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2001 - The Land

The Philosophical Society of Texas

“The Land” was the topic of the 164th anniversary meeting of the Philosophical Society of Texas, held at Austin’s Marriott at the Capitol Hotel on November 30-December 2, 2001. A total of 334 members, spouses, and guests attended. President Ellen C. Temple organized the program, and Robert Breunig of the Lady Bird Johnson Wildflower Center moderated.

The meeting began on Friday with lunch and a tour of the Lady Bird Johnson Wildflower Center, followed by a reception and dinner at the University of Texas Alumni Center. The evening featured readings by Liz Carpenter, Steve Harrigan, Elizabeth Crook, Tim Henderson, and Karen Kuykendall on the topic of “The Land We Know.”

President Temple announced the new members of the Society and presented them with their certificates of membership. The new members are Gregg Cantrell, Joyce Pate Capper, Betty Sue Flowers, Donald S. Frazier, Israel J. Galvan, Dee J. Kelly, Adair Wakefield Margo, Kathleen Shive Matthews, Paula Meredith Mosle, Raul Rodriguez, William A. Wise, and Robert E. Witt.

Frank D. Welch, an architect with Frank Welch and Associates in Dallas, received the 2000 Philosophical Society of Texas Book Award for the best book on Texas, either fiction or nonfiction, published in 2000. His Philip Johnson & Texas was published by the University of Texas Press.

Members and guests gathered for a reception and dinner at the Bob Bullock Texas State History Museum on Saturday evening. Attendees enjoyed the museum exhibits, which remained open for viewing during the evening, and danced to the music of Corkey Robinson and the Keynotes.

At the annual business meeting, held on Sunday morning, Vice-President George C. Wright read the names of Society members who had died during the previous year: Charles Nelson Prothro, Ralph H. Shuffler, and Dan C. Williams.

Secretary Ron Tyler announced that Society membership stood at 196 active members, 68 associate members, and 36 emeritus members.

Officers elected for the coming year are George C. Wright, president; J. Sam Moore, first vice-president; Alfred F. Hurley, second vice-president; J. Chrys Dougherty III, treasurer; and Ron Tyler, secretary.

An open discussion on “The Future of the Land” concluded the meeting, and President Temple declared the meeting adjourned until December 6,2002, in Fort Worth.

 

 

Welcome and Introduction

Welcome to Austin and the 164th anniversary meeting of the Philosophical Society of Texas. Although my home is in Lufkin, the heart of the Pineywoods in East Texas, I chose Austin, the heart of Texas, for our annual meeting because the city can more easily accommodate our large group. I also wanted to give you the opportunity to tour the beautiful and peaceful Lady Bird Johnson Wildflower Center, which about 100 of you did yesterday. Mrs. Johnson has inspired me and countless others to love and value our native plant heritage. I would like to dedicate this program in honor of Mrs. Johnson.

I chose “The Land” as our program today because I think that its care is the most critical issue of our new century. We have to get this one right. As Mrs. Johnson has said, the land is the one place where we all come together—it is our home. At the same time, issues relating to the land (which I define as soil, water, plants, and animals) divide us. As a state and a nation, we are searching for common ground, a place where we can agree enough to act and to create public policies that will keep our home beautiful and healthy.

“The Land” seems to be a huge topic, but not nearly as huge as the late Bill Crook's 1995 program “The Oceans” or Steve Weinberg's 1994 program “The Controversial Cosmos,” both of which I thoroughly enjoyed. Today my hope is that we will leave this annual meeting with the same sense of wonder about the land that those two earlier programs evoked about the sea and the heavens.

I'm grateful for all of the help that I had for this program. Last night at our reception and dinner at the University of Texas Alumni Center, located on the banks of Waller Creek, which flows past the campus, through town, and on into the Colorado River, we set the stage for today's program with a delightful presentation of readings: “The Land We Know,” organized by our own Liz Carpenter, an author and former press secretary of Lady Bird Johnson. For sharing their stories and songs of the Texas land we know and love, I thank Liz as well as authors Steve Harrigan and Elizabeth Crook, who read from their own books; actress Karen Kuykendall; and songwriter and singer Tim Henderson.

I'm also grateful for the special help that the following experts gave me for this program today: Dr. Robert Breunig, executive director of the Lady Bird Johnson Wildflower Center; Dr. Steve Windhager, director of the Landscape Restoration Program, Lady Bird Johnson Wildflower Center; Dr. Jay Banner, director of the Environmental Science Institute of the University of Texas at Austin; and Terry Hershey and Jessica Catto, two of Texas's leading environmentalists. I also thank Tom Barrow of Houston for giving us the maps that show the ecological regions of Texas. And, of course, I thank Evelyn Stehling, assistant secretary for the Society, for all of her hard work in helping to plan and organize this program and the events for the weekend.

As we focus on “The Land” today and in our panel discussion tomorrow, we will learn more about some of the most pressing issues we face, how we can best deal with them, and what the future holds.

It is my privilege to welcome and to thank our distinguished speakers. After their presentations, you will have the opportunity to ask questions.

Dr. Robert Breunig, known as Bob to those of us who have worked with him over the years, has been the director of the Wildflower Center since 1997. I was president of the board at the time, and I cannot begin to tell you how happy we have been to have him aboard. He came to us as past director of the Desert Botanical Garden in Phoenix, where he developed his passion for native plants. Bob is a leader in the native plant movement and also a member of the Philosophical Society. Bob will present an overview and also serve as the moderator.

Dr. Laura L. Jackson, of the University of Northern Iowa, will give our keynote address with her answer to the question “What Does It Mean to Love the Land?” Her new book is entitled The Farm as Natural Habitat: Reconnecting Food Systems and Ecosystems.

Dr. Camille Parmesan, of the University of Texas at Austin, has focused her work of the past several years on the impact of climate change in the twentieth century on wildlife. Her work on butterfly range shifts as been featured in many scientific and popular press reports. She will speak on "Global Warming and the Changing Land."

Dr. David Schmidly, president of Texas Tech University, has spent thirty years studying Texas landscapes and natural history. He has authored five major books about Texas mammals, and his most recent book, Texas Natural History: A Century of Change, chronicles the modem history of landscape change in the state and its impact on the fauna. The topic of his presentation is "A Century of Land Use in Texas."

Dr. Libby Stem, of the University of Texas at Austin, will also explore issues close to home with her presentation "Soil and the Edwards Plateau." She applies her specialty of isotope geochernistry to understand earth surface processes both in the modern environment and in the geologic record.

Dr. William R. Jordan III, director of the New Academy for Nature and Culture, is the founder of the journal Restoration & Management Notes (now Ecological Restoration) and a founding member of the Society for Ecological Restoration. His new book is entitled The Sunflower Forest: Ecological Restoration and the New Communion with Nature. He will answer the question "How Can We Heal the Land?"

Andrew Sansom, former director of the Texas Parks and Wildlife Department and now director of the International Institute for Sustainable Water Resources at Southwest Texas State University in San Marcus, will speak on "Texas Land and Public Policy."      

