Global Deforestation

The past three years have seen the publication of two major works on the loss of tropical forests and its potential effects— Norman Myers's Conversion of Moist Tropical Forests; and Tropical Forest Resources, a study of seventy-six tropical countries conducted by the Food and Agricultural Organization and the Environment Programme of the United Nations. Both of these have generated great interest in deforestation and have raised a number of important questions. This seems to be an appropriate time to examine some of the problems associated with the loss of tropical forests. For example, is all deforestation undesirable? What types of problems might it create? Are they global or local in nature? Which of the potential impacts will actually be realized?

On May 2, 1983, Resources for the Future, the Lincoln Institute of Land Policy, the World Environment and Resources Council, and the International Institute for Environment and Development sponsored a conference to discuss some of these questions. Speakers were Norman Myers, author of the 1980 report on tropical forests and an environmental and development consultant; Julian Simon, visiting fellow at the Heritage Foundation, on the faculty of the Universities of Illinois and Maryland, and author of The Ultimate Resource; Peter Raven, director of the Missouri Botanical Garden, president of the American Institute of Biological Sciences, and the author of several works on tropical biology; and Roger Sedjo, director of the Forest Economics and Policy Program at Resources for the Future. The moderator was Robert Goodland, environmental affairs officer at the World Bank. Pierre Laconte, president of the World Environment and Resources Council, was the commentator.

The article that follows has been prepared from the speeches and the discussion.

Effects of deforestation

ROGER SEDJO: There appear to be four separate and identifiable types of potential problems arising from deforestation. First is the question of industrial wood supplies; second, the availability of fuelwood; third, environmental impacts; and fourth, the loss of unique plant and animal species. Each of these can, in principle, be either local or global in scope, or perhaps both.

Since industrial wood and wood-using products are heavily traded internationally, availability of supplies is a global problem. A particular country need not be self-sufficient in wood, but there should be areas of surplus or deficit and some international trade, balancing out the needs and production of a region. For a number of reasons, future supplies of industrial wood do not seem to be in jeopardy.

By contrast, the fuelwood issue is almost entirely local or regional and, as such, is in principle amenable to solutions at the local level. It is clear that fuelwood scarcity is a serious problem in some regions of the world.

Environmental problems can be either local or global. Clearly, numerous serious local environmental problems are caused by deforestation—both in the tropics and elsewhere. However, there is little evidence of serious global environmental damage related to current rates of deforestation. The 1982 Carbon Dioxide Review states flatly, "No one any longer suggests land-use changes will produce a significant fraction of man's total future releases of CO,. If there is a carbon dioxide problem in the future, it will be due to the burning of fossil fuels, not the burning of forests."

Finally, there is the question of losing genetic resources. Enough evidence exists to suggest that this is certainly a potential, and probably an actual, problem. However, it is difficult to assess the extent and seriousness of the problem. Estimates of future losses of species are, at best, the crudest of guesses and are made more difficult by lack of reliable information on past losses. Thus, projections of losses over the next twenty years are, at best, very tenuous. Nevertheless, there are reasons to believe that genetic resources concentrated in tropical forests may experience excessive rates of destruction. It also is clear that habitats housing unique genetic resources are threatened, particularly in coastal Brazil and Madagascar.

Most of the problems of excessive deforestation are related to the common property nature of that resource. A resource that belongs to everyone ultimately belongs to no one and is exploited not only beyond its biological sustainability, but also beyond its economically optimal level. Hence, neither ecological nor economic criteria are satisfied. Enlightened policy, therefore, must recognize this reality and design institutions that will address this problem.

There has been a tendency to seriously overestimate the extent of global and tropical deforestation. Nevertheless, for some regions and in some locations, the rate of deforestation is excessive by both ecological and economic criteria.

Second, there are serious existing fuelwood and environmental problems in many locations. These require remedies that recognize the common property nature of these resources and may involve important local institutional changes.

Third, there are serious potential problems related to the protection and preservation of the world's genetic resource base; again, institutional changes are required to afford these resources adequate protection.

Safeguarding tropical forests

NORMAN MYERS: My fundamental finding is that tropical moist forests are undergoing outright elimination at the rate of 9.1 million hectares a year, and they are also undergoing gross disruption and biological impoverishment at a rate of 10 million hectares a year or a little more.

Tropical forests cover less than 7 percent of the earth's surface, and yet they contain almost half of all species on earth. Nowhere else is there this extraordinary concentration of life forms, many of which could benefit mankind. Yet so far less than 1 percent of all those species has been examined. If the arthropods are included, the figure is more like 1/100th of a percent.

