Compiled by
Zhu Hua Ning and Kamran Abdollahi, Project Directors
Gulf Coast Regional Climate Change Assessment

Southern University and A&M College
&
U.S. Environmental Protection Agency

Contents

• Introduction

• Background on the Gulf Coast Region

• Remarks by Vice President Al Gore

• Keynote Presentation by Dr. John Gibbons

• Gulf Coast Assessment Overview/Charge to the Workshop by Dr. Michael C. MacCraken

• Chapter 1. Wetland, Wildlife Habitat, and Estuaries

• Chapter 2. Farming and Forestry

• Chapter 3. Commerce, Industry, and Energy

• Chapter 4. Health, Water and Air Quality

• Chapter 5. Fisheries and Aquaculture

• Chapter 6. Recreation, Tourism, and Coastal Community Life

• Literature Cited

• Acknowledgement

• Contributors

• Appendix A. Workshop Program

• Appendix B. Preliminary Workshop Report

• Appendix C. Governor Mike Foster's Letter

• Appendix D. Workshop Participant Directory

• Appendix E. Newspaper Clips

This document summarizes the results of the first phase of a major assessment project conducted by the Gulf Coast Regional Climate Change Assessment Steering Committee, led by Southern University and A&M College, and sponsored by the United States Environmental Protection Agency. This project was conducted in collaboration with the United States Global Change Research Program, the National Wetland Research Center, The Science and Engineering Alliance, USDA Forest Service, Louisiana State University, Tulane University and Florida State University. The findings are the result of the Gulf Coast Regional Climate Change Workshop held February 25-27, 1998, which was attended by more than 140 scientists, policy makers, and industrial and non-industrial stakeholders. This document provides an overview of the Gulf Coast regional assessment including the following:

• Identification of current stresses or issues concerning the region;
• Examination of how greater climate variability and climate change interact with the current stresses;
• Discussion of the kinds of information needed to understand and respond to these changes;
• Finding coping mechanisms and strategies that will be most effective in reducing vulnerability and/or enhancing capabilities to adapt to or mitigate the consequences of those changes; and
• Providing suggestions for national-scale research activities that will contribute to regional information needs;

The climate change impact assessment was done on six sectors or issues that are important to the region. These six sectors are:

• Wetland, Wildlife Habitat, and Estuaries;
• Farming and Forestry;
• Commerce, Industry, and Energy;
• Health, Water and Air Quality;
• Fisheries and Aquaculture; and
• Recreation, Tourism, and Coastal Community Life.

The results and recommendations for each of the sectors are presented in six chapters.

The Gulf Coast Region of the United States includes five Gulf Coast States (Texas, Mississippi, Louisiana, Alabama, and Florida) that abut the Gulf of Mexico. The Gulf itself has a surface area of 630,000 square miles, and a watershed area in the United States of 1.81 million square miles. This region is one of the nation's largest ecological systems and is closely linked to a significant portion of the nation's economy. Energy, fisheries, agriculture and tourism rank among the most significant sectors of the Gulf Coast region's economy. The Gulf has five of the nation's top ten fishing ports. Gulf ports handle one half of the nation's import-export tonnage and the Gulf produces 72% of the nation's offshore petroleum production. The Gulf Coast Region relies on many natural resources to fuel important sectors of its economy. Global changes can have profound impacts on the economy and the quality of life for millions of people living in the Gulf Coast region. This report reviews the nature of global environmental change, and addresses the potential health and environmental impacts that may occur in the Gulf Coast region of the United States as consequences of various environmental alterations resulting from global change.

Over the past decades, scientific research has greatly advanced the knowledge and understanding of global environmental change. Research supported by the U. S. Global Research Program (USGRP) and international institutions such as the World Bank and the United Nations Environment Program have demonstrated that human activities exert powerful influences on environmental change on global, regional and local scales (Keeling et al. 1996; Santer et al. 1996). Recent findings by the Intergovernmental Panel on Climate Change (IPCC, 1997) indicate that human activities are increasing the atmospheric concentrations of carbon dioxide and other greenhouse gases (nitrous oxide, methane, chlorofluorocarbons, partially halogenated fluorocarbons, and ozone) which alter radiative balances, and tend to warm the surface of the atmosphere, and in some regions, of aerosols that tend to cool the atmosphere. It is important to note that aerosols do not remain in the atmosphere for long periods and global emissions of their precursors are not projected to increase substantially as compared to the effects of greenhouse gases that are long lived. These changes in greenhouse gases and aerosols constitute key factors in the global and regional changes in temperature, precipitation and other climate variables, resulting in global changes in soil moisture, an increase in global mean sea level, and prospects for more severe extreme high temperature events, floods and droughts in some places. In the United States and elsewhere in the industrialized world, energy use contributes to global warming more than any other human activity. This because most of our energy comes from carbon-based fossil fuels (coal, oil, and natural gas). Fossil fuels provide energy for a variety of purposes, including transporting goods and people, manufacturing products, heating and cooling buildings, lighting spaces, and cooking foods. Each year U.S. energy use releases more than 5.5 billion tons of carbon dioxide into the atmosphere.