Our closing panel for the day will focus on national policy and "America the Beautiful." Jessica Catto, who brought this distinguished group of panelists together, will serve as the panel moderator. Melinda. Taylor of Environmental Defense; Larry Selzer, vice president of Sustainable Programs, the Conservation Fund; William E. Debuys Jr., who chairs the Valles Caldera Trust in New Mexico; and Pat Noonan, the founder and chairman of the board of the Conservation Fund, will give us a close look at nongovernmental agencies' work on a national scale.

On Sunday morning, Robert Bruenig will serve as moderator for a summary session, "The Future of the Land." Joining in the discussion will be Laura Jackson, William Jordan, Andy Sansom, Libby Stem, Jessica Catto, and Camille Parmesan.

 

I will now turn the program over to Dr. Beunig and our distinguished speakers with my warm welcome and thanks for their participation.

 

What Does It Mean to Love the Land?

Thank you very much, Bob, and thank you, Ellen, for inviting me here to visit with such a distinguished group of people. I really am honored to be able to address you and to visit with you. You have given so much to your state, as I'm learning at the various events we've attended together so far. There are so many areas in which you've contributed to the state in terms of higher education, literature, art, music, business, philanthropy, architecture, folklore, history—the list just goes on.

Your accomplishments remind me of a saying that my mother taught me, "Of those to whom much has been given, much will be expected." Clearly, you have expected a lot from yourselves, and the topic of this gathering illustrates your dedication to serious reflection on philosophical issues affecting our times.

My task is to explore the question, What does it mean to love the land? The first thing I should do is to clarify that question by asking, What do we mean when we say "land"? And even scarier perhaps, What do mean when we say "love"?

When I was in college, this business of definitions seemed to me a way for the professor to stall for time. Now that I am a professor, I see that stalling for time is not always a bad idea. After exploring this issue of what land is, I will try to illustrate some of the problems that I see in loving the land, with examples from my home state of Kansas and from my adopted home of Iowa.

Then I'm going to make a case that loving the land is kind of like loving thy neighbor—a tremendous responsibility, a very difficult task that we will never completely accomplish, requiring hard and strategic choices, not only at a personal level, but at the level of society and culture.

What do we really mean when we say "land"? There is, of course, the common vernacular meaning: the landscape, the scenery outside a moving car or on a park trail. Last night we were treated to wonderful descriptions of the diverse land forms of Texas from the Chihuahan Desert to the High Plains. From the Hill Country to the Piney Woods to the Gulf Coast, this is an obvious source of pleasure and pride to Texans and a genuine way, a real way, of loving the land. There's also the way we see land when we fly over it, abstractly, as a picture puzzle of different colors and textures, different owners, different land uses, all dissected by rivers, roads, and the various topographic features of the land. There's another way we experience land as gardeners, paying close attention to soil, to light, to rain, as we plan and plant, as we hoe and harvest.

These are the vernacular definitions, but they are not complete. If we combine the aerial view of land with the gardener's view, we begin to approach the sense of land as an ecosystem. I'm an ecologist, so that's the way that I have tried to develop my understanding of land. From an ecosystem perspective, land includes animals, plants, the climate, and the marvelously complex living medium that we lump under the word "soil."

Land, in this sense, includes the air flowing above and the water flowing through. It includes processes like photosynthesis and nutrient uptake in plants (carbon fixation from the atmosphere). It includes assimilation of plant energy and nutrients by animals as they eat plants, the pathways of energy and nutrients up the food chain, and later on their decomposition by the action of invertebrates and microbes in the soil.

Fire, flood, and wind are part of ecosystems. For instance, what would South Florida look like without hurricanes? Hurricanes are an intrinsic part of the South Florida ecosystem. And what would a flood plain be without floods? Flooding is not a disaster; flooding is a natural part of the ecosystem.

The ecologist's view of land also extends beyond the common, immediate time scale. What we see on the land today is merely a snapshot; an ecological vision requires us to see land changing over decades, centuries, and even millennia. In decades a tree can grow; in centuries a forest can replace a prairie, a delta can form, a river can change course. In millennia a new soil horizon can form. A climate can go from warmth to ice, and new species can evolve.

Let us adopt the most rigorous and inclusive view of land. Land includes not only wilderness, parks and open scenery, but urban land, suburban shopping malls, and farm land. When we talk about land, we need to talk about all of those lands, not just the stuff we think of as scenery.

Finally, most critical to an ecologist's definition of land is that it includes human beings. We are connected to the oil fields of Iran and Alaska, the coal mines of Appalachia and Wyoming, the hard rock mines of Brazil and the Congo.

We are what we eat; we are physically what we eat. Our bodies are physically part of all the land we eat from—vegetables and fruits from California; bread from Kansas; pork from Oklahoma, Missouri, Iowa; chickens from Alabama and Tennessee; potatoes from Washington and Idaho; shrimp from Belize and Thailand. Our bodies are physically connected to and part of those ecosystems. And in turn we are very much affected by the way food is produced.

The zone of hypoxia or low oxygen in the Gulf of Mexico about 7,000 square kilometers, last I checked, is almost dead. Excess nitrogen flowing out of the Mississippi River from the Midwest fertilizes the Gulf, increasing the amount of algae, and as that algae decomposes and falls to the bottom of the ocean, the oxygen is sucked out of the water by microbes. Gulf Coast fishermen sell their boats.

Eat a steak and become part of the Gulf of Mexico ecosystem. I can't emphasize strongly enough that this is a physical reality, just as real and direct as a baby nursing from its mother tastes the broccoli she had for dinner.

So what does it mean to love all the land, the land in its fullest and most complete sense? It means having your heart broken again and again. To paraphrase Aldo Leopold, the father of the modern conservation movement and a Midwesterner, the consequence of an ecological education is that you live in a world of wounds.

Let me show a few images of the land that I love.

This is the Kansas River. I grew up in Salina, but my folks on my dad's side come from the Topeka area, and the Kansas River flows from west to east through wheat, through sorghum and cattle country. It's fed by the Smoky Hill, the Saline, the Solomon, the Blue, the Vermillion, and comes to its confluence with the Missouri River near the Missouri border.

This land is land that my brother Scott has spent most of his adult life on. He frames houses in the Lawrence area. He loves to hunt and fish. He spends almost all of his free time on this river and in the bluff lands above it. Finally, a couple of years ago, he was able to afford to buy a little piece of land along the Kansas River, his little piece of paradise.

Here he is with my daughter Nettie and his daughter Abigail. It's paradise almost. On this hot June day that we took out kids to the sand bar, my brother warned me that the girls weren't going to be able to splash in the cool water on the edge of the sand bar. There was a permanent health advisory; the water is too dirty to swim in. He can't take his daughter fishing there either because the fish have high levels of pesticides in them that limit consumption to eight ounces every six months for an adult male.

There is less and less of this river to show our girls. Long ago when he started college, he used to be able to see large shoals of freshwater mussels on the bottom of the river. The United States is home to the largest diversity of freshwater mussels in the world, and over 70 percent are imperiled or extinct. Now, he rarely even sees a dead mussel, rarely even sees a shell. These were killed off by sediments and excess nutrients in the water.

Growing up, my brother and I used to explore the sand bars and fish and swim in the Smoky Hill River next to our home. This was a major part of our bonding as children—and, I believe, of my beginnings as a biologist and his beginnings as a sportsman and naturalist. Our children must be held back and taught not to touch the river, as if it were a garbage can in a public restroom. This is a hurt that I can only begin to describe.

