“Parks, Biodiversity, and Education” by Edward O. Wilson*
This is a very important meeting and book, and I’m grateful to be part of it. First, I’ll summarize what scientists have learned about biodiversity and extinction, especially during the past 20 years. Then I’ll suggest what I believe is the only viable solution to stanch the continuing high and growing rate of species extinction. Then, finally, I’ll make the point already obvious to many of you, that our national parks are logical centers for both scientific research and education for many domains of science, but especially and critically biodiversity and conservation of the living part of the environment.
The world is turning green, albeit pastel green, but humanity’s focus remains on the physical environment—on pollution, the shortage of fresh water, the shrinkage of arable land, and on that great, wrathful demon, climate change. In contrast, Earth’s biodiversity, and the wildlands on which biodiversity is concentrated, have continued to receive relatively little attention. This is a huge strategic mistake. Consider the following rule of our environmental responsibility: If we save the living environment of Earth, we will also save the physical nonliving environment, because each depends intimately on the other. But if we save only the physical environment, as we seem bent on doing, we will lose them both.
So, what is the condition of the living environment, in particular its diversity and stability? How are we handling this critical element of Earth’s sustainability? Let me summarize the basic information that scientists have assembled up to the present time, most of it during the last decade.
First, what is biodiversity? It’s the collectivity of all inherited variation in any given place, whether a vacant lot in a city, an island in the Pacific, or the entire planet. Biodiversity consists of three levels: an ecosystem such as a pond, a forest patch, or coral reef; then the species composing the ecosystem; and finally at the base, the genes that prescribe the traits that distinguish the species that compose the living part of the ecosystem.
How many species are known in the whole world? At the present time, almost exactly two million. How many are there actually, both known and unknown? Excluding bacteria and the archaea, which I like to call the dark matter of biology because so little is known of their biodiversity, the best estimate of the diversity of the remainder (that is, the fungi, algae, plants, and animals) is nine million, give or take a million. Except for the big animals, the vertebrates, comprising 63,000 known species collectively of mammals, birds, reptiles, amphibians, and fishes, and 270,000 species of flowering plants, very little to nothing is known of the remaining millions of kinds of fungi and invertebrates. These are the foundation of the biosphere, the mostly neglected little things that run the planet.
To put the whole matter in a nutshell, we live on a little-known planet. At the present rate of elementary exploration, in which about 18,000 additional new species are described and given a Latinized name each year, biologists will complete a census of Earth’s biodiversity only sometime in the 23rd century.
I’m aware of only three national parks in the world at the present time in which complete censuses have been undertaken: the Great Smoky Mountains National Park, the Boston Harbor National Park and Recreation Area, and the Gorongosa National Park of Mozambique. The Great Smoky Mountains National Park is the most advanced, with 50,000 hours of fieldwork by experts and assistants completed, about 18,000 species recorded, and a rough estimate of 40,000 to 60,000 species considered likely when all transient, rare, or undescribed species have been registered. Fewer than 1%, let me repeat, 1%, of the species have been studied beyond this first roll call. (Incidentally, the largest biodiversity in a North American park would be the one under consideration for the Mobile Alabama Delta and Red Hills immediately to its north.)
Next, what is the extinction rate? With the data sets of the best-known vertebrate animal species, and additional information from paleontology and genetics, we can put the extinction rate, to the closest power of 10, at 1,000 times greater than the extinction rate that existed before the coming of humans. For example, from 1895 to 2006, 57 species and distinct geographic subspecies of freshwater fishes were driven to extinction in the United States by human activity. These losses have removed roughly 10% of the total previously alive. The extinction rate is estimated to be just under 900 times the level thought to have existed before the coming of humans.
This brings us to the effectiveness of the global conservation moment, a contribution to world culture pioneered by the United States. It has raised public awareness and stimulated a great deal of research. But what has it accomplished in saving species, hence biodiversity? The answer is that it has slowed the rate of species extinction but is still nowhere close to stopping it. A study made by experts on different groups of land vertebrates, species by species, found that the rate in these most favored groups has been cut by about 20% worldwide. Furthermore, the Endangered Species Act of 1973, by focusing on recognized endangered vertebrates in the United States, with legal process and processes designed for each species in turn, has brought 10 times more species back to health than have been lost to extinction.
Nevertheless, the species, and with them the whole of biodiversity, thus continue to hemorrhage. The prospects for the rest of the century are grim. All have heard of the 2C threshold, 2°C (or 3.6°F), the increase in the ground average temperature above which the planet will enter a regime of dangerous climate changes. A parallel circumstance exists in the living world.
Earth is at or approaching an extinction rate of 1,000 times above prehuman levels, and the rate is accelerating. Somewhere between a rate of 1,000 times and 10,000 times, Earth’s natural ecosystems will reach the equivalent of the 2C global warming threshold and begin to disintegrate as half or more of the species pass into extinction.
We’re in the situation of surgeons in an emergency room who’ve brilliantly slowed the bleeding of an accident patient to 50%. You can say, “Congratulations! The patient will be dead by morning.”
