Thank you Steve Hubbell. And I can say without hyperbole, because I said it with complete sincerity at the time of its publication, his neutral theory of community organization is revolutionary in its own right and is, as one reviewer has called it correctly, an instant classic. He is surely in the foremost rank of our ecologists, a rarity who has made major contributions in theory and also through a lifetime of field research composed empirical studies of diversity as it actually exists. Friends, colleagues, thank you for giving me this opportunity to present the Chafee Memorial Lecture. I take it as a signal honor to present a lecture in memory of John Chafee, a great patriot (what pleasure it gives me to be able to use that word unabashedly), a great senator, and a great environmentalist. I consider it an exceptional honor to do so here in the Smithsonian, and in Washington — from which emanate so much policy and action that affect the world environment. As we peer forward, well into the 21st century, which is really the business of this conference, it will serve well to ask this question: What might we have overlooked about our place in history? What are we most at risk of forever losing, most likely toward the end of the century? The answer, I think, is this: much of life, the rest of life, or the creation if you will, a lot of our environmental security, and just as important, part of what it means to be human. Our relations with the rest of life can be put in a nutshell: scientists have found the biosphere (and this has been due in good part to work just in the last few decades) to be richer in diversity than ever before conceived. And that biodiversity, which took over three billion years to evolve, is being eroded at an accelerating rate by human activity. The loss, to conclude this synopsis, will inflict a heavy price in wealth and security and spirit.
The bottom line in global economics, I suggest, is different from that widely assumed by our leading economists and public philosophers. They have mostly ignored the numbers that count. Consider the following: the world population has now edged well past six billion and is on its way to nine billion or more by mid century, before mercifully peaking and starting to descend. Per capita fresh water and arable lands are dropping to levels that resource experts consider very risky. The key statistic is the ecological footprint — which is the average amount of productive land and coastal marine environment appropriated by each person (not in a single block, for example, around where you might live in Maryland or Texas, but in bits and pieces from around the world) needed for your food, water, housing, energy, transport, commerce, and waste management. Each person, for example, on average draws down a little bit of Costa Rica for coffee, a little bit of Saudi Arabia for oil, and so on. In the developing world, with five billion of the six billion people, the ecological footprint is about two-and-a-half acres. In the United States it is ten times as much: about 24 acres. For every person in the world to reach present American levels of consumption with existing technology would require four more planet Earths. The people of the developing countries may never want to attain our level of profligacy, but in just trying to achieve a decent standard of living, they have joined the industrial world in converting the last of the natural environment and reducing a large part of the planet’s fauna and flora to endangered status or final extinction.
At the same time, Homo sapiens have become a geophysical force. We have driven atmospheric carbon dioxide to the highest levels in at least the last 200,000 years, unbalanced the nitrogen cycle, thinned the protective ozone layer of the atmosphere, and initiated global warming that will ultimately be bad news everywhere. Our unbalanced relation to the natural environment began a long time ago as a mistake in capital investment. Humanity, having appropriated the Earth’s natural resources during the Neolithic Revolution (starting 10,000 years or so ago) chose to annuitize the resources with a short term maturity reached by progressively increasing payouts. That’s basically what we have done and are doing. At the time that seemed a wise decision, and viewed in the short term it still does. After all, the result is rising per capita production and consumption markets awash in oil and grain — and also in optimistic economists cheerfully monitoring GDPs and competitive indices.
But there is a problem. The key elements of natural capital, as opposed to market capital (in other words, Earth’s arable land, groundwater, forests, marine fisheries, and petroleum) are finite and not subject to proportionate capital growth. They are furthermore being decapitalized by over-harvesting and habitat destruction. Therefore with population and consumption continuing to increase up and up, the per capita amount of resources left to be harvested is falling and destined to be harvested at a faster and faster pace in the future. The long-term prospects are not promising.