Now, let's move to Iowa, another beautiful state, a state of prairies. At the time of the European invasion, 85 percent of the land was prairie and wetland. The prairie developed over the last 10,000 years as plants migrated back in and the glacier melted. Every summer the plant roots grew deep and died, depositing organic matter in the rubble left by the glaciers. Cold winters and wet springs kept the organic matter from oxidizing or decomposing, so it accumulated deep in the soil horizons.

Many parts of the state have eight or more feet of black soil and subsoil. Just to give you an idea what that means in terms of agricultural productivity, I found a map that shows Iowa and other states sized according to the value of their agricultural output. It makes Iowa the biggest state in the Union—even bigger than Texas!

Less that one-tenth of 1 percent of this tallgrass prairie remains. The remnants are small; the largest remnant in eastern Iowa is about 240 acres. Most are in the five- to ten-acre range, and people do back flips when they find a new four- or five-acre prairie.

Let's compare what the landscape looks like now with the prairie ecosystem. Once covered with perennial roots, covered with plants that held the soil in place and soaked up the rainfall and snowmelt, this is now a land of row crops. Because corn and soy beans grow over a very narrow window of time, this land stays essentially bare seven months out of the year.

The remaining prairies are often tiny. I once found a prairie between two farm fields that was about 18 inches wide. Despite being the rarest ecosystem in North America, tallgrass prairie remnants continue to be plowed under every year, especially after land changes hands.

We have also affected the land in other ways. The herbicide atrazine can be detected in all of our surface waters twelve months of the year and has contaminated a major reservoir in the state that is the water supply for several communities.

Des Moines, Iowa, had to build a special reverse osmosis plant, the largest plant in the world, to take nitrates out of the water. This plant was designed to run about two weeks out of the year to mix clean water with other sources of water until they had diluted the nitrates enough to make it legally drinkable. But last year the plant ran for about a hundred days.

Iowa lakes and rivers are distinguished by having the highest levels of nitrogen and phosphorous in the world, according to U.S. Geological Survey data, and we are responsible for a disproportionate share of the Dead Zone in the Gulf of Mexico, also according to the USGS. About 50 percent of the nitrogen that is applied to our cornfields this fall will reach its intended crop; the rest will head toward you.

Iowa has also lost about half of its original topsoil since the time of European settlement 140 years ago. We started off on average with 18 inches and we now have on average nine inches. Hans Jenny has calculated that a good inch of topsoil takes 300 to 1,000 years to develop, so we've already burned up several thousand years' worth of topsoil.

Although the U.S. Natural Resource Conservation Service says that most of the erosion is at tolerable rates now, this is hard to believe sometimes. We have unpredictable rainfall, and on July 3 of 1999, when the corn was still small, a large portion of eastern Iowa got nine inches of rainfall in twenty-four hours. The soil was virtually unprotected, and there was more soil loss from this one storm than had occurred on those fields in ten years or more.

When my husband and I moved to Iowa in 1993, I knew that I was moving to a state that was involved in industrial agriculture. However, I wasn't quite prepared for just how industrial it was becoming. The new trend in the late 1980s and early 1990s was the conversion of a very democratic form of livestock production, raising hogs, into a corporate activity that was concentrated in large buildings called hog confinements, or confined animal feeding operations (CAFOs).

These CAFOs can hold 10,000 finishing hogs. That means they are growing from about 30 pounds to about 150 to 200 pounds before they're marketed. Most are corporate owned or raised by contractors.

Longtime rural residents, many of them hog farmers themselves at one time, began to complain. Hearings were held; there was all kinds of strife. They were saying that they couldn't let their children play outside anymore because of the stench, because they became nauseous. They couldn't hang their clothes on the line anymore; they couldn't open their windows on a warm summer night; they couldn't even have friends over for a barbecue and stay outside. And they couldn't sell their houses. People complained of flies, nausea, depression. The official reply was that odor is psychological and extremely subjective.

Just as an aside, I did a study with a colleague at Iowa State and a rural resident to look at manure-management plans in an area of very high concentration of hogs. Our study contained 60,000 finishing hogs in about four square miles.

We looked at the amount of nitrogen excreted by those hogs and determined that it was about 1.8 million pounds per year of nitrogen being released in that area. Almost three-quarters of that nitrogen went straight into the atmosphere as ammonia, and then that comes back down in the rainfall over a larger area.

They were applying nitrogen three times the rate recommended by Iowa State. They were applying nitrogen to soybeans, which is a legume which fixes its own nitrogen, so they were essentially throwing it away. The levels of phosphorous that they were applying were ten times that recommended by Iowa State.

The troubles of concentrated livestock are already well known. We have already seen the concentration of cattle into huge feed lots and chickens raised by the millions in small cages. We are now beginning to see 5,000-cow dairies in California and Wisconsin at the expense of small family farms. And I should mention that in Iowa between 1992 and 1997, we went from 34,000 hog farmers to 17,000. By 2001, there were 10,500 farmers selling hogs in Iowa while the total number of hogs sold remained steady.

This is happening all over the country, not just Iowa. I saw, as I was flying over, 200 such hog barns, probably somewhere in Missouri or Oklahoma. We who eat—that's all of us—are physically connected to these ecosystems. Even if we don't live there, we are physically connected.

I think most of us are aware at some level that when we eat we are violating our obligation to be good stewards of creation through our association with these practices. Aldo Leopold says, "Conservation is a state of harmony between men and land. Harmony with land is like harmony with a friend; you cannot cherish his right hand and chop off his left. That is to say, you cannot love game and hate predators; you cannot conserve the waters and waste the ranges; you cannot build the forests and mine the farm. The land is one organism." This is another way of saying that we have to pay attention to all the land, not just the parts that are pretty right now.

Most of us would not have it so if we could help it. If you want to learn more about the food system, I suggest you read Fast Food Nation by Eric Schlosser, a very good book that exposes the way that we eat and the system of how we distribute food and connects that with all sorts of other larger social issues, environmental and social.

The good news is that we can help it; we are not stuck, or if we are stuck, we're not stuck that far from the road. In the book that my mother Dana Jackson and I have recently published, The Farm as Natural Habitat: Reconnecting Food Systems and Ecosystems, we make the argument that the agricultural landscape we see now is inevitable. Many of the book's contributors know farmers who are already making a solid living and improving the soil, water, and biological diversity on their land. The Farm as Natural Habitat stems from the conviction that the agricultural landscape as a whole could be restored to something better. The destruction of every last shred of nature is not a necessary compromise for the survival of the family farm, or because of the need to "feed the world." We maintain that the trend toward sterile, industrialized agriculture is an unacceptable, unaffordable sacrifice; that it is far from necessary, and that we can help farmers reverse it to benefit nature conservation, rural communities, farm families, urban residents, and consumers.

I'd like to briefly introduce you to a few of the farmers we highlight in the book.

Tom Franzen is now an organic farmer, but in 1977 he was a progressive, high-chemical-input farmer. In that year the pope came to Iowa, and he was listening to the pope's message on the radio as he painted his barn. The pope said that the land is ours to take care of for future generations. Tom said he started to shake so much that he had to get down off the ladder. He spent the rest of the day walking around his farm and reflecting on his role in land stewardship. After that he stopped using insecticides, afraid of what they would do to his family and the soil. When I met him in 1993, he was in the process of drastically reducing his herbicide use.