I think a case can be made for saying that the species found in tropical forests represent one of the most valuable and unique stocks of natural resources. The paradox is that despite the many goods and services they offer, tropical forests rank among the least developed of all natural resource stocks on earth—developed in the sense that they provide material products and environmental services on a sustainable basis and serve long-term human needs.

On the other hand, they are being exploited for timber, for cattle ranches, for food for a few people. Hardly any of this exploitation is planned and managed.

The key question is not how to safeguard all the tropical forests; the questions we must ask are much more complex and much more relevant: Which sectors of tropical forests should be utilized and how should they be utilized? What sort of needs should they meet and over what period of time? Finally, what are the costs of a particular use compared with others?

I would like to suggest that development of tropical forests can include "wise use" for less established, though equally valid purposes, to go along with more traditional uses. If the emphasis is on sustainable, overall outputs of tropical forests, such services can be seen as a form of development that ranks alongside timber harvesting. A national park is just as legitimate a use as a paper pulp plantation. Genetic reservoirs are as important as forestland agriculture, and in certain localities use can entail outright preservation of forest ecosystems for scientific research. Wise, planned use would not only benefit mankind, but would leave a lot of tropical forests standing at the end of this century and, more important, at the end of the next one.

Species preservation

JULIAN SIMON: Based on a memo by Thomas Lovejoy, the Global 2000 Report said in its "Major Findings and Conclusions" section: "Extinctions of plant and animal species will increase dramatically. Hundreds of thousands of species—perhaps as many as 20 percent of all species on earth—will be irretrievably lost as their habitats vanish, especially in tropical forests." I submit that this prediction is based on virtually no evidence.

The proximate source of the assertion is a book by Norman Myers, The Sinking Ark, from which these key points may be extracted.

1. The estimated extinction rate of known species between the years 1600 and 1900 was about one every four years.
2. The estimated rate from 1900 to the present was about one a year.
3. Some scientists (in Myers's words) have "hazarded a guess" that the extinction rate "could now have reached" 100 species per year. In other words, that estimate is simply conjecture and is not even a point estimate but rather an upper bound.
4. Even the guessed upper limit in (3) is then increased and used by Myers, and then by Lovejoy, as the basis for the "projections" quoted above, which calculate to about 40,000 species lost per year.

That is, an upper limit for the present which is pure guesswork, and which is a hundred times the observed rate in the recent past, has become the basis of a forecast for the future which is 40,000 times greater than at present and has been published in newspapers to be read by tens or hundreds of millions of people and understood as a scientific statement. Looking at the two historical points alone it is clear that, without explicitly bringing into consideration some additional force, one could extrapolate almost any rate one chooses for the year 2000, and the Lovejoy extrapolation has no better claim to belief than a rate, say, 1/100th or 1/40,000th as large.

This reanalysis does not imply that species are in no danger. As I see it, it implies that much more careful analysis, including cost—benefit analysis of the resources devoted to saving species versus other uses of value to mankind, is necessary before there is reasonable basis for policy recommendation. Can you now share my view that the available evidence does not support the frightening conclusions that are drawn from it?

I do not intend to suggest that our society and humanity at large should not worry about possible dangers to species. But we should strive for as clear and unbiased a view of this set of assets as possible in order to make the best possible judgments about how much time and money to spend in guarding them in a world in which this worthwhile activity must compete for funds with other worthwhile activities.

A delicate balance

PETER RAVEN: The World Bank estimates that 600 to 800 million, or one out of every three people in the tropics, is living in absolute poverty. By the end of the century, about 60 percent of the earth's people will be living in the tropics, owing to an unequal distribution of population growth. Clearly, these people will have no recourse in most cases but to turn to the tropical forest for their sustenance, increasing the rate of deforestation and destroying the plant and animal populations of those forests.

The relationship among organisms in tropical forests is the most intricate and tightly linked example of mutualism and interaction among organisms found in any biological community in the world. Scientists are only beginning to learn a little about the way that energy and minerals flow through tropical ecosystems and are recycled. Because of this delicately balanced exchange of nutrients, about which we know so very little, tropical forests are among the most easily disturbed of any in the world.

There are, in temperate regions, about 1 million known species of organisms and probably 1.5 million unknown. Any group of organisms which is reasonably well known has twice as many species in tropical regions as it does in temperate regions. A conservative estimate is that there are at least 3 million species of organisms in the tropics, about 500,000 of them known.

In coastal Brazil, 95 percent of the state of Bahia has been deforested. 98 percent of western Ecuador has been deforested in the past twenty years. Only 7 percent of the vegetation of Madagascar persists in some semblance of natural order. There are about 12,000 species of plants in Madagascar, about 7,000 found nowhere else, and they are confined to those pockets of the remaining 7 percent of vegetation.