Humanity, awakened at last to the realities of the natural economy that underlies the market economy, has begun an earnest search for alternative sources of materials and energy. Altogether the 21st century is destined, in my opinion and that of many here I suspect, to be the century of the environment. The immediate future is usefully conceived as a bottleneck. Science and technology, combined with a lack of self-understanding and a paleolithic obstinacy that led to our ruinous environmental practices, have brought us to where we are today. Now science and technology combined with foresight and moral courage and common sense, both drawn from a more enlightened ethic than has hitherto ruled public philosophy, must see us through the bottleneck and out, one hopes, by the end of the century.
There are two collateral effects of the bottleneck phenomenon worth reminding even this exceptionally well-informed group. The first is: the rich grow richer and the poor grow poorer. The income difference between the fifth of the world’s population in the wealthiest countries and the fifth in the poorest countries was 30 to 1 in 1960, 60 to 1 in 1990, and it’s now 74 to 1. Eight hundred million people remain in what the United Nations classifies as absolute poverty: no sanitation, no clean water, rampant disease, and periodic starvation. Even if the income differential is dismissed as a humanitarian issue, it should be considered a security issue. It is a setting for resentment and fanaticism and the arrival of suicide bombers seeking a better world somewhere else.
But the second collateral effect (and the one to which I’ve personally paid a great deal of attention and want to address more fully tonight) is the accelerating destruction of the natural environment leading to the mass extinction of ecosystems and species. The damage already done can’t be repaired within any period of time that has meaning for the human mind. The more it is allowed to grow, the more future generations will suffer for it in ways both well understood now and still unimagined. “Why,” future generations will ask, “by needlessly extinguishing the lives of other species, did you diminish our own?” The radical reduction of the world’s biodiversity is the folly our descendants will least likely forgive us.
Let me review some of the basic facts now concerning biological diversity (or biodiversity for short). First of all, what is biodiversity? It is all of heritable variation of life on Earth. To rescue that from banality, biologists recognize and analyze separately biodiversity at three great levels of organization, starting with ecosystems. The next level down is species, which compose those ecosystems and range enormously in size and ecological function. And the third level is genic variability within the species.
How much biodiversity is there? We now estimate that about 1.5 million to 1.8 million species of plants, animals, and microorganisms have been described. And it’s a bit of a scandal, as Steve Hubbell was indicating, that we don’t even know how many species we’ve already accounted for. Among those species we know, of course, the insects and the flowering plants dominate in diversity, that is, in numbers of species. The reason for that is simply that they formed a partnership toward the end of the Mesozoic on the land (which has such highly diverse topography and opportunities for isolation of populations and species formation) and together pumped the world’s biodiversity up to the high level that we have today. If you were to look at this in what we call the speciesscape, where each major group is represented by a single organism in proportion to its group’s size, insects would be represented by, for example, a beetle, which would loom like a Goodyear blimp over a minute elephant (representing the paltry 4,500 species of mammals, the group to which we belong). And then of course there are the fungi: 60,000 to 70,000 species known, but experts estimate that there are over one and a half million species out there, and therefore they have considerable representation in the speciesscape. This brings me to the point of the exploration of this planet.
We do not know to the nearest order of magnitude how many species of plants, animals, and microorganisms there are on Earth. It’s almost certainly more that 5 million, it could be 10. But it could be, particularly due to the unknown depths of variation of species composition of bacteria and archeans (the single cell, very primitive organisms that form the foundation of all ecosystems), as high as 100 million. We don’t know. We just haven’t begun to explore the biosphere. We live on a little-known planet with a razor thin biosphere, so thin you can’t even see it edgewise from a space shuttle, that contains such enormous complexity that we haven’t really explored it properly. We know less about it than we do the surface of Mars and the moon.