By 2001 he had eliminated all herbicide and chemical fertilizer on his place, and he was marketing his hogs and soybeans organically. He called me up one day, jubilant. He said, "You know, you think you're committed to organic, but you're not really committed until you get that first bean check." He was paid $19.50 per bushel when the price for conventional beans was $5.40. You can afford to get lower yields raising organic crops.

An important element of Franzen's success is his use of holistic resource management techniques. This is a formal process involving the whole family of defining one's values and goals—personal as well as financial and environmental. Once the goals are identified, then the farmer asks how ecosystem processes on the land can be managed to achieve these goals.

Another farmer I would like to talk about is Mike Natvig. He and I worked on a project to convert some of his pastures to prairie—while still grazing them. He raises cattle using rotational grazing methods. They are moved from one pasture to another throughout the summer so they always have fresh grass and the remaining grass is allowed to rest.

Pastures in the upper Midwest are composed almost entirely of European, cool-season grasses and clovers. This is different from Texas and many parts of the Great Plains where cattle still graze on native grasses. Our goal was to restore native biological diversity to his farm without asking him to give up his income from cattle. Mike is also a founding member of Prairie's Edge Sustainable Woods Cooperative, the goal of which is to get better income from woodlands while protecting soil, water, and native biological diversity.

I'd also like to describe a wonderful three-year study led by the Land Stewardship Project in Minnesota. Six farmers and twenty researchers from the University of Minnesota were brought together to study and monitor indicators of economic, social, and environmental health on these farms. The farmers had recently converted from conventional dairying (where the cows are fed grain and hay rations usually raised on the farm) to rotational grazing (where the cows are led to fresh grass each day and feed themselves). Many of these farmers were losing money doing things the way the state agricultural college recommended, so they decided to cut costs and increase their profit margins while accepting lower milk yields using this methods.

One of the most surprising and exciting parts of the study was the bird monitoring. Farmers became expert bird watchers as they learned to recognize grassland-nesting migratory birds in their pastures. These birds, like Eastern Kingbirds, meadowlarks, bobolinks, and dickcissels, wouldn't go near their corn and alfalfa fields. But once they converted those fields to pasture, the birds began to recognize good nesting habitat.

What do these farmers have in common? They're curious, they're interested in their family's well-being, and they're not locked in to what everybody else thinks they ought to do. They're very independent-minded people. And I would say that they're very empirical; they look very carefully at exactly what the land is telling them, and they respond to that.

Public policy has created a lot of this problem. The current farm bill that's being discussed in Congress has to do with recognizing and rewarding farmers for the multiple benefits that they provide to society—not just feed, food, and fiber, but watershed protection, wildlife habitat, a pleasant rural scenery. Previous farm policy has benefited a few very large grain companies like Archer Daniels Midland and meat processors such as Tyson and IBP.

There are other kinds of public policy that we can learn from out there. In Great Britain they very readily recognize that agriculture and nature are not far apart, that they're really part of the same thing, and that their farmers have a large role to play in conserving the biological diversity of their plants, their butterflies, and their birds. They recognize the value of a beautiful countryside.

It's a nation of amateur naturalists, and they have done a wonderful job of documenting everything that they have. After World War II, a lot of practices were changed. Land uses intensified, more of their diverse, low-productivity pasture land was fertilized, and more of their pastures and hay meadows were plowed up for crops.

Current conservation policies in Great Britain have created an agri-environment scheme in which farmers in certain sensitive areas are rewarded for foregone income if they graze their animals in a more traditional manner that conserves the rich plant diversity of the chalk grasslands.

Hay meadows that even Shakespeare wrote about, with very high levels of wildflower diversity, also were under assault after World War II, and a few of them are now protected. They're harvested for hay in management schemes that maintain that biological diversity, and farmers are rewarded for that. So there are many options out there; there are many ideas that we can learn from.

I'd like to close with a few thoughts about love. Now, I've only been married eight years. Most of you have been probably married longer, so I'm treading on thin ice here. There are people with more insight into this than I have, but there are a few pieces of conventional wisdom that I think we can learn from here as we relate it to the land.

First of all, we celebrate our loved ones' gifts and we appreciate their strengths, but we also accept their weaknesses. We don't try to change them, and this is true of the land as well. Rain does not follow the plow, as our pioneers ancestors thought. You cannot change the land by plowing it; you will not increase the rainfall. It is still an arid country, and that is something that we have to accept. It doesn't do us any good to try to blow past that one.

Similarly, we can prevent floods by damming rivers, channeling them and harnessing them, but we pay the cost. There is a species of fish in the Missouri River called the pallid sturgeon. That group of fishes has been alive in North America for 60 million years, and it's currently endangered because of channelization and dams. We pay the cost when we try to change ecosystems beyond their original character.

A second truism about love—little things mean a lot. Small individual gestures add up to big parts of our lives. Small little things? What am I talking about? Nitrate molecules. Carbon dioxide molecules. These are little tiny things that we add every day through driving our cars, through fertilizing our fields inefficiently, and we tend to forget about these little things but they add up in big ways, and we see the results in global warming and dead zone in the Gulf of Mexico and other estuaries around the world—the loss of beautiful coral reefs as a result of fertilization, the loss of those mussels in the Kansas River, the loss of the ability of our children and grandchildren to swim in those waters.

Antibiotics are a little things. We currently feed antibiotics to livestock as growth promoters, not to help when them when they're sick, and bacteria are building resistance to the main classes of antibiotics. Fluoroquinones are the main class of antibiotics fed to hogs for growth promotion, and Cipro is a fluoroquinone. So we are rapidly increasing the risk that we will lose Cipro as a tool to treat Anthrax because we want the pigs to grow faster. Other countries have banned subtherapeutic uses of antibiotics and have done so without all of their farmers going out of business. Little things mean a lot.

And finally, let's not confuse momentary attraction to physical beauty with real love. Love involves responsibility and work. I have a six-year-old and a two-year-old—a lot of work. We all know that love involves commitment as well as great joys and satisfaction.

So what does it mean to love the land? Well, first, land is a big, big thing, bigger than we think it is, bigger even than Texas. And love is a strong, strong word. You can't just say it. You have to show it.

 

An Overview

Thank you. I've really looked forward to moderating this session and to working with this distinguished panel in talking about such a vital subject—the land.

I wanted to set the tone for today's discussion by telling you a personal story about my own understanding and awareness of the land. I began my career as a cultural anthropologist, and I worked in northern Arizona among some of the Indian tribes there. And in 1982 I moved from Flagstaff to Phoenix, which was a huge change for me.

I don't know how much you know about Arizona, but Flagstaff is at 7,000 feet in a beautiful pine forest. It's a great place to live. Those of us who lived in Flagstaff thought of Phoenix as essentially the hellhole to the south. Phoenix was in the Sonoran Desert, and in our language the word "desert" tends to mean an empty and barren place. Having grown up in the Midwest, that's essentially how I looked at the desert.