Present CO₂ concentrations in the atmosphere are 130% of pre-industrial levels. The surface temperature this century is warmer than any other century since at least 1400 A.D. The temperature has increased by about 0.5 - 1.1° F over the last century and is projected to rise another 2 - 6.5°F by the year 2100. The last two decades have been the warmest in this century. Sea level has risen about 4 to l0 inches and is projected to rise another 6 - 38 inches by the year 2100. Mountain glaciers have retreated worldwide this century.

As greenhouse gases continue to accumulate in the atmosphere, it is expected that an increase in rainfall amount and a consequent increase in river flooding will occur. Recent floods in the Gulf Coast areas (1993, 1997) are examples of such events, and indicate the high sensitivity of flood occurrence to changing climate. Because of its unique location adjacent to the Gulf of Mexico, the Gulf Coast region of the United States is particularly vulnerable to various environmental alterations resulting from climate change.

VICE PRESIDENT AL GORE
Remarks for the Gulf Coast Regional Climate Change Conference

Friday February 27th 1998
(Transcribed from the original video)

I want to welcome you to the Gulf Coast Regional Climate Change Workshop. I am delighted to see that Southern University and A&M College, one of our nation's Historically Black Colleges and Universities, is hosting this workshop. Climate change will have an impact on people all over this country and all over the world regardless of our backgrounds. I hope you will use this workshop to explore the way in which it affects the Gulf Coast region. I welcome all of you to this important forum on climate change.

Just over a year ago, in a meeting with senior federal officials to discuss government research into global warming and related issues, it became clear that we really needed a much better understanding of the regional effects of climate change, the way it affects our people in their communities, and the way it affects our natural resources in different parts of this country. That is the best way to devise solutions to meet this challenge and to protect the lives and the livelihood of Americans from coast to coast and from border to border.

I asked for a series of workshops that would bring together scientists, natural resource managers, business people, and concerned members of the general public, to discuss regional vulnerabilities to climate change and provide regional input into future research plans. It is now just one year later and we have already come a long way. We are midway through a series of twenty successful workshops. This has become an important part of a larger mission and that is the first national assessment of the consequences of climate change for the entire United States of America.

Any objective discussions of climate change must take account of the scientific findings in this area, and the science of climate change is clear and compelling. We know that human activity has been increasing the concentration of greenhouse gases since the industrial revolution. We know that the climate has changed during the same period and that future change is very likely. If we continue with business as usual, sometime in the next century the concentration of carbon dioxide in the atmosphere will be over 700 parts per million. This is a level not seen on the planet Earth for more than fifty million years. The bottom line is that our environment is changing.

We all have a stake in addressing how we can best cope with climate change and its effects. This is one of the most important environmental issues that we face as we enter the 21st century. I believe we can meet this challenge in a way that also stimulates the economy and creates lots of good new jobs, but we need improved understanding, better planning, and new technology in order to do it. That is why we are continuing our strong support for climate change research and focusing it more on regional needs. We are also supporting significant increases in research, development, and deployment of clean energy technologies and more than three billion dollars in tax cuts to encourage new products and technology that will help us clean up the environment and create jobs in the process.

I know that our nation will benefit greatly from your work and I cannot wait to learn about your conclusions. We owe it to ourselves and to our children to protect the atmosphere and slow down the changes that we are presently imposing on the earth and on our children and grandchildren. A new environmental awareness is beginning to emerge. I am convinced that together we can seize that opportunity and build a cleaner and stronger 21st century for all of us.

Thank you for doing your part.

I am pleased to be here with you today. I want to thank Southern University and A&M College, the program committee, and the U.S. Global Change Research Program for all their hard work in organizing this event, and to recognize EPA for their sponsorship. In particular, I want to acknowledge Vice Chancellor Ford, and Professors Ning and Abdollahi for their hard work in organizing this workshop.

Global climate change is perhaps the most pervasive and challenging long-term environmental issue that we face as we enter the 21st century. As we confront this threat to our entire planet's future, one of the things we increasingly realize is that many of its most significant consequences will be witnessed at regional and even local scales, and that the effects of greatest concern will differ from place to place.

