing organisms into different ecosystems from those in which they evolved. Experiences with gypsy moths and Japanese beetles, to use familiar examples, have alerted us to what can happen when the interaction between an organism and a new ecosystem is not considered carefully. The scientific community needs to provide guidance in evaluating proposed introductions from an ecological perspective.
And what is the promise of recombinant DNA technology? In my view, the real promise of the new genetic engineering techniques is that they can help us solve some of our most serious problems in better ways than we could before.
To cite just one of many examples, we now kill insect pests with tons of toxic pesticides, inadvertently killing other organisms, disrupting ecosystems and contaminating the soil, our drinking water, even ourselves. Recombinant DNA techniques have begun to show us new and better ways to make pest-free crops. Scientists have recently discovered that genes can be introduced to make plants resistant to certain insects, much as we immunize people against disease.
We are faced with many pressing environmental problems. Recombinant DNA techniques can help us find ecologically sound solutions. But the endeavor is young and vulnerable. We must take care to not stifle it with excessive regulation, just as we must use the genetic engineer's new tools with skill and wisdom.
If we manage to strike a good balance between regulation and innovation, I believe we can look forward to decreasing our reliance on toxic chemicals in both industry and agriculture, and perhaps to cleaning up the world we leave our children. That's miracle enough for me.
August 30, 1987
Nina Fedoroff is a molecular biologist at the Carnegie Institution of Washington.
* * *
Rethinking Radioactive Waste Disposal
Frank L. Parker
Every day the amount of high-level radioactive waste at civilian reactor sites in the United States grows. By the end of this decade, the inventory will produce 1 billion curies of radiation, which is greater than the radiation released by 1,000 tons of radium.
That is a lot of waste, and some of it will remain radioactive for more than 10,000 years—a period longer than all of recorded history. Disposing of the waste safely is one of the most important environmental responsibilities we face. Yet the plan our country has adopted to do so is unrealistic; it fosters acrimony and delay instead of solving the problem.
Current plans are to build a deep geological repository for high-level radioactive waste in Nevada if the site proves acceptable, with the facility opening in the year 2010.
There is a strong worldwide consensus among scientists that this kind of geological isolation is the best and safest long-term option for dealing with the wastes, which now are stored primarily at reactor sites around the country. Yet the U.S. program is unique among those of all nations in its insistence on defining in advance the schedule and technical requirements for every part of the multi-barrier system.
This approach sounds thorough and prudent but actually is a formula for disappointment. Building a waste repository is like creating a mine in which the ''ore'' is put into the ground rather than taken out. Mining is a fundamentally exploratory activity; surprise is part of the underground landscape. No scientist or engineer can anticipate all of the potential problems that might arise as one explores the underground formations. It is like asking Columbus to describe the New World before he's even left Spain.
Nonetheless, given the controversial nature of the project, planners have felt compelled to try to design everything perfectly at the outset, rather than agreeing to make changes as geological features are encountered and scientific understanding develops.
One need not be "pro-nuke" or "anti-nuke" to be concerned about this. Civilian reactors have produced tons of high-level radioactive waste. The alternative to placing these in one or more permanent repositories is to continue storing them at the reactor sites. On-site storage appears to be safe for at least another century, but it may be irresponsible in the long run because of the difficulty in securing, protecting and maintaining so many above-ground sites. Even if every reactor were shut down tomorrow, the wastes would remain.
One possibility might be to move the waste to a repository that would not be closed permanently until further studies are carried out. This would allow the waste to be removed, if necessary, and would still be better than leaving them indefinitely at the reactor sites.
In any case, the United States should stop pursuing an ever-receding mirage of infallibility and adopt a more flexible, experimental policy. This does not mean proceeding recklessly, without regard for future generations. Commercial mining and underground construction both operate on the sound principle of "design (and improve the design) as you go." Canada and Sweden have adopted flexible strategies for disposing of their nuclear waste, and their efforts are much more likely to succeed than ours.