The black hole of biodiversity is the bacteria. And the next level down is the diversity of genes we have just begun to explore, the genetic variation within species. Just to give you a feeling of how great that variation is, or the amount of genetic material, if you took the four strands, the four molecules that make up the total composition of a single genetic composition from the nucleus of a single human cell (somatic cell), and you put them end on end, you get in real space a molecule about a meter long, but it’s only two billionths of a meter wide — you can’t see it. If you could magically enlarge that molecule to the size of the width of wrapping string, then our single cell material would stretch approximately 1,820 miles. That would be from New York to Dallas. And if you walked along that string, ticking off the base pairs that make up the letters of the code, you’d be counting about 100 every inch. A lot of that is unique to Homo sapiens, as it would be to a fungus, a small insect, a Sequoia, and so on. This image will give you an idea of what we lose when we allow one species to go extinct. The average age of a species before the coming of humanity was very roughly 1 million years. We’ve speeded up extinction and thus shortened that span by roughly 1,000 times. The amount of information that is lost is approximately equal in pure bits to all of the editions of the Encyclopedia Brittanica published since the eighteenth century.
Where is biodiversity located? Everywhere there is liquid water or the potential for liquid water. Pole to pole from the summit of Everest to the challenger deep at 36,000 feet below the ocean surface, there are at least bacteria and other microorganisms. These include microscopic fungi, some of which also thrive in water above the boiling point in the thermal vents from the sea floor, supercooled water in the Antarctic ice gardens, and two or more miles below Earth’s surface drawing energy from the metabolism of inorganic chemicals and therefore independent of life above. (The organisms down there incidentally — to make them easy to remember — are called the SLIMES. That stands for Subterranean Lithoautotrophic Microbial Systems. That will be on the exam.)
Most of the species of known organisms occur in tropical moist forest — tropical rainforest. It covers about 6 percent of the Earth’s land surface and is down to about half of what it was before humanity began cutting it. The tropical rainforest is still largely unexplored. The part that is least explored is the canopy, where the photosynthesis occurs and where we know there is an enormous amount of biological diversity. It’s been very hard to get into because of the difficulty of climbing trees in the tropical forest. These typically go straight up until they begin to branch near the canopy. Their surfaces are typically smooth or have spines, and when you get up to the top there are these gardens of epiphytes — gesneriads and orchids and even cacti — that are densely packed together on the branches. These are homes to swarms of stinging wasps and ants. Tarzan would not have survived 15 minutes. So it’s been a challenge for our more athletic young men and women who want to get up there. One of the methods that are being developed include using a crane, as is being done in a pilot experiment of the Smithsonian Tropical Research Institute (STRI). When the investigator gets out onto the arm of the crane it circles around, and the investigator is able to lower himself up and down. An enormous volume of rainforest canopy can be reached. But the investigators just can’t hang there, they’ve got to have a protected cage with a door — because the Africanized, so-called “killer,” bees are very abundant, and you don’t want to bump into a nest hanging 100 feet above the rainforest floor. Investigators are able to travel around almost as though floating through air and get out to the tips of the trees — the branches — where people have never been before and so much of life is concentrated and the productivity of the forest is based.
The diversity of these rainforests is legendary. From a single tree I identified, for example, 43 species of ants living in the tree including 26 genera (and that’s about equal to the total diversity — total number of ant species — found in all the British Isles). But one doesn’t have to go to tropical rainforests to see great and unexplored diversity. In just an ordinary forest, say mixed hardwood and conifer forest around here, you can see a world that is still far beyond our understanding. The forest floor looks two dimensional as we walk over it and look down (like Godzilla in New York City), but it’s not. If you cut it — come into it from the side, magnifying it greatly so you’re looking at a cross section from the dead leaves at the top of the litter and down a few centimeters — you can see a number of zones in which the size of the space is declining and in which the leaves are being increasingly chopped up and converted. You’re also getting changes in chemical composition, in nutrients available, in temperature, in light. You therefore have an immense array of niches at a micro level. These are real niches into which vast numbers of species have radiated in their evolution and specialized to fill. Their existence is what keeps these forests healthy. These are what we lose — this diversity — when we, for example, convert old growth forests by clear cutting in favor of second growth or tree farms.