Yet, we know less about regional and local consequences for ecosystems and human communities than we do about the workings of the global scale physical climate system. These workshops, and the ongoing dialogue and regional analysis we hope to stimulate, are critical to extend our understanding and to bring knowledge to bear on the management and adaptation strategies that will enable us to cope with a changing climate. That is why I am very pleased that so many different stakeholders are represented here - industry, scientists, environmental groups, and local, regional and national policymakers. Together, we must understand the ramifications of the potential climate disruption, and the options to manage wisely in the face of sobering but uncertain threat.

You will notice I am using the term climate "disruption" as opposed to "change," because I think it is more descriptive of the reality we face. It is the term 2400 scientists used when they wrote to the President about this issue, and it is the term that some of our Nobel Laureates used when they met with the President and the Vice President to discuss the vulnerability of US ecosystems and economic sectors, much as we are gathered here to do over the next several days. The "nature of nature" is that while physical laws do not change, systems and conditions do.

What have we learned about climate?

If we look at the long-term geological record, we can see that tremendous changes have occurred over long periods of time. The Earth has seen very warm periods as well as ice ages over the last 500,000 years. We have recognized big swings in global temperatures, sea level, flora and fauna. Global average temperature swings have often been thought of as slowly occurring phenomena, but there is evidence that significant climate changes have occurred very rapidly in the past. A new ice core from Greenland indicates that a major change in the circulation of North Atlantic currents occurred in about a decade, with dramatic effects on the climate of Western Europe. We simply cannot be comforted that our climate system is buffered against rapid change.

An event of such magnitude has not occurred during the last 10,000 years. The climate has been relatively stable during the period that has seen the development of modern civilization. People from 500 years ago, or even 5000 years ago, would probably notice some differences, but they would recognize today's climate. However, a series of changes has begun to take place over the last century that now drive rates of climate change not seen in thousands of years.

During the past century, the global mean surface temperature increased by almost 1° F. Sea-level has risen by 4 - 10 inches. Glaciers are retreating worldwide. The surface temperature this century is as warm or warmer than any century since at least 1400 AD. The last few decades have been the warmest this century. The year 1997 was the warmest yet recorded, and 9 of the last 11 years were among the warmest years this century. The world is expected to continue to warm, on average, at rates faster than any experienced during the last 10,000 years. So, the climate might not be so recognizable 100 years from now. In fact, if we continue on a "business-as-usual" path, by 2100, the concentrations of carbon dioxide in the atmosphere will be 710 parts per million--levels not seen on the planet for 50 million years. We will have caused this change in a century-a geologic blink of an eye.

Science has done much to illuminate the cause of these changes. The burning of fossil fuels (coal, oil, and gas) for energy is the primary source of CO₂ emissions, accounting for about 85% of US annual totals. Changing land-use patterns through agriculture and deforestation also contribute a significant share. Since pre-industrial times, human activities have added to the natural greenhouse effect by releasing additional greenhouse gases into the atmosphere. For example:

• The atmospheric concentration of carbon dioxide (CO₂) has increased by about 30%;
• Methane concentration has more than doubled; and
• Nitrous oxide concentration has risen by 15%.

Rising levels of greenhouse gases will lead to a variety of global, regional and local effects. Global average temperature will rise with a consequent rise in sea level, due primarily to the thermal expansion of the oceans and the melting and retreating of glaciers.

The Earth's water cycle will intensify, with an overall increase in evaporation so more water is available to fall as precipitation - both rain and snow. Some areas will be threatened by increased flooding, while others will suffer through an increased incidence of drought as continental interiors become warm and dry.

Data taken over the last century show that global precipitation has increased, and this trend also holds for the United States. In the May 1997 issue of Scientific American, Tom Karl reviewed the records of total rainfall and extreme rainfall for the United States over the last century. He reported that precipitation has increased by about 6 percent since the beginning of the century, as has the frequency of heavy downpours. Since the beginning of this century, intense precipitation events--where more than 2 inches of rainfall occurs in one day-have increased by about 20%.

We can clearly see the influence of shorter scale climate variability on the hydrological cycle when we look at the worldwide effects of the periodic changes in Pacific Ocean temperatures and circulation known as the El Niño.

The Gulf Coast region is among the most vulnerable regions in the U.S. to extreme climate events. Over 3,000 square miles of Louisiana, already threatened by subsidence, would be at risk from a 20 inch rise in sea level, as would about 700 square miles of south and west Florida (including a significant portion of the Everglades) and about 1,000 square miles along the rest of the Gulf Coast. Twenty inches is well within the predicted range of sea-level increase by 2100. We must also remember that even if the climate is stabilized by that time, sea level will keep rising for centuries because of the thermal inertia of the ocean.