Acting without total certainty is not foolhardy; it is real life. All the facts indicate that it is feasible to place high-level radioactive waste into carefully selected underground facilities where the local geology and ground water conditions ensure isolation of the waste for many millenia, and where waste materials will migrate very slowly if they ever do come into contact with the ground water.
The public should not be placated with absolute guarantees. Most citizens watching the human frailties of their governments and technologists know better. The time has come for Congress, the regulatory agencies and the Department of Energy to adopt a more realistic approach. Continued insistence on a totally predictable system for an unpredictable world assures that our country will encounter delays, rising costs, frustration and a loss of public confidence. It also virtually guarantees that most of the nation's high-level radioactive
wastes will remain where they are rather than being moved to a safer, more permanent repository.
September 2, 1990
Frank L. Parker, professor of environmental engineering at Vanderbilt University in Nashville, chairs the Board on Radioactive Waste Management of the National Research Council.
* * *
Toward a Sustainable Agriculture
One does not have to live on a farm to know that agriculture in the United States faces problems. Many Americans whose closest contact with farming is the neighborhood supermarket worry about pesticide residues in their food, water pollution due to farming, soil erosion, antibiotics in animal products or just the size of their weekly grocery bill.
Many farmers share these concerns, and a growing number of them are interested in experimenting with alternative systems that require lesser amounts of pesticides, fertilizers, antibiotics and fuel. A committee of the National Research Council, on which I served, concluded this week that these systems—often regarded skeptically by many farmers—can be productive and profitable. Farmers around the country with widely varying crops and acreage have discovered that the different methods can be as good for the balance sheet as they are for the environment.
The growing demand for safer food and a cleaner environment suggests the time is ripe for approaches like these to move into the mainstream of American agriculture, just as commercial fertilizers, synthetic pesticides, high-yielding seeds
and improved machinery gained popularity after World War II. This new shift should sustain adequate food supplies well into the next century while improving environmental quality.
The new systems vary but generally emphasize diversification rather than continuous planting of fields to single or only a few crops. Diversified systems tend to be more stable and resilient, offering a hedge against the several disasters that can strike single crops. Diversification also makes it easier for farmers to reduce reliance on external inputs by rotating fields and sequencing crops in ways that enhance soil fertility, control erosion and limit pest populations.
Alternative systems, as contrasted to conventional practices, deliberately take advantage of beneficial interactions that occur naturally among crops, animals, insects and microorganisms. They emphasize management instead of purchased inputs. Computers, advances in biotechnology and other breakthroughs make it possible for farmers to do this with increasing sophistication.
Why, then, do not more farmers use alternate practices? One reason is that the practices require more information, trained labor, time and management skills than do conventional techniques. It also is difficult for farmers to calculate the financial impact of making a change. There are many variables involved, particularly during the transition to some alternative methods. Someone with a family to feed may hesitate before changing.
A dominant reason is that federal agricultural policies provide a powerful deterrent to change for many farmers. Designed in an earlier era, they discourage crop diversity, crop rotations, certain soil conservation practices or reduced applications of pesticides. The chief offender is the federal commodity program, which covers nearly 70 percent of the nation's cropland. It awards subsidies according to the acreage a farmer devotes to a certain crop and yield. A corn farmer who wants to rotate some land to grow alfalfa and increase the fertility of the soil can expect a smaller subsidy.
The program also establishes base yields for farmers according to past production. Farmers strive for the highest base yields—however unrealistic they may be without heavy
use of "off-farm inputs"—or lose potential income. Similarly, the system has encouraged farmers to expand onto marginally productive cropland to increase eligible base acreage. As a result, many farmers manage their farms to maximize subsidies, sometimes at the expense of environmental quality.
Other federal policies also discourage the use of alternatives. Government grading standards require fruits and vegetables to meet stringent cosmetic standards that have little, if any, bearing on nutritional quality. The "perfect" produce at our supermarkets comes at the cost of additional pesticides. Still others make it difficult to replace old pesticides with newer compounds that are safer and more effective. Overall, the current federal system of incentives is outdated.
