'Gloom and doom' reports about the world environment appear regularly. Just as regularly, the sense of urgency they generate dissipates, and the point-of-no-return deadlines they set prove to be premature.
But the challenges they identify remain to be addressed and to be dealt with.
This article is the fifth in a series written in conjunction with the Foreign Policy Association's 'Great Decisions '82' program.
In this era of Reaganomics - with the United States federal budget emphasizing military buildup over social or environmental concerns - who remembers ''The Global 2000 Report to the President''?
Released with much fanfare on July 24, 1980, by the Carter administration, it was billed as the most comprehensive assessment yet made of what some scientists believe to be humanity's march toward ecological disaster.
It was, in fact, the official US government version of the many ''limits to growth'' studies that made similar dire prophecies in the 1970s. As such, it was intended to be the basis for a new foreign policy initiative in which the United States would lead the world out of environmental danger through a combination of precept, example, and judiciously targeted foreign aid.
US representatives announced this intention in foreign capitals. Ambassadors from a number of nations were briefed on the ''Global 2000'' findings in Washington. The new foreign-policy initiative was to have been inaugurated with a global summit meeting early last year.
The Reagan administration, which takes a less messianic view of foreign aid, has quietly ignored all of this. The Carter call to action seems to have faded from public consciousness as well.
Yet the challenge raised by ''Global 2000'' remains. The world does appear to be heading toward various kinds of environmental decay. These still need to be dealt with both on a national and a global level.
The report tried to convey a sense of urgency by pointing out the possible consequences of these trends by AD 2000:
* World population will grow from 4 billion in 1980 to 6.35 billion in 2000, with the poorest countries accounting for 90 percent of the increase.
* While food production will rise, it is the more-developed nations that will benefit.
* The amount of farmable land will decline on a per capita basis - an expected 4 percent increase in acreage being more than offset by population growth and loss of land to erosion, desertification, salting, or waterlogging.
* As much as 20 percent of existing plant and animal species will become extinct.
* The need for water will have doubled in almost half the world, while water supplies remained inadequate.
* Forests, already severely depleted in many countries, will lose a further 40 percent of their acreage globally. At the same time, commercial timber supplies will fall by 50 percent. Available firewood will meet only 80 percent of world need. (Firewood shortage already is a major problem in parts of Asia and Africa.)
* Signs of climatic change due to atmospheric carbon dioxide may have become evident.
Such a list does, indeed, point up a need to husband the world's resources. But the ''Global 2000'' report may not have been the best vehicle for presenting this challenge. As both its authors and its critics admit, its message was hardly new. It could be expected to have little impact without the new foreign policy that President Carter thought would follow from it.
Moreover, the document was assembled from the memorandums of many government agencies over three years. (Mr. Carter had asked for a one-year study.) Critics claim that, as a result, some of its findings rest on outdated or faulty data, a point even its authors grant.
Its tone has been criticized as unduly pessimistic. For instance, the report warns that ''if present trends continue, the world in 2000 will be more crowded, more polluted, less stable ecologically, and more vulnerable to disruption than the world we live in now.''
''What a big 'if' that is,'' said the late ecologist Rene Dubos, responding to what he called the report's ''hysterical statements.'' He added that ''wherever human beings are concerned, trend is never destiny.''
Such criticism does not imply that the trends identified are unimportant or that they can safely be ignored. What is questioned is the implication that the world is rapidly heading for disaster and is fast running out of time to avert it.
''Prompt and vigorous changes in public policy around the world are needed, . . .'' Global 2000 said. It added, ''If decisions are delayed until the problems become worse, options for effective action will be severely reduced.'' This sounds remarkably like ''gloom and doom'' statements fashionable 15 years ago that have turned out to be grossly exaggerated.
For example, in 1969 United Nations Secretary-General U Thant said: ''I can only conclude from the information that is available to me . . . that the members of the United Nations have perhaps 10 years left in which to subordinate their ancient quarrels and launch a global partnership to curb the arms race, to improve the human environment, to defuse the population explosion, and to supply the required momentum to development efforts. If such a global partnership is not forged within the next decade, then I very much fear that the (environmental) problems I have mentioned will have reached such staggering proportions that they will be beyond our capacity to control.''
That deadline is past, and no one seriously suggests the world has passed a point of no return. Critics have objected to this same kind of hyperbole in the Global 2000 report.
''The report's authors acknowledge that adequate information does not exist for evaluating the future. . . . They simply asserted that the future will be catastrophic unless we change our ways rapidly and drastically,'' says Dr. Dubos.