Last week's tornadoes in central Florida had devastating impact. We know, thanks to the work of Jim O'Brien and his colleagues, that El Niño is associated with a greater incidence of tornadoes in the sea, but a lesser number of hurricanes. The National Oceanic and Atmospheric Administration has noted that the exceptionally strong jet stream caused by El Niño doubtless contributed to the disaster.

A number of other effects of El Niño have manifested themselves in this region and around the country.

Right here in Louisiana it was the wettest January since records began, and North Carolina had the second wettest year on record. In December, January, and February, Tampa, Florida, received 29.95 inches of rain, twice the previous record for these months, which was set in 1936-37. It has been even worse in the West. San Francisco received the equivalent of an entire year's rain in February alone.

Unfortunately, we do not yet fully understand the relationship of climate change and El Niño, but we can say that El Niño events provide compelling examples of the vulnerability of our society to climate extremes. Furthermore, some scientists are beginning to argue that El Niño events may become more frequent in a warmer world. This requires further investigation, but it is interesting to note that the historical cycle of El Niño events seems to have changed during the last several decades, which is a period in which we have also observed significant global warming.

I want to be explicitly clear that we can not attribute any particular weather or climate event to increases in greenhouse gases. We can say however, that global warming increases the likelihood for climate and weather extremes. Recent events all around our nation illustrate the type of consequences that we can expect to experience in a warmer world. So, we all have a stake in addressing climate change and its effects. This is one of the most important environmental issues that faces our planet, our nation, and our communities. There is increasing recognition of this fact.

Most importantly, we have the landmark statement in the Second Assessment Report of the Intergovernmental Panel on Climate Change, published in 1996: "The balance of evidence suggests a discernible human influence on global climate." Furthermore, over the last year we have seen the release of a number of statements about the risks from climate change.

• A group of over 2,500 scientists warned us that we are "disrupting" the climate. They expressed their concern about the impact of further accumulation of greenhouse gasses on future global climate change and the consequent ecological, economic and social disruptions.
• A group of more than 2,400 economists, including six Nobel Laureates, stressed the need for preventive action. They warn that global climate disruption carries with it significant environmental, economic, social and geopolitical risks, and emphasize that there are many potential policies to reduce greenhouse-gas emissions for which the total benefits outweigh the total costs.
• It is not only the science community that is concerned. The Chief Executive of British Petroleum publicly acknowledged the importance of the issue.

While I think that society is beginning to take the climate change issue seriously, I know that the Administration takes it very seriously. So do you. Many of the most significant environmental decisions are made by state, county, and municipal governments, businesses, and individuals. That is where we use energy. Energy drives climate change. Energy efficiency can slow it. Thus, environmental quality depends on the actions of all of us, especially the way we use energy.

The Clinton Administration believes there are a series of prudent actions we must take:

1. We need to deepen our scientific understanding of climate change and its relationships to other stresses.
   • An aggressive U.S. Global Change Research Program must continue to refine our understanding of the physical climate system, and add a new focus on the regional-scale ecological, social, and economic impacts of climate change.
   • As I mentioned earlier, the integrated examination of the multiple stresses affecting regional ecosystems, the analysis of the additional effects of climate change, and the identification of adaptation and management options can inform our decision-making processes.
2. We must stay engaged in the international process of confronting climate change.
   • The U.S. and 160 other nations reached a historic agreement in Kyoto, but additional steps are necessary. We will be working bilaterally and at the next meeting in Buenos Aires will refine this agreement and define further steps.
   • As we look beyond Kyoto, achieving greater participation of the developing world has got to be our top priority. It is clear that the industrialized world is responsible for most of the CO₂ in the atmosphere today, but it is equally clear that most emissions growth is occurring in the developing world. We must find ways for the developing world to grow without unlimited growth in emissions.

   This brings me to the last element of our strategy.

3. We have the opportunity to lead the world in developing and deploying clean technologies for cost-effective reductions in greenhouse gas emissions.

It is important to remember that even a business-as-usual emissions trajectory requires ongoing increases in energy efficiency. Maintaining innovation is not enough to confront the climate challenge; we need to increase it.

To meet this challenge, we are proposing significant increases in research, development, and deployment of clean energy technologies. The President's FY 1999 budget includes a $6.3 billion Climate Change Technology Initiative over five years to reduce U.S. greenhouse gas emissions: $3.6 billion in tax credits for energy-efficient purchases and renewable energy, and $2.7 billion in new research and development spending.