Certainly, alternative farming is not a panacea. Even with a more favorable commodity support structure, farmers may find it difficult to meet increased management and labor needs and to devise new marketing strategies. More research is needed to identify the best techniques. Yet the potential benefits of alternative agriculture are too bountiful to continue to lie fallow. It is time we discarded outdated policies and practices and replaced them with new ones that are better for farmers, healthier for consumers, safer for the environment—and sustainable.
September 10, 1989
John Pesek is head of the Agronomy Department at Iowa State University, Ames.
* * *
The Paradox of Pesticides
Michael R. Taylor and Charles M. Benbrook
Pesticides are a paradox. They are essential to the agricultural economy, helping make possible the abundant, eco-
nomical food supply Americans value. Yet they are also inherently toxic. Their purpose typically is to kill pests.
This dual nature—conferring benefits but posing risks—justifies the close regulation of pesticides by the Environmental Protection Agency (EPA) and state regulatory agencies. Many feel, however, that EPA's program is not working as well as it might in controlling residues of pesticides in food. In recent surveys consumers named pesticides as their No. 1 food-safety concern.
This concern is probably exaggerated—microbiological contamination of food is very likely a greater public-health threat—but, to its credit, EPA recently announced a plan to address an important part of the pesticide residue problem.
Much of the problem was inherited by EPA when it came into existence in 1970. Many of the pesticides of concern today were introduced in the 1950s and 1960s when testing requirements and safety standards were much less stringent. EPA is also saddled with pesticide laws that are inconsistent and difficult to administer.
In deciding whether a pesticide may be used or how much residue may remain on unprocessed food crops such as fresh tomatoes, EPA is directed by Congress to consider both the risks and benefits of the pesticide's use. When the food crop is processed, however—when the tomatoes become ketchup—EPA usually must drop this balancing approach. For pesticides found to cause cancer in laboratory animals, the law seems to adopt a zero-risk standard, precluding EPA from evaluating scientifically whether residues pose any real risk to human health.
At EPA's request, an expert committee of the National Research Council studied this problem and issued a report and recommendations last year. The committee found that EPA's inconsistent treatment of old and new pesticides was irrational from a scientific and public-health perspective. So, too, are the different standards it now applies to processed and unprocessed foods.
This situation works against the public health. EPA's application of a zero-risk standard for new pesticides in certain processed foods causes farmers to continue using older
pesticides to which this standard has not been applied. Many of these older products are riskier than newer products whose danger is trivial or only theoretical. Yet it is the newer products that remain off the market.
To make the whole process more effective, our committee recommended that EPA apply a negligible-risk standard to old and new pesticides and residues in both processed and unprocessed foods. EPA has accepted such an approach in its new plan, a step that marks real progress toward making the pesticide regulatory system work.
Our analysis showed that the consistent application of a negligible-risk standard by EPA could reduce the potential risk of pesticide residues significantly. The usual benchmark for negligible risk is that a carcinogenic chemical must cause no more than one additional cancer death for every million people exposed to it. These risks are calculated by conservative methods that deliberately overestimate possible risks. In fact, the Food and Drug Administration has concluded that a negligible risk as described here is the functional equivalent of no risk at all.
Fully implementing this standard will also open the door to safer new pesticides and enable EPA to evaluate old ones more rationally. EPA will be able to retain in use those pesticides whose potential risks are insignificant and focus its efforts on reducing or eliminating exposure to pesticides whose potential risks are greater.
To take full advantage of this opportunity, EPA will need to increase the pace of its decision-making on both new and old pesticides and refine the role that benefits play in offsetting greater than negligible risks. EPA's greatest challenge will be dealing with its backlog of older pesticides. This requires a sustained commitment not only from EPA, but also from Congress, which will need to provide additional resources and perhaps new legislation.