When I moved to Phoenix,  my job was to put together a major exhibition at Phoenix's museum of anthropology called the Heard Museum, and my specific assignment was putting together an exhibit called Native Peoples of the Southwest. So as a part of that process, I began to talk to and interact with a number of people from that region.

One day I was sitting around a table with a group of elders from the Tohono O’odham tribe and talking about the exhibit we wanted to prepare. I kept saying that we wanted to describe "how you all survive in the desert," and I used that phrase several times. Finally, one of the elders looked at me very sternly across the table, raised his hand, and stopped me. "Dr. Breunig," he said, "we don't survive in the desert. The desert is our home. We live here."

Well, at that moment I just wanted to slide under the table. But it was one of those moments when you really come to understand something more profoundly. What I then understood was that the Tohono O’odham are people of the desert, and this is reflected in their very word for themselves—Tohono, desert; O’odham, people. They had lived for a thousand years in that desert, and they had a deep and intimate understanding of the land of the desert. To them, it was not an empty, barren place where they had to "survive," but a rich and beautiful place. In fact their word for desert is "bright and shining place."

They knew of 300 species of plants that they could use for food alone. And when we think of people who come out of hunting and gathering traditions, we think of them simply wandering around the environment, grabbing something here and grabbing something there.

But that is not the case. Their knowledge was much more intimate, and they had to know how to be at exactly the right place at the right time. Certain foods became available within a very short frame of time. They also had to know exactly how to get the food and how to process it. This was knowledge that was accumulated over a very, very long time.

I thought about the fact that I now was living in the desert too, and I thought about the implications of that concept on my own life. I thought about my upbringing in Indianapolis, Indiana, and what I learned about that land when I was growing up. Now, don't get me wrong. I went to a very fine school. I took biology classes, and I learned some basic things. But I have to admit that I did not have any intimate knowledge of the particular landscape in which I grew up.

I think that's also true for most of today's young people. We are living in a culture that is essentially disconnected from the land, one that does not have a particularly deep and intimate knowledge of the land. I'd like to suggest that this is a problem because it leads us to make bad decisions about the land, and it causes us to look at the land in ways that may ultimately be damaging to it.

This comes across to me in simple little ways. For example, I'm working with some people here in Austin on a development project, and I always recoil somewhat when they start describing the land as, “Well, that's the dirt out there, and we're going to put so many units on the dirt.”

That particular land that they're talking about is essentially critical for the quality of the water for the city of Austin. That land is alive, and does a lot of basic things. It performs what we call ecosystem functions. If the land is disturbed, damaged, or destroyed, it can't do those things for us. Then we have a decline in the water quantity and water quality, and we're subject to more flooding.

So we've got to see the land in a different way and understand that it does things for us that have fundamental value. These things are so basic, have gone on for so long, and are so much a part of everything around us that we don't even see them anymore. And, therefore, we don't value them. We have to recognize that value and bring it into our equations and into our understanding.

I actually have a great deal of hope for the future because, in my work at the Wildflower Center, I see that young people, in particular, have an enormous amount of interest in the land and in interacting with it. Some of our young staff at the Wildflower Center—Steve Windhager, the director of our restoration program, was mentioned earlier—see the land as something to be interacted with, to be actively involved with in terms of restoration, not something to be simply preserved or set aside.

I want to predict that in the last half of this century a major part of the activity of this culture will be in restoring and rehabilitating land that we have lost and degraded because it will be essential to do so to restore the ecosystem functions and to maintain the health of our land, our economy, and ourselves. So I'm hopeful for the future.

I'd like to close my remarks with a quote from my friend Lady Bird Johnson, who has this to say on the last page of her book Wildflowers across America: "Saving our legacy of wildflowers"—and I would add the grasses in which the wildflowers grow—"is something that I am convinced can be accomplished with the right combination of workable ideas and citizens with spirit. How much poorer our world would be without this bounty." And how true that is.

"I think of the words of an old Texas Ranger, written in 1875, 'All of western Texas was a real frontier and for one who loved nature and God's own creation, it was a paradise on earth. In the springtime one could travel for hundreds of miles on a bed of flowers. Sometimes they came up to my stirrups. Oh, how I wish I had the power to describe the wonderful country as I saw it then.'"

Then Mrs. Johnson goes on to say, "For my seven grandchildren and everybody else's, I hope we can keep a part of that vision in our public and private landscapes. In our quest for a better future, I have faith that an appreciation for the values of the past and for the beauty and health of this natural world we all share will be high on our agenda." And I too hope that it is high on our agenda.

One of the things that I hear a lot here in Texas is "We Texans love our land." I've been wondering exactly what that means. So we invited Laura Jackson, who has thought a lot about this question and is also an old friend and colleague from my days at the Desert Botanical Garden, to address us on the subject of what it means to love the land.

Global Warming and the Changing Land

 

My subject today is global warming. Although these two words are used almost daily in the media, most people don’t really know what it is. So I’d like to spend a few minutes defining what we mean by “global warming.”

For the last several years, I've been part of an international organization called the Intergovernmental Panel on Climate Change (IPCC), which was established in 1988 by the United Nations Environmental Programme (UNEP) and the World Meteorological Organization (WMO). The panel was formed at a time when scientists first began to worry that there was some connection between human activities and changes in our climate.

Let me describe the panel a bit more. The IPCC consists of three working groups. Working Group I assesses the scientific aspects of the climate system and climate change, so this group consists of about 200 climate scientists who meet on their own. Working Group II addresses the impact of climate change—that was my group, and there are about 300 of us. Another 200 social scientists make up Working Group III, which assesses options for mitigating climate change. The recent report actually took three years of work, and during that period we were meeting every two or three months, either as small committees or the full working group.

To date, the IPCC has issued three full assessment reports. The most recent of these, the Third Assessment Report, was released in the summer of 2001. The main conclusion of this report—which involved the work of hundreds of experts in meteorology, the cryosphere (ice and snow), glaciology, biology, agriculture, and economics—was twofold: (1) human activities have caused a large increase in what are called greenhouse gases, which I’ll explain in a moment, and (2) this increase in greenhouse gases is most likely responsible for the observed rises in global temperature over the past 50 years.

Now we come to global warming. In general, it means that the average temperature of the globe is warming from one year to the next. But it also means much more than this.

In concrete terms, global warming means that the weather itself is changing and weather patterns are changing. We’re seeing not only a general increase in temperature, but also changes in precipitation patterns over the last 50 to 100 years. For example, rainfall is occurring in fewer but more extreme events. In other words, floods have increased over the past 100 years.

So what is the greenhouse effect that is supposedly causing these changes? Greenhouse gases have actually been around for a long, long time. These gases, such as carbon dioxide, methane, and various nitrogen compounds, occur naturally as by-products of certain geological and biological processes. When they rise into the atmosphere, they build up and form a kind of a blanket.

When solar radiation passes through the atmosphere and strikes the earth’s surface, some of this radiation is absorbed, but much of it is converted into heat. As this radiated energy rises and escapes, it is trapped by a “blanket” of greenhouse gases that absorbs and reflects the heat back toward earth. The effect of this trapped energy is to warm the earth. Without greenhouse gases, the earth would be about 60 degrees Fahrenheit colder than it currently is, and life as we know it would not exist.