Quibbling about extinction rates in the face of what is actually happening in the tropics is tantamount to watching a forest fire raging down a mountainside and saying, "Well, we ought to do something about that forest fire, but first let's find out a little more about the nature of fire."

Very little research is being done anywhere in the world on how to convert tropical forests into productive systems. The tree plantations that exist are in warm, temperate areas and not in the tropics at all or are in southern parts of Brazil.

It is evident in the face of the rapidly growing human population that every inch of the ecosystem will need to be fully used. The problems of doing this must be recognized.

Extinction—Now or later?

THOMAS LOVEJOY, World Wildlife Fund: As has been mentioned, there are millions of species in the tropics and there are simply not enough scientists available to work on the problem of the rate of extinction. One has to approach it from a slightly different point of view.

Certainly, the whole exercise should always be a matter of projections rather than a matter of predictions. It is probably difficult and unreal to try to convert the figures into rates. That assumes we know something about the shape of the curve of tropical deforestation out into the future.

My own approach is to look at the problem in terms of the area of deforestation versus the number of species that might be lost with that area. In doing this it is important to realize that secondary tropical forests hold a very tiny fraction—probably less than 5 percent—of all the species found in the great, skyscraper-like primary forests of the tropics. In addition, it is very important to recognize that large deforested areas in the tropics, because of the nature of tropical ecosystems, have very slow recoveries, perhaps infinitely slow in terms of the human experience. If one ignores the Global 2000 estimates for the moment and merely asks what the shape of the curve should be when the amount of tropical forest area lost and the number of species lost are related, then one begins to get something that is free of time considerations.

One could choose a curve that goes up much more rapidly than a linear relation-ship, indicating that deforestation is expected in areas containing concentrations of species with limited distributions. Or one could assume that the deforestation will aim away from some of these key areas. That, in fact, was one of two curves that I chose in doing my calculations in the Global 2000 report. The important thing is that however the estimates are done, and rough as they are, the numbers come out to be fairly large. I used numbers because people think of endangered species as individual things rather than as part of a continuing process of biotic impoverishment.

I would contend that—as important as it is to determine precise rates of tropical deforestation, if only to get a better grip on this problem—in a sense all we are arguing about is the date of extinction.

Carbon dioxide emissions

MARION CLAWSON, RFF: I think there is one aspect of deforestation that has been rather regularly overlooked. That is what has happened to the volume of wood harvested and its net contribution to carbon dioxide in the atmosphere.

When forests are cut, they are not invariably immediately retranslated into carbon dioxide. Sometimes, indeed, the wood is burned and the conversion is much quicker than if the wood had rotted slowly. But sometimes, and particularly in the temperate zone forests, the wood is converted into usable forest products and may stay in that form as long as it would have stood in the forest had it not been cut.

I have done some rough calculations that indicate there is half as much wood fiber outside of the forests in the United States today as there is standing in the forests. I think that in the past two generations, U.S. forests have added substantially to the amount of carbon dioxide embodied in wood rather than in the atmosphere.

I strongly suspect that if one constructed the best possible model of what has happened over the past generation, the past century, one would find that forests, instead of contributing to the carbon dioxide of the atmosphere, globally have removed at least as much carbon dioxide as they have contributed.

This is a line of inquiry that is worth pursuing—that is, the volume of wood involved, not merely the acreage.

Commercial versus noncommercial losses

EMERY CASTLE, RFF: I think there is agreement that species have value and the when species are lost, we have lost something of value. I believe everyone also agrees that when we make commercial uses of tropical forests, we sometimes sacrifice noncommercial uses, of which species loss is one example. If that is so, then it seems to me that there needs to be discussion about how one measures or compares commercial loss—or commercial use as contrasted with the noncommercial loss.

Are we suggesting that all commercial uses be eliminated? I think not. But if not, what commercial uses are going to be permitted and how are they going to be related to the noncommercial losses that everyone is concerned about? It has been suggested that the possible basis of the problem is a property right issue, that in some cases there is open access to these resources—resources of real value to humankind—and yet there is no real discipline governing the ways in which they are used.

Regeneration

ELLIOTT NORSE, Ecological Society of America: What has not been discussed is the rate of regeneration of forests. If, as Tom Lovejoy has pointed out, secondary forest has 5 percent of the species of primary tropical forests, then it is important to know what the rates of regeneration are. No matter what the acreage is, the question still is very germane. How fast are the primary forests regenerating? Will they regenerate quickly enough so that losses in one place are compensated for in another? If not, we are losing forests as the world's population increases. Something will have to give somewhere.

Another point that has not been brought up is the rate of evolution versus the rate of extinction. Some species evolve rapidly, but for many others it takes tens of thousands to hundreds of thousands of years to evolve. On the other hand, it takes only a very short time to wipe some species off the face of the earth. The inevitable consequence, it seems to me, of increasing activity, increasing extinction, and evolutionary rates that probably are not increasing at all or are being slowed, is that species will be lost.