There is a momentous moral decision confronting us here today. It can be put in the form of a question: What kind of a species, what kind of an entity, are we to treat the rest of life so cheaply? What will future generations think of those now alive who are making an irreversible decision of this magnitude so carelessly? The five previous such mass extinctions, the last one 65 million years ago that ended the Age of Reptiles, required variously 5–40 million years to recover.
Does any serious person really believe that we can just let the other eight million species drain away, and our descendants will be smart enough to take over the planet and ride it like the crew of a real space ship? That they will find the way to equilibrate the land, sea, and air in the biosphere, on which we absolutely depend, in the absence of most of the biosphere?
Many of us, I believe, here present understand that only by taking global conservation to a new level can the hemorrhaging of species be brought down to near the original baseline rate, which in prehuman times was one species extinction per 1–10 million species per year. Loss of natural habitat is the primary cause of biodiversity extinction—ecosystem, species, and genes, all of it. Only by the preservation of much more natural habitat than hitherto envisioned can extinction be brought close to a sustainable level. The number of species sustainable in a habitat increases somewhere between the third and fifth root of the area of the habitat, in most cases close to the fourth root. At the fourth root, a 90% loss in area, which has frequently occurred in present-day practice, will be accompanied by an automatic loss of one-half of the number of species.
At the present time, about 15% of the global land surface and 3% of the global ocean surface are protected in nature reserves. Not only will most of them continue to suffer diminishment of their faunas and floras, but extinction will accelerate overall as the remaining wildlands and marine habitats shrink because of human activity.
The only way to save the rest of life is to increase the area of protected, inviolable habitat to a safe level. The safe level that can be managed with a stabilized global population of about 10 billion people is approximately half of Earth’s land surface plus half of the surface of the sea. Before you start making a list of why it can’t be done, that half can’t be set aside for the other 10 million or so species sharing the planet with us, let me explain why I believe it most certainly can be done—if enough people wish it to be so.
Think of humanity in this century, if you will, as passing through a bottleneck of overpopulation and environmental destruction. At the other end, if we pass through safely and take most of the rest of the life forms with us, human existence could be a paradise compared to today, and virtual immortality of our species could be ensured—again, if enough wish it to be.
The reason for using the metaphor of a bottleneck instead of a precipice is that four unintended consequences of human behavior provide an opening for the rest of the century. The first unintended consequence is the dramatic drop in fertility at or below zero population growth whenever women gain a modicum of social and economic independence. Population growth is slowing worldwide, and the world population has been predicted most recently by the United Nations to reach between 9.6 billion and 12.3 billion by the end of the century. This assumes that the peoples of sub-Saharan Africa will pass through the demographic transition and fertility rates there will drop to levels consistent with the rest of the world.
The second unintended consequence is from the ongoing abandonment of rural, primitive agricultural economies by the implosion of people into cities, freeing land for both better agriculture and the conservation of natural environments by restoration. It’s worth noting also that the present daily production of food globally is 2,800 calories per person. The problem is not food production but transportation and the poor quality of artisanal agriculture. We can fix that. Present-day agriculture is still primitive, with a lot of wriggle room.
The third unintended consequence is the reduction of the human ecological footprint by the evolution of the economy itself. The ecological footprint is the amount of space required for all the needs of each person on average. The idea that the planet can safely support only two to three billion people overlooks the circumstance that the global economy is evolving during the digital revolution, and at a fast rate. The trend is overwhelmingly toward manufacture of products that use less materials and energy, and require less to use and repair. Information technology is improving at almost warp speed. The result is a shrinkage of the ecological footprint. We need an analysis of the trend and its impact. If economists have thought of analyzing this effect and its meaning for the environment, instead of stumbling around in the fever-swamp parameters of the early 21st century, I haven’t seen it.
The fourth unintended consequence is the easing of demand on the natural environment inherent in the evolutionary shift now occurring from an extensive economy to an intensive economy, one that focuses—in the manner of Moore’s law—on improvements of existing classes of products instead of acquisition of new and bigger projects, expanding physical development, and promotion of capital growth based on land acquisition. Humanity may be shifting toward a nongrowth economy focused on quality of life instead of capital and economic power as the premier measure of success.
This brings me to the focal issue of the conference. Inevitably, biodiversity and ecosystem science will move toward parity with molecular, cell, and brain science among the biological disciplines. They have equal challenges. They have equal importance to our daily lives. As this expansion occurs, national parks and other reserves will be the logical centers for fundamental research. They are our ready-made laboratories, in which the experiments have been largely performed. They will also be among the best places to introduce students at all levels to science. We already know that is the case for geology, earth chemistry, and water systems studies. Soon it will be obviously true also for studies of the living environment. Students and teachers alike will have the advantage of hands-on science at all levels. Even at the most elementary level, they are soon caught up in original discoveries of citizen science. After 42 years of teaching experience at Harvard, I believe that natural ecosystems are by far the most open and effective door to science education.
*This excerpt has been adapted (without endnotes) from Science, Conservation, and National Parks (edited by Steven R. Beissinger, David D. Ackerly, Holly Doremus, and Gary E. Machlis; 2016).
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