The greenhouse effect is a perfectly natural phenomenon that has been taking place for millions of years. The problem has to do with what’s been happening in the last 140 years or so.

These same molecules that make up naturally occurring greenhouse gases—carbon dioxide, methane, nitrous oxide—are likewise produced by the burning of fossil fuels and other human activities. So human beings have been increasing the levels of greenhouse gases in the atmosphere. More of the sun’s heat is retained, warming the surface of the earth and the atmosphere nearest to the earth. So while the greenhouse effect is natural, human beings have strengthened this process in the period between 1860 and the present.

Let’s take a look at carbon dioxide in particular, which is thought to be responsible for most of the warming observed over the past century. Atmospheric concentrations of carbon dioxide have steadily increased from about 290 parts per million in 1860, the beginning of the Industrial Revolution, to a little above 360 parts per million at the current time (Figure 1). That’s about a 30 percent increase in carbon dioxide concentrations.

{insert Figure 1 here}

What is this increase due to? Essentially the Industrial Revolution. Around that time, we began to burn enormous amounts of fossil fuels that had been locked below the surface since the Cretaceous period, when the dinosaurs roamed the earth. Burning these fuels released carbon dioxide into the atmosphere, and with the spread of industrialization around the globe, concentrations of carbon dioxide have steadily increased.

Carbon dioxide lasts about a hundred years—it’s a very stable molecule. Therefore, once it reaches the atmosphere, it hangs around for quite a long time before it breaks down. The burning of fossil fuels—to supply power for our homes, automobiles, and industrial processes—is responsible for about 75 percent of carbon dioxide emissions caused by human activity. The remaining 25 percent is caused by other sorts of human activities, such as deforestation.

When a forest is cut down, trees are removed from the ecosystem and replaced by bare dirt or agricultural crops, which require much less carbon dioxide for photosynthesis than trees do. Thus, deforestation results in less total biomass for storage, so the extra carbon dioxide that is being produced remains in the atmosphere. Deforestation is often accompanied by clearing, especially in many Third World countries. Once the large logs are taken off, the residue is cleared by burning, which releases yet more carbon dioxide.

And the rate of deforestation is increasing. In Brazil, for example, deforestation in was largely confined to the coastal and southern regions in the 1970s; just ten years later, large areas of forest were being cut in the Amazon Basin and this trend has been continuing.

Now, what about temperature? Over the last 140 years, global average temperatures have fluctuated between warmer periods and cooler periods (Figure 2). But if we consider the general trend, it’s clear that the temperature has been steadily climbing. Global average surface temperature has risen by about one degree Fahrenheit over the last century. In most regions of the United States, temperatures have risen by between 1.8 degrees and 5.4 degrees Fahrenheit. In the past 30 or 40 years, this temperature increase matches the increase in carbon dioxide concentration very closely.

{insert Figure 2 here; scale on right is in degrees C; don’t know if label is on chart}

To study temperature trends, scientists analyze data from climate stations around the world. Records are rather sporadic for the years before 1910, although various kinds of historical records can shed light on weather and climate. But since 1920 good meteorological data has become increasingly available—at least from Europe, the United States, and Asia. If we look at the details of this temperature increase, what you see is that 1998 was the hottest year on record. The data show that the 13 warmest years on record have all occurred in the period since 1980, with 1998 the warmest. Indeed, temperatures have increased phenomenally over the last century.

But a lot of people are saying, well, temperature goes up and down; this is just normal variation in climate. So let’s see what we can learn about natural variability by looking at temperature trends that go back 1,000 years.

Of course, there were no meteorological stations then, but scientists are able to estimate temperatures further back in time by using proxies such as tree rings, coral reef growth, which is much like a tree ring, and ice and ocean sediment cores. The use of ice cores involves drilling deep into glaciers where the ice has trapped little bubbles of gas and oxygen isotopes, which can indicate not only exact atmospheric concentrations of carbon dioxide at that time but temperatures as well.

It’s certainly true that the combined data show huge fluctuations in temperature from year to year, warming periods followed by cooling periods, with the pattern repeated again and again until the last 140 years (Figure 3). But these ups and downs are fairly regular and in the same plane until the start of the Industrial Revolution, when temperatures increase sharply and climb to levels much hotter than we’ve seen before.

{insert Figure 3 about here}

If we go back even further, say 160,000 years, the ice core samples again point to major fluctuations in temperature as the earth experienced glacial and interglacial cycles (Figure 4). As the figure shows, large increases is carbon dioxide concentrations have been followed by gradual declines and then subsequent large increases. For thousands of years, this cycle—what we call natural variability—was due to biological and geological processes. However, current carbon dioxide levels are well outside the bounds of natural variability. They are far higher than those of any peak period in the last 160,000 years, and the rate of change in carbon dioxide concentration is also unprecedented. But even more striking is the tight correlation between carbon dioxide concentrations and global temperatures. In the same time period, temperature has risen and fallen but always closely tracking those carbon dioxide levels.

{insert Figure 4 about here}

This is what first gave scientists the idea that temperature was indeed very tightly linked to carbon dioxide concentrations. And since then, the numerous experiments of atmosphere scientists have shown that there is indeed a mechanistic link between carbon dioxide and temperature and that carbon dioxide does effectively act as a blanket.

Now, ice core samples can actually go back 420,000 years. While they show the same kind of cycling, with both carbon dioxide and temperature rising and falling in tandem, at no point in that long period are carbon dioxide levels as high as they are now—about 30 percent higher than they have been in the last half million years or so.

If we go back even further on the timeline, we find small peaks of warming that are hotter than modern temperatures, but we must go back millions of years—to the Cretaceous period and the time of the dinosaurs—before we see evidence of temperatures that were quite a bit hotter than what we are experiencing today. The Cretaceous period was associated with what we would now consider very tropical conditions—very high temperatures, extremely high humidity, lots of rain, and a totally different set of plants and animals. In other words, the world’s climate was fundamentally different from the climate of today.

The last 10,000 years is the period in which human civilization arose and in which we have really flourished as a species. Prior to this, human beings weren’t really very numerous.

In the Cretaceous, when the dinosaurs were king, life was very different. The only mammals that existed were rodent-like creatures. They were our closest relatives. Large mammals like horses, elephants, and lions did not evolve until much later. And the land, of course, was very different. The area that is now Texas was mostly under water, and those ancient oceans deposited all the lovely fossils that are used in our beautiful limestone homes today.

Climate change was actually one of the reasons for the disappearance of the dinosaurs. We hear a lot about a meteor striking the earth as a cause, and that very likely did happen. A large meteor would have spewed out a huge cloud of dust, blocking the sunlight, cooling the earth down, and possibly making it drier.

At the same time, the continents were drifting away from the equator and towards the poles, a move into cooler latitudes. This very gradual climate change, a natural process that was possibly helped along by a meteor crash, is what caused quite a few species of dinosaurs to gradually disappear. They simply were not adapted to a cooler, drier climate.

All modern species of plants and animals are equally adapted to their local climates. This is why you don’t expect to see a Texas armadillo living with an Arctic penguin. The very idea seems pretty silly to us because species are restricted to fairly small regions of the globe, and biogeographers and ecologists have shown that these restrictions are largely due to climate. We call it the climate envelope—the climate that will sustain a particular species.

