Data Series #3: Biodiversity lost

The third in our occasional series on the ecological sciences looks at biodiversity and the extinction of species. What is biodiversity and why is it important? What do the numbers tell us about how much of it we're losing and why?

Answering these and other question is Dr. Peter Raven, an active member of the Pontifical Academy of Sciences and one of the world's leading botanists and advocates of conservation and biodiversity. For four decades until 2010, Dr. Raven headed the Missouri Botanical Garden, an institution he nurtured into a world-class center for botanical research and education and horticultural display. Described by Time magazine as a "Hero for the Planet," Dr. Raven champions research around the world to preserve endangered plants and is a leading advocate for conservation and a sustainable environment.

Dr. Peter Raven
Photo courtesy of the Missouri Botanical Garden

In recognition of his work in science and conservation, Dr. Raven is the recipient of numerous prizes. He also served for twelve years as home secretary of the National Academy of Sciences and is a member of the academies of science in Argentina, Brazil, China, Denmark, India, Italy, Mexico, Russia, Sweden, the U.K., and several other countries. The author of numerous books and reports, both popular and scientific, Dr. Raven co-wrote "Biology of Plants," an internationally best-selling textbook, now in its sixth edition. He also co-authored "Environment," a leading textbook on the environment.

CE: What exactly is biodiversity and why is it important?

Dr. Raven: Biodiversity is the total diversity of all plants, animals, fungi, of all life forms making up the living systems on Earth. And it’s all the variations within these systems, genetic and otherwise, such as how various environments make similar organisms look different and grow differently.

This diversity is important for several reasons. Fundamentally, we depend entirely on the planet’s living systems for survival. We’re a part of these systems and we cannot exist without them. The better we understand how the systems of life work, the more sustainably we can live. The less we know, the more likely we’re going to continue causing irreparable damage to Earth’s ecosystems.

We should think of all life forms as the endowment of our earth—it’s what we've been given. We have a moral obligation to understand life and manage the systems of life sustainably. In Genesis 2, verse 15, it is written “God took the man and put him in the Garden of Eden to work it and take care of it.” How well are we doing with that mandate to care for the earth, written at a time when the total number of humans on this planet was less than ten percent of what it is now?

Practically speaking, all food comes from plants, directly or indirectly. Ninety percent of our food relies on just over one hundred types of plants. The concern is what happens when we see continued losses of plant species. It’s estimated that one-third of all of the estimated 425,000 kinds of plants could disappear in six or seven decades, which would be about the same percentage of extinction as we estimate for other organisms.

Also, two-thirds of the people in the world depend directly on plants as medicine, many of them in China and India. And about a quarter of our prescription drugs were discovered from plants or are still extracted from them. Of course, we've only looked at a small proportion of the plants.

Tambopata River in the Peruvian Amazon

Photo: Flicker/kingjn

And so the ability to maintain these species is for our benefit—but protecting the various forms of life in the biosphere is something we ought to do just for their beauty and for the joy they bring to our lives. What right do we have to destroy them?

CE: What should people know about the findings of research into biodiversity loss and species extinction?

Dr. Raven: Species are disappearing more rapidly than they have in past 65 million years—and the rate is accelerating. And we’re causing this increase in a number of ways: the destruction of natural habitats; bringing invasive species into ecosystems;  climate change, all caused by a combination of our own population growth and even more rapidly rising consumption levels; and destructive technologies, which drive the overall rate of extinction. In consideration of these factors, a very high rate of extinction is unavoidable. There are three people on earth for every one person who was alive when I was born in the mid-1930s!

CE: How do researchers determine rates of extinction—how do we know species are disappearing so quickly?

First we study the fossil record to determine rates of extinction over very long periods of time, using kinds of organisms that are well represented in the fossil record. We also have some five hundred years of printed books. There is lots we can learn from what’s been written down over those centuries. And then we look around and see which species aren't there anymore. In comparing all this data, we can measure trends and easily conclude the rate of extinction is several orders of magnitude higher than what it has been historically.

CE: It sometimes seems that when asked about ecological problems, people often think first of climate change, running out of fresh water, and water or air pollution as issues of primary concern. Do you believe that issues of biodiversity are given the attention that they are due? Or are they so linked with other issues that any discussion of environmental damage ultimately speaks to losses in biodiversity?

Dr. Raven: Biodiversity and species loss can be difficult to grasp. The concept of so many species, most of which you never see, disappearing, is a kind of abstraction. It’s difficult for people to get excited about something that just doesn't seem to come into focus in their daily lives.

CE: Where has research focused in the past decade and why?

Dr. Raven: There’s a few important areas. One area being researched is in trying to inventory species, to the extent that it can be done. Not counting bacteria, which no one can estimate, there are probably more than twelve million species on Earth—plants, animals, fungi, and microorganisms taken together—and not quite two million have even been recognized and named. And so researchers are trying to build up this list, focusing on groups that are obvious—butterflies, mammals, birds, and mosquitoes, which are important to know about since they are so effective at spreading diseases. By studying these relatively well-known groups we can gain a picture of the pattern of distribution of life on earth. And we’re also trying to get sampling of less obvious groups of life, too, to round out the picture. We can do this partly by comparing their patterns of abundance and distribution with those about which we know much more.

Photo:Flicker/USFWSmidwest

We’re also studying the functioning of ecosystems, in aggregate. Specifically how energy from sun is transferred through algae, plants, and other organisms, and how these systems interact with the water cycle, the cycling of minerals from the non-living world to the living one, and all the ways in which such interactions lead to the smooth function of ecosystems.