This initiative will help lower emissions, position the U.S. for future economic benefits, and enhance our national security by reducing dependence on foreign energy supplies.

We can develop the clean industries of the future at home or let others reap the benefits. Let me give you a few examples:

1. Although the fuel economy of cars has almost doubled in the last twenty five years, we now travel more than twice as many miles as in 1970. Our Partnership for a New Generation Vehicle (PNGV) has some of the brightest government engineers and scientists working with their private-sector counterparts in the auto industry to develop technologies that will triple the fuel efficiency of today's passenger cars with no decrease in comfort or safety.
2. Productivity improvements in the building industry are lagging far behind all other industries and energy use in buildings accounts for more than one-third of total U.S. emissions. We are pursuing a Partnership for Advancing Technologies in Housing with industry that will make homes cheaper, safer, more efficient, more durable, and more environmentally friendly by developing and implementing new technologies and practices.

All of you here today have stepped up to the challenge of laying the framework for regional assessment of this issue. This is an important step in enabling the Gulf Coast region to understand and cope with the consequences of climate change. But you are also part of a larger process of US National Assessment of the impacts of climate disruption and its consequences. This is the tenth of a series of regional workshops being held around the country. Another ten will take place before the end of the year.

All of these events feed into the National Assessment of Climate Change Impacts which will be issued in 1999. I want to emphasize that I see this assessment as the first in an ongoing series. Climate change is a long-term problem that requires long-term solutions and ongoing assessment is one of the tools that will help us track the effectiveness of our responses. Just like the global challenge, understanding and addressing the regional implications of change requires a sustained effort.

The first element is to identify the complete range of current significant stresses on regional ecosystems, such as population growth, pollution, unsustainable resource use, and existing climate variability. We need to understand the combination of multiple stresses, each with their own effects on the environment, and on each other, if we are to take effective action to preserve and enhance environmental quality and make the transition to sustainable development.

Then we need to look to the future. How are the regional stresses evolving, and how does the addition, or overlay, of climate change on the mixture of stresses affect regional ecosystem, social, and economic sectors? These are complicated, fascinating, and pragmatic questions. How might the Gulf Coast fishing industry, and efforts to preserve freshwater and marine ecosystems, be affected by changes in the amount and pattern of precipitation?

Finally, we need to examine the ways in which we currently cope with such stresses, and to look ahead and identify approaches for coping with predicted future environmental stresses, including climate change. How do the adaptation options for the different sectors I just mentioned fit together? Are they complementary, or are they at cross purposes?

To protect the integrity of our environment and to assure our future national security, we need to make revolutionary--not evolutionary--changes in our energy supply over the coming several decades.

George Bernard Shaw said that "One mark of the educated person is that he/she can be emotionally moved by statistics." Let me share a few of these with you:

• The average US citizen accounts for five tons of emissions per year.
• The average citizen of a developing country accounts for 0.5 tons of emissions per year.
• If the world's population doubles--a change we need to work to prevent--then to keep atmospheric concentrations of greenhouse gases less than twice pre-industrial levels, world citizens cannot emit more than 0.5 tons per person by the end of the next century.

These are daunting challenges!

There is an old Chinese Proverb, "If we do not change direction, we will end up where we are headed" And we are headed toward serious global security, economic, and environmental problems. I believe that all of you gathered here today can provide important input in helping us move to address these problems.

Note: The text is based on the keynote presentation by Dr. John Gibbons, Assistant to the President for Science and Technology, and Director, White House Office of Science and Technology Policies, at the Gulf Coast Climate Change Workshop and Public Forum on February 26, 1998. The text was provided by Susan Bassow, AAA Fellow at the White House Office of Science and Technology Policies.

Michael C. MacCracken,
National Assessment Coordination Office
U. S. Global Change Research Program
Washington DC

Introduction

There are several reasons that the U. S. Global Change Research Program (USGCRP) has initiated the U.S. National Assessment: The Potential Consequences of Climate Variability and Change. The reasons all revolve around answering questions posed in Washington by members of Congress on behalf of their constituents--basically, the questions are:

"So what? So what if the global average temperature warms a couple of degrees? What does that matter to citizens of my district? Of my state? Even of the United States? There are suggestions that we need to sharply reduce use of coal and oil and natural gas to protect the climate--what does this really mean? So what if the climate changes? Can't we just adapt to the changes? After all, people move all the time to warmer climates? So what will climate change really mean to all of us?"