Now on a personal note, here is the way to get many young people into science. Most young people have a “bug period” — or they are capable of having it. They have a true and unabashed sense of wonder, and they can still work directly in nature and derive enormous pleasure from it. And then not only can they live a more fulfilling life by knowing what lies out there to see and wonder about and explore as they reach maturity, but also if they want they can go into a scientific career — this is one of the broad pathways into a scientific career. And believe me, it’s environmental science that’s going to count in this century.
It is the destruction of habitat where we are doing the most damage to the diversity of life. Habitat destruction is at the top of the ways human activity is destroying biodiversity. NASA has found that about five percent of the Earth’s land surface is burned every year. Five percent. And that includes vast areas of the Amazon Orinoco basin and the Congo basin, which are still mostly sparsely inhabited. The destruction has been — terrifying is the only word I can use to describe it when you see the maps through time of how the forests have been reduced in some of the biologically richest areas of the world. For example the magnificent Mata Atlantica, the Atlantic forest of Brazil, one of the real hot spots of the world, has been reduced to less than ten percent of the original forest cover. Fortunately, the Brazilians now have begun serious conservation and restoration projects for this particular forest area.
I wish I could say the same for the Philippines. In the last hundred years, the forest there has been mostly destroyed. Now we know with a fair degree of precision how much of the biodiversity we lose as the area comes down in size. This is a subject that both Steve Hubbell and I have worked on, for example, among other investigators. As you go from the large islands of the West Indies — we can use this as a model field situation — the large islands such as Cuba and Hispaniola down to the smallest islands like Saba, the number of species drops off, depending on the group and the geographic area, between the third and sixth root for the most part. The fourth root is a very commonly used figure. Now if you take the fourth root just as an example, this means that with a 90 percent reduction in area (to 10 percent of the original cover) you will eventually lose roughly half the species. They will be either eliminated immediately or doomed to early extinction.
We can see this occurring for example in our national parks, which are “habitat islands.” They are well protected, but you can picture them as islands of natural environments in an increasingly hostile sea of ranch land and other converted forest and grassland. And sure enough, the species have been declining. They’re declining to a new level which may or may not be equilibrial now, but in time it probably will be equilibrial. There is an actual decline overall of mammal species in 14 national parks in western North America. None of the 299 mammal species in these parks has yet become globally extinct, that is extinct in all the national parks and elsewhere. But there is a cumulative curve leading toward extinction in all of these parks combined. The tropical rainforest is disappearing worldwide at the rate of about one half a percent to one percent a year. The remaining cover of rainforest is about equal to the coterminous 48 states, and the rate of destruction is equal to from half to all of the state of Florida each year. This translates to as much as a quarter of one percent of the species in these rainforests extinguished or doomed to early extinction each year.
In addition to the destructive effects of habitat loss should be added invasive species. Invasive species are alien species that are destructive in some way either to humanity or to the natural environment. And they include the “friendly” fire ant from South America, a gift of Brazil and Uruguay to the southern United States, a major pest. I don’t know if it’s actually extinguished any species yet, but it’s markedly modified much of the insect fauna from the Carolinas to Texas. Another example of an invasive species — and probably the most repellent — is the brown tree snake from the Solomon Islands or New Guinea, which was introduced to Guam shortly after the Second World War and proceeded to build up enormous populations of a thousand or so per square mile. It grows to about eight feet long. It’s poisonous and it specializes on birds as prey — it has wiped out virtually all of the native land birds of Guam.
The flood of invasive species around the world is growing, partly as a result of globalization. And every part of the world is receiving invasive species from somewhere. Hawaii has been largely taken over in the lowlands by invasive species. What you see in Hawaii is largely a fauna of alien species. Rarely would you ever see a native bird on the islands. You see a few native plants and a few native insects, but mainly the biota is reconstituted from species that occur in other parts of the world, a synthetic fauna. To give you an example of how extensive it is, I recently sent two assistants to the Juan Fernandez archipelago, which is this remote group of islands off the coast of Chile. It had never been collected for ants, and I had to know, I just had to know what was out there! They brought back collections, which included the fearsome Argentine ant (which is such an enormous pest in California and Australia and really destructive in South Africa). They discovered that the species has taken hold on these remote islands and appears to be spreading rapidly.