Now, humans are one of the very few species that occur throughout the globe. In fact, we may be the only one except for certain microorganisms. But we are also adapted to the climate in which we evolved in. In the far north, the tribal peoples have evolved with thick bodies and short limbs to retain the heat. In much hotter climates, the people have darker skin to protect against solar radiation, and they are also generally taller, with longer limbs, so that they can lose heat. In Europe the people are in between those two extremes.

So let’s look at what’s been happening to species over the past century with these increases in temperature. Since species are restricted to a fairly small area by their adaptation to climate, then one result that you would expect to find with climate change is the movement of species from one geographical area to another—in other words, dying out in some parts of their range and expanding in other parts. And that is indeed what we are finding.

Let me start with an example from my own work with butterflies—Edith’s Checkerspot (Euphydryas editha), which occurs in the western United States. This species is a very good candidate for climate-related studies because it has a fairly large range. It extends all the way from Mexico to Canada, encompassing many climate zones, and it is also a species that biologists have been studying for 30 years.

Furthermore, we know from hundreds of small-scale studies that climate really does drive its populations. As part of its natural biology, populations become extinct all the time because of various extreme weather events.

Historically Edith’s Checkerspot has lived in many different habitats, from the coastal meadows of California to the highest mountains in California, Oregon, Washington, and Canada, where its host plants grow. Over the last century, a large number of population extinctions have been observed. Since populations become extinct as part of the natural biology of that species, this alone doesn’t necessarily mean much until we look at the pattern of those extinctions (Figure 5).

{insert Figure 5 about here}

In the southern or lower range, in Mexico and southern California, about 75 percent of the populations have become extinct. In the middle of the range, about 40 percent have become extinct, and in Canada, only 20 percent. It should be emphasized that all the extinctions occurred in natural habitat, so human destruction of habitat was not a factor. This pattern in rate of extinctions has effectively shifted the range of the species northward by about 55 miles on average.

We see the same kind of shift with altitude. In the last hundred years, the populations at the low elevations have become extinct at a fairly high rate—about 40 percent—and in areas where the habitat is intact. In contrast, only 15 percent have become extinct in the high elevations. This means that the butterflies have moved nearly 400 feet up the mountain as well. Interestingly, this shift in range northward and upward matches the shift in temperature that has occurred over the same area. By tracking the temperature isocline—that is, a line on the map connecting areas where mean yearly temperature is the same—scientists have discovered that the mean temperature for, say, June has moved northward by about 63 miles.

Higher temperatures are a problem for the butterflies in the southern area and at lower elevations because the host plants dry up before the caterpillars fully develop. The overall effect of increasing temperatures, then, is to favor the populations at the northern and upper range limits, to the detriment of populations at the southern and lower range limits.

Another species that is undergoing a range shift is the anopheles mosquito, which carries malaria. The anopheles mosquito occurs in Texas, but we’re at its very northern limit, so we really don’t have a problem with malaria in Texas right now. But scientists predict that this mosquito is not only going to spread farther north but also become more abundant in areas where it currently occurs. Warmer conditions encourage the growth of the malarial parasite and the transmission of the disease, so there is likely to be a much higher incidence of malaria in the wild than it is today in Texas. Now, this isn't necessarily a problem for Texans because we have very good mosquito control programs and very good health care. The IPCC working group concerned with health issues—and many of these people came from the Center for Disease Control in Atlanta—concluded that, although malaria in the wild may become more prevalent, the risk of infection will depend on how we manage health care, sanitation, and education initiatives. And the same is true for most developed industrial countries.

Unfortunately, Third World countries currently lack good health care and effective mosquito control programs. So the spread of the mosquito into parts of northern Africa and the likelihood of an increase in malarial transmission is of great concern.

As I mentioned earlier, long-term changes in physical and biological systems as a result of regional increases in temperature have been widely documented (Figure 6). These studies show changes in cryospheric systems, in water flow, in glacial extent, in sea ice, and in the range shifts of plants and animals all over the world—much like that of Edith’s Checkerspot butterfly. These published studies have covered 400 plant and animal species or systems and span the globe reasonably well.

{insert Figure 6 about here}

Of those 400 species and systems, 91 percent of the changes that have been documented are what you would expect from climate change.

For example, the red fox has shifted its range northward by about 150 miles, threatening the Arctic fox. Historically the red fox has occupied much of North America, including Canada, the northern extent of its range. It is not as well adapted to cold conditions as the Arctic fox, which is generally confined to Arctic regions. Apparently the two species cannot coexist. The Arctic fox is much smaller and quite passive whereas the red fox is much more aggressive. As the red fox has expanded farther north over the past century, the Arctic fox has been forced to retreat to a narrow region along the Arctic Ocean.

The changes are not confined to the northern latitudes. A study of bird communities in Costa Rica’s Monte Verde National Preserve revealed similar range shifts. The preserve extends from lowland valleys up to cloud forest in the mountains. Over the past 30 years, the keel-billed Toucan and other tropical birds that live down in the valleys have started moving up the mountain slopes and coming into contact with the birds of the cloud forests. One such bird is the tiny, shy, brilliant green quetzal, which is highly revered in Mayan legend. The males have a tail that can be a long as three feet, which prevents the birds from defending themselves very well. As the toucan invades the mountain habitat, it competes with the quetzal for nesting sites. And since it’s much bigger and much more aggressive, it’s going to win every time. Many of the cloud-forest species have declined or already become extinct with the destruction of habitat, and range shifts increases the pressure on populations even more.

Increases in average temperatures produce changes in physical systems as well. Take glaciers, for example. Glaciers have been photographed and measured for 50 to 100 years, and the historical record demonstrates that snow and ice cover in glacial areas has dramatically decreased around the world. In general, the glaciers of the European Alps have lost 30 to 40 percent of their surface area and about 50 percent of their volume. In Africa, the glaciers on Mount Kenya and Mount Kilimanjaro have lost 60 percent of their area in the last century. In Glacier National Park in Montana, more than 70 percent of the glaciers have already melted, and they will probably disappear by 2030 if warming continues.

The shrinking of glaciers has a significant socioeconomic impact. Many city water systems, for example, are supplied by melting winter snow. In addition, the melting of mountain glaciers contributes to rising sea levels. It is estimated that about 30 percent of the projected change in sea level by 2100 will come from melting glaciers.

Another observed change that is believed to be a response to warming has to do with disruptions in the timing of events. Everyone knows that spring is associated with warmer temperatures, and that’s when the flowers come out. The flowers germinate and bloom, the trees start leafing out, and the butterflies appear.

For several hundred years, people have informally documented when these events occur. To take one example, the Marsham family in England has been recording this information in diaries since the 1700s. For the last 50 years, scientists have kept much more rigorous records of these kinds of observations. We’ve discovered that, over the past century, the events associated with fall and spring are changing by as much as one week to three weeks.

Spring is coming earlier in a very real sense. Migratory birds and butterflies are arriving to their nesting or breeding grounds earlier. Frogs, insects, and birds are breeding up to three weeks earlier. Many plants in Europe and North America are flowering between two and four weeks earlier in the spring. And if you look at the timing of fall events, such as the turning of leaves and the dropping of leaves from the trees, they are occurring later by about one or two weeks. With spring coming earlier and fall later, we’re experiencing an absolute increase in the growing season.