These are really good questions--and they deserve understandable answers. This workshop is part of the process for getting better answers to these "So What" questions.

The Science of Climate Change

These "So What" questions, however, were not the first questions that Congress asked. To understand how they got to these questions, it is useful to review the history of our understanding of the potential for climate change.

About 150 years ago, an English scientist started wondering what happened to all of the carbon generated by burning the coal they were using to drive the Industrial Revolution. Pretty clearly, it went up into the air with the smoke. The smoke particles all came down, coating everything with soot, but where did the rest of the carbon go? While scientists knew at the time that plants could capture CO₂, using the carbon to build their structure and releasing oxygen, that meant the carbon had to show up in trees--so the more they burned, the more trees there would need to be. But everyone was cutting down trees to make sailing ships and the charcoal was needed to make steel and sailing ships. Carbon dioxide could also be taken up by the oceans, but simple equilibrium chemistry indicated that all of the CO₂ would not get sucked up. After all, if that were the case, then why was there any CO₂ in the atmosphere at all? There had to be some fractionation, with some of the CO₂ going into the oceans, and some remaining in the atmosphere. As more and more coal was burned, the CO₂ concentration in the air would clearly have to go up.

There were scattered measurements over the next century, with early hints in the late 1930s that the atmospheric CO₂ concentration was indeed rising. Regular measurements of the concentration in really clean air started in 1957 on a mountaintop in Hawaii. Since that time we have also realized that the bubbles of air trapped in glacial ice can be analyzed to provide a record of the CO₂ concentration before regular monitoring began. From these analyses, a record of the CO₂ concentration has been constructed back now several hundred thousand years (Figure 1).

By the end of the last century, it had also become clear that, like water vapor, the carbon dioxide in the air was an absorber and re-emitter of infrared radiation, creating a greenhouse effect that amplified the warming influence of solar radiation. Much of the physics and thermodynamics of the greenhouse effect can be verified in the laboratory, from satellites, and from observations of other planets. There is no question that the greenhouse gases in the atmosphere--water vapor, CO₂, CH₄, etc.--are keeping the earth significantly warmer than it would be in their absence. The real question is how much the climate will change in response to changes in atmospheric composition.

Based on geological evidence, American scientist T. C. Chamberlain suggested that climate changes in the past might have been caused, at least in part, by variations in the CO₂ concentration. Looking at evidence of past climate changes and their causes has been a major scientific activity ever since. There is now strong evidence this is the case, as seen in the results from the Vostok ice core (Figure 2). Russian scientists have extended the records back in time by using geological and biological evidence to reconstruct the climate and the CO₂ concentration for quite a number of past periods--from the time of the dinosaurs to the present. For all periods, they have found a close association. Quite clearly, nature views the relationship as quite close--providing some lessons we must recognize about what might happen as human activities change the CO₂ concentration.

Just before Chamberlain's suggestion, Swedish scientist Svante Arrhenius made the first estimate of how much the Earth would warm as a result of human activities. He calculated that there would be a warming of several degrees Celsius--roughly 4° to 6° C (about 7° to 11° F)--if the CO₂ concentration were doubled. At the time, Arrhenius thought this would take a very long time to occur for he was simply not able to envisage the rapid increase in emissions that would occur as a result of the spread of the automobile, aircraft, electricity, industry, and population.

Observations have generally borne out these predictions--with a few new twists. As shown in Figure 3, the global temperature record from 1860 to the present shows a warming of about 0.5° C. This warming is occurring quite rapidly in geological terms, and we are now at record warmth for modern civilization.

Adding CO₂ to the atmosphere is not all that human activities are doing to affect the earth system. Agriculture, industrial activities, and other societal activities are also increasing the concentrations of other greenhouse gases. Combustion of coal is leading to the addition of sulfate aerosols to the atmosphere. These small particles create the whitish haze covering and downwind of many industrial regions and they reflect some solar radiation back to space, which tends to cool the climate. Emissions of chlorofluorocarbons have also been contributing to stratospheric ozone depletion. These are not all of the effects, but we believe these are the largest effects at this time. At the same time, nature has not been simply quiet--there have been subtle changes in solar radiation, and there have been very large volcanic eruptions that introduce volcanic aerosols into the stratosphere. These aerosols, like sulfate aerosols, exert a cooling influence. While science has been able to gain some understanding of these effects, there remain uncertainties about precisely how much the changes will be, when they will occur, and what the potential is for surprises.