There is also a lot of research in the metabolism and genetic characteristics of organisms, to see how they function and how they may be modified for agriculture. Such modifications to the molecular makeup of the organisms can take place in any number of ways, one of which is genetic modification. There is a lot of discussion about this but most scientists are comfortable that genetic modification is not dangerous. In general, climate change and the increased need for food—an estimated one billion people are malnourished now, and our overall population is projected to grow from the current 7.2 billion to 11 billion at the end of the century—will require us to intensify our research into agriculture and improve our agricultural practices greatly.

CE: What can future research help us better understand?

Dr. Raven: In a practical sense we’d like to see as many kinds of organisms as possible be preserved for the future, and to keep as much of their genetic variation as we can as well. That would involve a lot more effort than currently underway. The pressure on the biosphere is enormous already, and then you add our population increase and climate change, it will be increasingly difficult for us to maintain our stock of biodiversity in as complete a state as possibly. In the light of these trends, it is of enormous importance for the preservation of human civilization in the future to save as many organisms as we can, especially those of obvious and particular importance for the functioning of their ecosystems, or for us for special reasons—such as their role in food or medicine, for example.

CE: What steps can governments, civil associations, and individuals take to respond to issues of biodiversity loss?

Dr. Raven: People can learn more about how their actions impact global sustainability. A particularly useful reference for learning is the website of the Global Footprint Network.

We must all think much more internationally than we do now. People can learn continuously, to keep their knowledge up to date, about what is happening to the biosphere and then act on what they come to understand. They can teach their children about biodiversity. Most children are very interested in plants and animals when they are young but they often move on to other considerations as they get older.

Governments can take a wide variety of actions. They can preserve land; develop policies to stop burning inefficient fuels; they can encourage switching to more sustainable methods of food production; they can learn more about organisms in their own borders, and encourage other nations to do the same. They can sponsor many forms of consumption that are less destructive than the ones that are widespread now

The world’s poor will clearly suffer the most because of losses in biodiversity. Their habitats are typically the ones decimated, their agricultural systems deteriorating, the wild plants and animals on which they depend decreases in abundance and all of the conditions of their lives changing for reasons over which they have no control. The situation is plainly morally unacceptable. It’s more than just the effect on indigenous peoples; it’s a matter of the plight of poor people in general that we need to consider.

Especially disadvantaged are often women and children, who in many societies are not brought in to the power structures and given the opportunity to contribute what they could to our overall benefit. When you have more than one hundred million people worldwide at the edge of starvation at any given time, small changes to ecosystems have big impacts. Our consumption levels in the industrialized world, our expectation of an ever-growing prosperity, are increasing based on importing goods from countries less fortunate than ours, and will be even more so in the future if we continue on the present track.This is simply, in a Biblical sense, not taking care to the slightest degree of those less fortunate than ourselves.

CE: What has been your greatest frustration in both researching and teaching this (or related) topics?

Dr. Raven: People are preoccupied by daily life. They don’t take time to reflect on how as a group they impact the larger world. Politicians don’t like to be unpopular, and telling people the truth about their collective effects on the functioning of the earth and what would need to be done, partly by much stronger cooperation between nations than we enjoy now, will always be unpopular. People naturally want more and more for themselves and their families, but when there are so very many of us with such high and ever-increasing demands, it just doesn't work.

One tragic aspect of our lives is that people operate as if their possibilities for consumption are unlimited. This has to change. We need alternate kinds of economies that do not depend on endless growth in a world that cannot support such growth. We need to develop a lot more concern and love for all the people of the earth. Without such changes, there is no hope of solving the enormous problems that we are facing together.

Of course, we will eventually live sustainably, because there is no other option: we can’t go on indefinitely, the way we are. The question is, how much will be left after we consume so much? How much of the world, the joy of the world, has already been decimated and lost permanently? And how much more beautiful, more prosperous, more joyful can it be if we get busy and understand what we’re doing and preserve what we have now to a much greater degree than we might otherwise?

CE: What has been your greatest joy in your work?

Dr. Raven: People are starting to appreciate the problem more and more.

In the 1950s, very few people were concerned about the need for conserving natural resources or biodiversity. And if you think about it, it’s only been a short time since we had wide open frontiers, when everything seemed endless. Now we’re realizing the importance of individual responsibility. People have been taking action as we know more about species losses and see the results of our lifestyles. At the end, it’s a Biblical lesson—concern for those less fortunate than ourselves, moderation in our own lives, conserving rather than destroying. It’s just that the need for applying such principles has become so much greater.

CE: Lastly, is there anything you’d like to add that we haven’t covered?

Dr. Raven: Scientists and scientific findings should be taken seriously. When it comes to issues like climate change or genetically modified foods, scientists should be allowed to let the data say what it says. They operate according to well established standards that continually examine and verify or disprove their conclusions. When data enters into politics, truth becomes opinion and opinions are often based on wishful thinking or the desire to avoid disagreeable actions or taking difficult steps. If such opinions are given a footing equal to that of tested scientific hypotheses, we putting ourselves in real danger at a time in world history when we simply cannot afford to do so.

People often don’t naturally want to do what they have to when they accept what science is telling us about our lifestyles. People don’t always want to think about the future. But you have to when the science is showing us what will happen if we stay on our present course.

Science doesn't tell you not to jump off thirty-story building. It just says what will happen if you do.

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