How fast are species going extinct? By two separate measures, the area-species curve, and by tracking individually the velocity of species traveling through the IUCN red data for 40 years, we have estimated the current rate of extinction worldwide of species is conservatively between 100 to 1,000 times higher than it was before the coming of humanity — when it was very roughly one species per million per year. And some believe that those brackets are too low, that the increase could be on the order of 10,000 times higher. Because as entire ecosystems are eliminated, as in those Philippine forests, the rate jumps dramatically up as you approach the end game, and the forest or whatever it is, is shrinking toward unsustainable amounts of resource. It’s entirely possible then, some analysts say even likely, that if the present rate of habitat destruction and spread of alien species continues, and that’s a big if, because it depends on how committed we are to doing something about our living environment, we could lose half the species of plants and animals on Earth by the end of the century.
Hawaii is a dramatic example of how drastic local extinction can be. We now know, due partly to excellent work done here at the Smithsonian, that there were upwards of 140 species of birds on Hawaii before the arrival of the Polynesians in 400 A.D. And they included Hawaiian eagle, flightless ibis, huge gooselike birds with bills like those of a tortoise, and many other remarkable forms — including many beautiful honeycreepers. Now only 25 are left. The Polynesians wiped out quite a few and European and other colonists after the 18th century wiped out a great many more. Of the 25 that are left, most are endangered to some degree and a couple of them are so endangered they’re not expected to survive more than a few more years.
Let me turn to the bottleneck, the period we are now in, in which the greatest challenge is to raise the lives of people everywhere to a decent level, while bringing through intact as much of the natural environment as possible. That would be my suggestion as the great goal of the 21st century. Its two objectives are intertwined. They are synergistic in such a way that progress in one enhances progress in the other.
I’ll close then with a dispatch from the global biodiversity front, where I’ve been active on the Boards of Directors of several of the major conservation organizations, to tell you a little of what is being done about the hemorrhaging of ecosystems and species and how the problem can be partly solved. First, it turns out that large blocks of the last remaining natural environment and wilderness areas can be preserved at surprisingly low cost and in such a way as to yield greater profit. This is what counts also to the countries owning them. It’s as simple as this: logging companies, which we have sort of intuitively thought must be economic juggernauts that cannot be stopped, are actually operating on a very thin profit margin and they can be out-bid by conservation groups using private gifts which are then leveraged by grants from the Global Environment Facility, the World Bank, and other organizations for as little as $10 an acre and often much less. Conservation concessions, as opposed to logging concessions, can be established in countries otherwise prepared to give away logging rights cheaply. It is possible to turn the policy around 180 degrees to preserve the forest instead. Or a trust fund can be set up the same way with the proceeds being paid to the country for preserving and managing large reserves. Or the logging rights can be purchased, in some cases for as little as $1 an acre. Or finally the land itself can be purchased outright. By these means, for example, Conservation International and The Nature Conservancy have recently added over 2 million acres to the parks and reserves of Bolivia, Guyana, and Suriname. They and the World Wildlife Fund are also offering research and management expertise to promote the use of this land to the countries that own them. Income from tourism and other non-invasive income sources can quickly be made more profitable than timber leases and agricultural conversion. Other developing countries around the world are now exploring similar arrangements.
Another point of entry is the preservation of “hot spots,” those particular forests and coral reefs and other local habitats that are both endangered and contain the largest number of plant and animal species found nowhere else. Twenty-five of the terrestrial hot spots cover only 1.4 percent of the land area of Earth but are the exclusive home of an astonishing 45 percent of all known species of vascular plants and 36 percent of mammals, birds, reptiles, and amphibians. In other words, a large minority of the world’s known fauna are limited to 1.4 percent of land, which is not overwhelmingly expensive to preserve. This is an approach promised by Conservation International and the World Wildlife Fund among American-based NGOs to provide the means for moving swiftly to save, or at least put in a holding pattern, a substantial amount of the world’s biodiversity.