Identifying the Human Influence on Climate

In that human activities have been changing atmospheric composition for almost 200 years, we can consider the climate record in the context of how human activities are affecting the climate. Model simulations at present yield good agreement with observations if the mutual effects of the increasing concentrations of greenhouse gases and aerosols are considered along with the natural influence of small changes in solar radiation. Figure 4 shows the observed temperature record and a set of model-simulated variations assuming different sensitivities of the climate to a doubling of the CO₂ concentration. The Intergovernmental Panel on Climate Change (IPCC) considers the value of 2.5° C (4.5°F) as its best estimate, which is slightly higher than the value of Arrhenius. However, uncertainties in understanding the climate have kept the IPCC from narrowing the preferred range of 1.5° to 4.5° C (about 2.5° to 8° F) for a doubling of the CO₂ concentration. While most models tend to give results near the central value, it is interesting that most of the evidence from studies of how past climates have varied give a result a bit above the central value. While scientists have not been able to narrow this range for nearly 20 years now, the evidence that the value is within this range keeps mounting.

Examining these results, combining them with studies of the patterns of temperature change, with evidence of rising soil and ocean temperatures, and with evidence of melting glaciers and rising sea level, and rising soil temperatures, the IPCC concluded in 1995 that "the balance of evidence suggests that there is a discernible human influence on the global climate." Some would say, given the amount of evidence, that this is a very conservative conclusion. Others, citing a nearly 20-year satellite record of lower atmosphere temperatures, which some argue shows a slight cooling since 1979, suggest the IPCC conclusion was premature. However, after accounting for volcanic and El Niño influences, the scientists who have generated the satellite record see an underlying warming trend. The longer balloon record of atmospheric temperatures to which they calibrate also shows a warming trend. Because of these results, and recognizing that the satellite record is less than 20 years long, the IPCC authors concluded that the satellite record is not incompatible with their conclusion that the human influence on climate is now becoming larger than the natural variations society has become accustomed to over the past several centuries.

Future Climate Change

If the rise in CO₂ concentration from 280 to about 370 ppmv has caused a warming of about 0.5° C (1° F), what will happen in the future? The IPCC has constructed a range of CO₂ and greenhouse gas emission scenarios for the next century--considering how population, technology, and development will occur. Because it is so hard to predict, they have chosen a very wide range of possibilities, and this is an important cause of why estimates for the future are not, and cannot be, really precise.

Figure 5 shows the projections for the increase in the CO₂ concentration and in temperature, using global climate models and various emissions scenarios. The best estimate for the CO₂ concentration is that it will rise to about 700 ppmv, a level far above levels in recent history and not thought to have occurred on earth in the last 40 to 50 million years. At that time, the earth was much warmer than at present.

Not only will temperatures increase but, because this warming will cause glaciers to melt and water to expand, sea level will rise. In addition, hurricanes may intensify (a recent model result for Pacific typhoons), storm tracks will change, rainfall and runoff patterns will change, and more. While we currently experience a great deal of variability from year-to-year--this El Niño year being a very good example--what appears likely is that the range of variations will occur around new average conditions--creating new extremes, both wet and dry.

National and International Perspectives on Global Change

The first Presidential report on the potential for climate change and its consequences was issued in 1964. The nation had other things on its mind, and the Northern Hemisphere was actually cooling slightly, so there was not much political attention to the issue. During the late 1970s and then throughout the 1980s, there were more and more reports from scientific groups--both nationally from the National Academy of Sciences and from international groups. Politicians were starting to pay attention, and there were a number of hearings before Congress--especially in 1988 when there was a very severe drought in the central U.S. The questions that were being asked almost all focused on whether the climate would really change, whether the predictions could be believed, and how certain was the science.

For most members of Congress and the Administration, the questions have now changed, similarly for nations around the world. At the Rio summit on the Environment in 1992, the nations of the world enacted the Framework Convention on Climate Change. They committed themselves to a very important goal.

"Stabilization of the greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time-frame to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened, and to enable economic development to proceed in a sustainable manner."

With 160 nations now endorsing this goal, the nature of the discussion has changed. For all of the nations, the potential for very significant climate change during the next century has been demonstrated to a sufficient level that policymakers must now seek to understand the risks involved. Questions are now of two distinct types. Questions are about what it would take to do something to prevent the climate from changing--that is to mitigate climate change, and about what climate change will mean if it does occur--that is how to adapt and cope with climate change.

The Potential for Mitigation of Climate Change

If CO₂ was like any other pollutant, some sort of emissions control program would seem to be the cure. However, because coal, oil, and natural gas are mostly made up of carbon, instead of removing some trace amount of pollution, control would require capturing virtually all of the carbon--and that appears to be quite expensive. The only solution seems to be to use less of the coal, oil, and natural gas that are adding CO₂ to the atmosphere.