British ecologist Lord Ashby of Brandon, who has long been critical of the apocalyptic approach to environmental and resource challenges, has outlined what he considers a more fruitful course. He explains:
''A wise assumption would be that social attitudes cannot change except incrementally, and that there are 'tolerable limits,' so to speak, to the magnitude of a change which people will contemplate and accept. . . . All attempts to define goals for mankind are likely to be mirages, vanishing as one approaches them. ''There is another way. . . . That is not to demand a grandiloquent metamorphosis of mankind, but instead to encourage little groups of people all over the place to make wise choices over small changes in society. . . . Men and women do respond to messages which lie within their range of understanding, but mankind is deaf to all messages.''One of the most important of environmental problems - population growth - illustrates Lord Ashby's point.China, which was encouraging a one-child-per-couple movement, now has a more ambitious program aimed at eventual population reduction. It would halt population growth by 2000. Over the following eight decades, it would gradually reduce population, then stabilize it at some 650 million to 700 million. This is a formidable undertaking, considering that so far only about 10 percent of couples capable of bearing children have adopted the one-child policy.In Latin America, where population is doubling every 25 years, Mexico has become the first nation to implement a policy of limited growth. Its goal is to bring the growth rate down from the 3.5 percent rate of the early 1970s to 2.5 percent this year, with the hope of cutting it to 1 percent by 2000.India's experience has shown that attaining such goals may not be easy. After extensive efforts at birth control, census reports last year indicated the country is nowhere near being on track toward its official goal of stabilizing population by the century's end.According to Nancy Robinson, an urban planner at the Colegio de Mexico's Center for Economic and Demographic Studies, India's birth-control program failed because it lacked cultural appeal. In contrast, Mexico's National Population Council has prepared materials it deems appropriate for Mexico's own rural areas. Miss Robinson adds that the 1980 Mexican census provided a sign that the program is working. The Mexican population was 67.4 million in contrast with the 71.9 million predicted by early 1970 trends.Such action by individual countries is showing up in global statistics. United Nations projections reported last year indicate world population growth is slowing. But it could take 130 years for growth to halt. By then, the world could have 10.5 billion people. As the UN report noted, this is no ground for complacency. For many decades, population growth will put increasing pressure on resources. But there also is no ground for despair.The carbon dioxide-climate problem is another example of a serious environmental concern that cannot be dealt with by drastic action now. Carbon dioxide is released when fossil fuels or wood is burned. Some is taken up by growing plants. Some is absorbed by the oceans. However, some of the gas is accumulating in the atmosphere, where it traps heat radiating upward from Earth's surface.Atmospheric monitoring shows a gradual warming is under way. Theoretical studies indicate that, over the next century or so, this warming could change climate. The Antarctic ice cap could melt, flooding many coastal lands and cities. The Arctic sea ice could disappear. Recently Prof. Hermann Flohn of the University of Bonn suggested the Arctic sea ice could melt relatively quickly, even before the Antarctic ice did. The resulting climate change could bring semiarid conditions to parts of Europe and make a desert of American Midwestern wheat lands.If one were reasonably certain such a danger does exist, it would be wise to restrict use of coal. But the forecast is uncertain. Basic scientific knowledge needed to assess the problem is incomplete. Meteorologist John Griffiths of Texas A&M University explains, ''We don't have very much information yet on the magnitude of such a change, so I wonder if we can assess it finely enough to predict exactly what will happen.''Thus it is too early to call for sharp restrictions on growth in use of coal - a course that would require agreement among China, the United States, and the Soviet Union, the main coal-using countries. What is needed is a better grasp of the potential for danger. Research to gain this is under way around the world.Studies such as Global 2000 center on computerized modeling. Complex sets of mathematical equations represent economic, demographic, and other trends and their interactions. These mathematical models allow analysts to study complicated problems, such as the possible consequences of economic and environmental trends.However, the models necessarily neglect many factors, such as human motivations and inventiveness. Their forecasts depend heavily on assumptions the modelers build into their equations. Thus, while such studies can be powerful aids, they are no crystal ball for predicting the future - as one of the most famous of the modelers, Dennis Meadows, has often pointed out.With his wife, Dana, Dr. Meadows led the original study of the global environment and resource challenge using these techniques. Called ''Limits to Growth,'' it was issued a decade ago.Barry Richmond, an associate at Dartmouth College's Resource Policy Center and a colleague of Dr. Meadows, has explained the role of such studies by saying: ''. . . the value of systems approaches to analysis is that it forces one to think clearly, to try to establish the relevant factors involved in various policies. There are few 'answers' in setting up flow charts, establishing rates and levels of activity, and running the programs through a computer. The key is the process, not the results.''Studies such as Global 2000 alert people to environmental dangers whose trends and causes are too intricate and subtle to be easily comprehended. They can be a reason for intelligent concern. But they are no basis for launching global crusades to bring drastic changes in humanity's diverse cultures. Nor can they reliably pinpoint any point-of-no-return deadlines.Indeed , Dennis Meadows himself has said he doesn't advocate drastic change. In the US, for instance, he says the needed changes can best be made through the free-enterprise system.Speaking to this point last year, he said, ''With debt spiraling, inflation high, agricultural land eroding, and the fresh water supply being rapidly depleted or contaminated, I don't think anyone seriously thinks that current physical trends are sustainable. People like myself think we have to anticipate those problems and deliberately seek changes like tax policies, land-use regulations, and measures like that. I don't see that drastic change is needed in our society to make it more equitable and more sustainable.''