Consumers, environmentalists, farmers and pesticide manufacturers all have a stake in the success of our nation's pesticide regulatory program. A successful program protects public health, promotes public confidence in the food supply and provides a more predictable business climate for those
whose livelihood is agriculture. EPA's latest effort, while just a step along the way, is a positive move and deserves support.
November 1, 1988
Michael R. Taylor practices law with King & Spalding in Washington, D.C., and was a member of the National Research Council committee that conducted the 1987 study on pesticide residues. Charles M. Benbrook is executive director of the Research Council's Board on Agriculture.
* * *
Agriculture and Water Quality
Jan van Schilfgaarde
In 1982, ducks and other waterfowl began dying mysteriously at the Kesterson National Wildlife Refuge in central California. Biologists determined that water in the refuge was being contaminated by drainage from irrigated farms. The water contained substantial amounts of selenium, a usually benign trace element that can be deadly in high concentrations. The selenium had leached into the water from farm soil.
Dying birds are a distressing sight. Predictably, the situation caused an outcry in California and throughout the country. Farmers were forbidden to direct any more drainage water into the refuge and a cleanup effort was launched.
Sadly, however, that is not the end of the story for Kesterson, for California's rich San Joaquin Valley, for farmers in many parts of the West or for consumers nationwide. An expert committee of the National Research Council, which I chaired, found recently that similar situations are likely to occur elsewhere. Irrigated agriculture, which has yielded such bounty for the nation's dinner tables and wealth for U.S. farmers, is on a collision course with the environment in many areas.
It is a conflict more severe than most scientists had visualized and one politicians would like to avoid because of the wrenching social and economic choices involved. Yet, if further environmental catastrophes are to be avoided, a new water policy must be crafted that balances environmental, agricultural, and other costs and benefits more effectively than in the past.
Agriculture in the West has been dependent on irrigation for centuries. Today, nearly nine of every ten gallons of water in the region go to irrigate the fruit trees, vegetable fields and other crops destined for America's supermarkets. The price charged for this water often is far below the cost of its development. Current policies, established long ago, encourage farmers to waste water and grow crops on marginal land. Historically, farmers have not had to concern themselves with the environmental cost associated with the disposal of drainage water.
Irrigation agriculture depends for its survival on this disposal. It has long been known that drainage water often is saline, but the problem of disposal tended to be ignored. Now, however, we know drainage water can be deadly to wildlife and potentially to humans, as well. Although selenium was the main concern at Kesterson, other trace elements, such as boron and arsenic, also can be a problem. Like salts, these trace elements are dissolved by the irrigation water. As the water evaporates under the hot Western sun, they become concentrated and more toxic to plants and other organisms. Irrigation drainage also may contain residues of pesticides and fertilizers.
In the past, federal and local policymakers often have addressed drainage problems with temporary fixes rather than with permanent solutions, limiting themselves to options that allow agricultural production to continue unabated. Our committee felt it imperative that the full set of policy alternatives be placed on the table, however contentious they might be to some groups. These options should give appropriate weight to all interests, including environmental ones. Alternatives might include retiring land from agricultural production, raising water prices, and disposing of drainage water in the ocean where physically possible.
Certainly, current federal and state water quality regulations should be expanded to include irrigation drainage. There is no scientific reason why irrigated farmland should not be subject to water quality regulation, as is imposed on manufacturing plants and other types of industries.
Unfortunately, this is not a problem where "win-win" solutions exist to make everyone happy. Nor is it likely to be solved by a single government agency with a limited mission focus; a more multi-faceted approach is necessary. Possible solutions consist of a combination of technical options and changes in how society does business. None of these choices is cheap. All imply a tradeoff of values.
How to resolve these tradeoffs is a question more properly answered by elected officials rather than by a scientific committee like ours. Yet action is necessary if recurrences of Kesterson-like scenarios and potential adverse human-health effects from poor water quality are to be avoided. The national benefit from irrigated agriculture in the West is unquestionably great, but the laws of nature cannot be waived. When agriculture and the environment collide, something has to give.