More important than this is that the confidence we have in various kinds of data varies. For example, different projections of human population growth come within a few hundred million folk by the year 2000 or the year 2050. On the other hand, for how many species of insects do we know the intrinsic rate of natural increase? The answer is a very, very, very small fraction. That figure is just as important to the question of species loss as is the human population growth rate.

Tropical forests and economic development

MICHAEL ARNOLD, United Nations Food and Agriculture Organization: I have heard very little that recognizes that tropical forests, as a major natural resource which is mobilized and turned into capital, can contribute to the economic development of tropical countries.

Unfortunately, the exploitation of the tropical forests is not resulting in capital accumulation, largely because most of the forests are being destroyed and not used. This is happening also because the part that is being used is exploited; the value of forest products is accruing, not in the tropical countries, but largely in the industrialized countries to which they are exported.

Then there is the fact that tropical forests are one of the largest remaining land banks, containing probably considerable areas of land which could or might be put to better use under agriculture. Unfortunately, much of the land that is being cleared to produce food is not capable of sustaining agriculture, at least with the techniques available to the poor farmers who are practicing agriculture. The result is the destruction of the land resource.

Surely this is a major reason for describing tropical deforestation as "catastrophic." It is not only destroying the immediate land of the tropical forests, but through erosion, flooding, and silting, is destroying or damaging or degrading huge areas outside the forests that have been previously put under agriculture.

Future considerations

PIERRE LACONTE: There are a few conclusions that can be drawn here. First, there is an urgent need for more research, and there is also a potential for it. It is therefore urgent that additional funds should be allocated.

There is another problem, and that is that satellites constitute an important research tool for studying this problem, but the equipment is expensive and the results of data collection often are not available to the countries faced with deforestation. Some way of transferring this information is needed.

The fact that this conference has agreed on some of the problems and the necessity to know more about them does not bring us nearer to the solution. The solution lies in the heads of the people. You cannot plant trees on the ground before you have planted them in the heads of the people. I think that it is extremely important to explore ways to change attitudes at national and individual levels.

There are in the literature a number of experiments at community levels which have proved very successful, for example, in Korea and in Gujarat in India. I think these opportunities can be explored not only from a scientific but from an institutional viewpoint and that it is urgent to do so.

NORMAN MYERS: We know less about the workings of ecosystems than any other systems on earth. In view of this ignorance, we need to adopt a cautious attitude to our use of tropical forests. As in other circumstances of uncertainty, it would be better to find that we have been vaguely right than certainly wrong. The face of the earth is being changed so very fast that in many circumstances we cannot wait to accumulate sufficient evidence to make a decision.

ROGER SEDJO: The rate at which forests are being denuded is important, for a number of reasons. For one thing, it has direct implications for the rate of irreversible species losses; the slower the rate of deforestation, the more time there is to adjust to it.

We also have to recognize that the world is dynamic. In much of the northern hemisphere, net afforestation is taking place. I will not suggest that that is necessarily going to happen in the developing world and in the tropics, but it is conceivable that there could be adjustments there.

If some forest resources are less accessible, and the rate of deforestation is down, that has implications for species preservation, and is a positive sign. On the other hand, it is clear there are serious problems—population increases apply pressure on the resources. Institutional changes are needed to deal with those kinds of problems and we have to start thinking about institutional structures that will preserve resources.

ROBERT GOODLAND: If a tropical forest is cut, 80 percent or more of the nutrients are gone forever. They are washed out to sea. The forest will not come back; one has only to look at some of the lunar landscapes wherever deforestation has been allowed to proceed to see the truth of this irreversibility.

The ecosystem provides services to make people—protection from floods, attenuation to climate, provision of water in the dry season—and these services are orders of magnitude more important in the tropics than they are in the temperature zones. If tropical forests are cut down, massive erosion may result. That is why many people are made homeless practically every year in Bangladesh and India. I would like to firmly dispel the notion that tropical deforestation is useful. It is not. At most, it gains three harvests for a peasant before he is compelled by declining yields and increasing waste to move on and cut another patch of forest. Even at that level, he can barely survive.

The other gains from cutting tropical forests, I submit, are similarly tenuous and ephemeral. Since biological resources are the most essential natural resources supporting human existence, the cautious approach should prevail. The number of species being lost because of deforestation is almost immaterial. Acceptance of even some extinction can be construed as being one of the ultimate arrogances of our time, for it denies the value of these species to all future generations.

Ruth B. Haas, an editor in RFF's Public Affairs Division, prepared this article from the conference transcript.