Not all of the hot spots are in remote jungles. Some are close at home, the Hawaiian rainforest for example, the temperate rainforest in the Pacific Northwest, the coastal sage scrub of California, and the Lake Wales Sand Ridge of central Florida are among America’s leading hot spots. These are among the parts of the U.S. on which resources should be focused immediately and with some urgency in order to save a large part of the diversity of life — and it can be done.
It is clear that progress in global conservation — and I think this is a conception that has been very well and repeatedly illustrated today and in today’s session — is dependent on joint enterprises of the private sector, government, and science, a true iron triangle. We have to know exactly what is at stake, what is the status of many of the endangered species, what most needs to be done to save them, how to do it, and how to develop a strategy of aid and development attractive to people everywhere and to their governments. And to allude to the bumper sticker problem posed by Science Editor Don Kennedy this morning, we have to learn how to sweep constantly back and forth between local and global to get the job done. Right now it’s the private sector, working through environmental non-governmental organizations, that forms the spearhead of the global conservation effort, particularly by invention of new and cost-effective methods. The largest of these organizations, including Conservation International, The Nature Conservancy, IUCN, World Wildlife Fund US, and World Wildlife Fund International are reaching operating budgets in the $100 million level. They are acquiring enough influence to form partnerships with the World Bank and the United Nations, as well as to work with the CEOs of larger corporations. They are backed by hundreds of smaller NGOs, operating in cities, countries, and internationally. The NGOs are in general more entrepreneurial, innovative, and flexible than governments. But make no mistake: governments, especially those of the industrialized countries, still must do the heavy lifting and will have to assume a much larger role in the future. At the present time about $6 billion a year is spent worldwide on conservation. Proceeding from both private and government sources, most of it ultimately from government, a recent estimate suggests that about $28 billion annually is needed to sustain a sample of all the world’s natural ecosystems, marine as well as terrestrial, and a large part of the biodiversity. But as a first step, $28 billion in one investment, as estimated by economists and biologists in the Defying Nature’s End Conference held at Cal Tech last year, wisely placed in hot spots and tropical wilderness areas could save upwards of half or more of the species. One payment. And if that seems a large price to save so much of nature and biodiversity, keep in mind that it is only one thousandth of the combined gross domestic product of the world, that is, the annual combined gross domestic product. One thousandth.
The central problem of the new century, in my opinion and to repeat, is therefore how to raise the poor to an endurable quality of life, making them partners in the conservation effort worldwide while preserving as much of the natural world as possible. Both the poor and biological diversity are concentrated in the developing countries. The solution to the problem must flow from the recognition that both depend one on the other. The poor, especially the nearly one billion who remain absolutely destitute, have little chance to improve their lives in a devastated environment. Conversely, the natural environment, where most of the biodiversity hangs on, cannot survive the press of land-hungry people who have nowhere else to go. I hope that tonight I’ve added to the conviction, which I know is widely shared here and by growing numbers of other thoughtful people of all walks of life, that this problem can be solved. We can now concentrate on solutions. We cannot afford to accept anything less than proposed solutions with a timeline and a concrete goal and a budget and a way of recruiting people. These are the prerequisites to shifting the paradigm of the economy of the world, in which the market economy is joined sustainably to the natural economy. Those who control the resources to do this must be recruited. They have many reasons to accept that goal as a necessity, not least their own security. At the end of the day, however, the direction we take will be an ethical decision. All politics is ethical, even if just in lip service, and it will be an ethical decision to launch a true and effective global and environmental rescue operation. We should, as a matter of principle, save every scrap of biodiversity that we can hold on to. A civilization able to envision God and an afterlife and embark on the colonization of space will surely find the way to save the integrity of this planet and the magnificent life it harbors. Thank you.
This is a chapter from The Future of Life (Lecture).
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