November 26, 1989
Jan van Schilfgaarde is associate director of the U.S. Agricultural Research Service in Fort Collins, Colo.
* * *
Exploring the Mysteries of 'Deep Ecology'
James D. Nations
There's a movement called "deep ecology" among some environmentalists that could affect one of our planet's most precious and endangered resources: its biological diversity.
The movement is fascinating and noble—but it must be tempered with a more practical view of life on Earth. Here's why:
Plant and animal species in the world's tropical forests are being destroyed at incredible speed, in what some scientists have called an ''extinction spasm.'' From the Amazon to Indonesia, species are being wiped out as their habitats are destroyed by farmers, loggers and others pushing into new territory. This terrible loss is eroding the genetic storehouse that scientists depend upon to develop new foods, medicines and industrial products. Chemicals and crops of the future are being lost forever.
Deep ecology deals with this problem by asserting that human beings have no right to bring other creatures to extinction or to play God by deciding which species serve us and should therefore be allowed to live. It rejects the anthropocentric view that humankind lies at the center of all that is worthwhile, saying instead that all living things—animals, plants, bacteria, viruses—have an equal inherent value.
As a conservationist, I am attracted to the core philosophy of deep ecology. Where I run into trouble with it, however, is in places like rural Central America or on the agricultural frontier in Ecuadorian Amazonia—places where human beings themselves are living on the edge of life. I have never tried to tell a Latin American farmer that he has no right to burn forest for farmland because the trees and wildlife are as inherently valuable as he and his children are. As an anthropologist and a father, I am not prepared to take on that job. You could call this the dilemma of deep ecology meeting the developing world.
When we in the industrial world stop to think about such a seemingly distant problem as this, we must resist the temptation to blame the poor farmers on the scene. The fact is that they generally understand the value of forest and wildlife better than we do in our society of microwave ovens and plastic money. They, not us, gather edible fruit, wild animals for protein, fiber for clothing and ropes, incense for religious ceremonies, natural insecticides, wood for houses, and medicinal plants.
I stayed once in southeastern Mexico with a Mayan farmer
who expressed his view this way: "The outsiders come into our forest and they cut the mahogany and kill the birds and burn everything. I think they hate the forest. But I plant my crops and weed them, and I watch the animals. . . . As for me, I guard the forest."
Today, that Mayan farmer lives in a small remnant of rainforest surrounded by the fields and cattle pastures of 100,000 immigrant colonists. The colonists are fine people who are quick to invite you to share their meager meal. But any of us in the industrial world who want to talk with them about protecting the biological diversity that still surrounds them had better be prepared to explain how it will affect them directly.
If you tell a frontier farmer that he must not clear forest or hunt in a wildlife reserve because this threatens the planet's biological diversity, he will politely perform the cultural equivalent of rolling his eyes and saying "Sure." The same can be said for the government planner in the nation where the pioneer farmer lives.
In other words, deep ecology makes interesting conversation over the seminar table, but it won't fly on the agricultural frontier of the Third World or in the boardrooms of international development banks.
Fortunately, even as advocates speak of deep ecology, many scientists and conservationists are showing a growing pragmatism about the situation. They are recognizing that to obtain the long-term benefits of biological diversity one must focus first—or at least simultaneously—on the immediate, short-term needs of individual people. Few wild gene pools are likely to survive intact in places where people have to struggle simply to provide their basic, daily needs.
This recognition must guide efforts to save the world's tropical forests. People on the frontiers of the developing world must receive material incentives that allow them to prosper by protecting biological diversity rather than by destroying it, and their welfare must be given equal consideration with the welfare of the forests. That done, we can return to the aesthetic arguments of deep ecology with the knowledge
that, when we look up from our discussion, there will still be biological diversity left to experience and enjoy.
August 28, 1988
James D. Nations, director of research at the Center for Human Ecology in Austin, Texas, presented a longer version of this article at a conference on biodiversity sponsored by the Smithsonian Institution and the National Academy of Sciences.
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