This isn’t necessarily a bad thing, of course, especially in the northern latitudes. An increase in the growing season may allow agriculture in regions where it has always been limited before.

Changes in plant and animal communities are also taking place. Laura was talking about grasslands and native prairies, and in the last 30 to 40 years these areas have undergone a noticeable increase in trees and shrubs. Woody plants have become more abundant, with woodlands starting to encroach into some of the prairies. Again, humans have not caused the change by planting trees. It’s simply been a fairly natural change.

There are some indications that the loss of prairieland is due not only to heavy grazing but also to climate change—that is, changes in precipitation, rainfall, and temperature—and possibly to high levels of carbon dioxide. This last possibility certainly deserves more study. Experiments in environments of artificially increased carbon dioxide indicate that this gas favors woody plants to the detriment of the native remnant prairies.

I’ve been talking about changes that have occurred in the past century, such as higher temperatures or changes in rainfall patterns that are resulting in drought in some areas and more flooding in others.

But what about the future?

For glimpses into the future, we have to rely on computer models. People have heard a lot about these models and the claim that, depending on the model, you can get whatever result you want. But that isn’t quite true, especially for models that work with global averages. The bigger scale, the better the models work.

Let’s look at how several different computer models predict average temperature increases for the United States over the next century (Figure 7). Each line on the chart represents a different model: the UK model, the Canadian model, and so on. We have our own modeling group in Colorado, the National Center for Atmospheric Research. These models are known as the “Hadley model” and “Canadian model.”

{insert Figure 7 about here}

The chart shows annual average changes in surface air temperature that have been observed for the United States between 1860 and 2000, along with projections for the next 100 years. Modeling groups run their analyses by starting with a common point in the historical record--say the year 1910. They then run their model through time, using particular assumptions about the mechanisms underlying the climate system. That is, each model will input a specific effect of each of several known climate-driving factors: such as carbon dioxide, methane, solar orbital changes, or volcanic activity. Each model uses slightly different mixes of these factors as well as slightly different numbers as to how concentrations of these gases will change in the next 100 years. This is one reason they give different results. Then the output of the model from 1910 to present day is compared with the actual climate record. If the model predictions fit the observed climate, then the model is considered to be a good one. Notice that all of the models are pretty good fits to the actual climate records. The differences are mainly in predicted climate from the present day forward 100 years. These differences are partly due to different assumptions as to how much carbon-dioxide emissions will increase (or not) over the next 100 years.

The negative numbers indicate temperatures that are cooler than the average for the period from 1960 to 1990; the positive numbers indicate warmer temperatures. Today, temperatures are a bit warmer than the average, and the past ten years have been warmer than that.

As you see, there is a lot of agreement among the models, and the predictions are fairly consistent for the next 50 years. Then they start to diverge quite a lot. This means that the models are not as good in predicting temperature increases into the second half of the century as they are in the first half.

Now, you often hear in the media that scientists are uncertain about the models, and I want to explain what that means.

The uncertainty refers to the divergence in these different models. The models all predict warming. The uncertainty is whether this warming is going to be as little as two degrees Fahrenheit or as much as eight degrees Fahrenheit. The bottom line—and there is strong consensus on this—is that the United States will see warmer temperatures over the next 100 years.

Let’s talk about Texas and which areas in the state are the most vulnerable to climate change.

People who live in Texas are accustomed to variable weather. Texas experiences fairly extreme temperatures—extreme freezes, extreme heat. Native plants and animals are adapted to this and go dormant during mid-summer and mid-winter, more or less avoiding these extreme temperature conditions.

The effects of droughts and floods are more difficult to adapt to. Changes in precipitation may have a much greater effect on our ecosystems than temperature.

Unfortunately, the models for precipitation change in Texas vary widely. Some say it’s going to be drier, some say wetter. It’s very difficult to predict the future climate of Texas.

But we know for certain that the sea level is going to continue to rise, and predictions range from 4 inches to as much as 35 inches. Because Texas has such a long coastline and so much development along the Gulf, many regions are vulnerable.

Galveston is a case in point. The sea level at Galveston has risen about 25 inches over the past century, due to a combination of the rising level of the ocean and the sinking of the land as groundwater is pumped out to provide drinking water. Furthermore, it’s a very low island, even relative to other barrier islands. Galveston has actually become a hotspot for research scientists because of all these converging factors, and it’s likely to experience some serious problems in the next 20 to 50 years. Similarly, other barrier islands—such as Padre Island, with its wonderful National Seashore recreation area—is going to be highly vulnerable to sea level rises.

Other areas of concern are the tidal flats and salt marshes, like the Aransas Pass National Wildlife Refuge, which is breeding habitat for the whooping crane. The salt marshes also provide a home for oysters and clams as well as the nursery grounds for young shrimp, crab, and fish. So these marshlands not only play an essential role in natural systems but also have economic benefit for commercial fisheries.

Now, you may very well say, if animals and plants change their range and plants change their timing, why won’t the salt marshes just recede? This is a perfectly reasonable expectation, but there are two reasons why the marsh ecosystem can’t migrate inland.

The first is the rate of change. Things are happening very fast, and a single heavy storm can eliminate a lot of habitat for good. The second reason is the extensive development of the surrounding area. There are towns, there are buildings, there are people, not just vacant land where animals and plants can move around. The landscape is very much dominated by humans, and that restricts many of these movements.

Another thing that we know for certain about the future climate of Texas relates to something called the heat index, which is a combination of temperature and humidity that measures the effects on human comfort. For example, in drier air we can cope with the same temperature that would make us very uncomfortable in high humidity.

There is fairly high agreement among the computer models that Texas will experience an increase in the heat index over the next 100 years. This means we will see not only higher temperatures but also higher levels of humidity.

So what can we do about it? Well, I’d argue that the Hill Country will still be the best place in Texas to live—with our cold spring-fed rivers and creeks.

In closing, I’d very much like to thank the Environmental Sciences Institute at the University of Texas for helping me put this fancy presentation together. The extremely helpful graphs used in the slides came from the Union of Concerned Scientists, the U.N. Intergovernmental Panel on Climate Change, the U.S. Environmental Protection Agency, the U.S. Global Change Research Program, the Centers for Disease Control, and several special people. We thank you very much.

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Figure 1. Increases in CO2 concentrations, 1860\-2000. Source: Office of Science and Technology Policy.

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Figure 2. Increases in CO2 concentrations and global average temperatures, 1860\-2000. Source: Office of Science and Technology Policy. 

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Figure 3. Temperature data for the Northern Hemisphere, 1000\-2000. Source: Intergovernmental Panel on Climate Change, Third Assessment Report (2001).

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Figure 4. Correlation between CO2 concentrations and temperature over the past 160,000 years. Source: Office of Science and Technology Policy; Union of Concerned Scientists (talking points).

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Figure 5. Patterns of population extinctions of Edith’s Checkerspot butterfly, 1860\-1996.

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Figure 6. Locations of observed changes in physical and ecological systems. Source: Intergovernmental Panel on Climate Change, Third Assessment Report (2001).

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Figure 7. Projected temperature increases for the United States based on various models, 2000\-2100. Source: U.S. Global Change Research Program.