The IPCC report summarizes a number of calculations of how much fossil fuel emissions must be cut to limit the continuing rise in CO₂ concentrations in the atmosphere. As shown in Figure 6, the cutbacks required are significant.

Last December the developed nations met in Kyoto, Japan and agreed, subject to approval by their governments, that they would start the process of controlling emissions, reducing their emissions of greenhouse gases to several percentage points below their 1990 levels by about 2010. Critics of the agreement abound. On one hand, this agreement will not come close to meeting the stated goal of stopping the increase in concentrations of greenhouse gases as called for in the Climate Convention. On the other hand, critics of the agreement suggest that even this modest reduction in current emissions could be quite expensive. A third view is that technological improvements can make the cost of meeting this agreement quite low--or even beneficial--and so the proposed federal budget has new incentives for technology development.

Whatever view one takes, it is clear that over the coming decades, stabilizing the CO₂ concentration will require significantly more cutbacks in emissions--both by developed and developing nations--than were committed to in the Kyoto agreement. This does not mean that there is no purpose in starting to introduce controls--only that present agreements, hard as they may be to ratify and implement, are only a beginning on the path to stopping climate change. Unless we want to leave very different climate conditions for our grandchildren, emissions cutbacks must start very soon to slow the growth in emissions and then cut them back significantly.

The Need to Cope With Climate Change

If society cannot stop the build-up in greenhouse gases now, society will not be able to stop climate change. Even if society were to cut back global emissions significantly right now, the climate would still continue to change for some decades as a result of past emissions--it takes time for the climate to come to a new equilibrium. Even if emissions were to go to zero so that there were no further changes in the atmospheric concentrations of greenhouse gases, the warming over the next century would be as much as it has been over the past century (albeit only about 20% of what is projected to occur). With emissions continuing, climate change will increase. What is perhaps more worrisome is that sea level rise is projected to continue for centuries as the oceans keep warming and glaciers keep melting.

What is very clear is that we will experience climate change. Recognizing this--and facing objections to cutting back emissions--those in Congress are increasingly asking questions about what climate change will mean:

So what if climate changes? How will climate change affect us? How will it affect the citizens in my district? How will it affect the citizens of my state and region? How will climate change affect the nation and the world? Are the effects of climate change really going to be important given all the other changes that are occurring?

At the global and national levels, some studies of the potential consequences of climate change have given indications of the types of changes that could occur. In that fossil fuels provide tremendous benefit to society, the global focus has been on major categories of changes to aspects of the environment that provide important services to humans. Thus, the types of impacts of most concern focus on potential consequences to human health, food production, water resources, communities in coastal regions, and the many and diverse aspects of potential impacts to forests, wetlands, grasslands, and many other types of ecosystems that provide both products and services to society.

The US National Assessment

Information on the general types of impacts is interesting, but it is not really very helpful in understanding how climate change will affect each one of us or in understanding how we will need to adjust and try to cope with the changes. It is providing more specific answers that is the challenge of our national assessment.

The nation is so complex that no small group--whether of scientists or those in Washington--can just go off and write a simple explanation. Not only would such a select and distant group likely not address the questions that really matter, but no one would believe what was written. The only way to get a good understanding of the climate and the human and societal dimensions of the problem is to initiate an extended dialog on the issues with those who will really feel the changes. These regional workshops are to be the beginning of this dialogue. The US Global Change Research Program is sponsoring a number of regional workshops around the country where the dialogue is getting started.

We have learned several things from the nine workshops that have been held so far. First, we have learned that it helps to identify the key sectors in a region to provide a focus to the thinking about potentially large impacts. Second, it helps to start the discussion around four basic questions:

1. What environmental stresses are now affecting the critical sectors in the region and how might these stresses play out in the future?
2. How might climate amplify or moderate these stresses--or introduce new ones?
3. What further information is needed to more fully answer questions about climate impacts on these and other sectors?
4. What coping actions might help to alleviate the identified stresses, hopefully in a win-win way, so as to avoid the adverse impacts of climate change?

A story from the first workshop in the Central Great Plains might help to clarify how the process has worked at other workshops. Quite a number of ranchers came to that workshop--they were a bit reluctant to do so, in that they are often portrayed as part of the environmental problem. The cattle produce waste that pollutes river waters and methane that exerts a strong warming influence on the climate; their plowing of the soils causes carbon in the soils to oxidize and become CO₂ that also induces warming; and their animal and fertilizer wastes come down the Mississippi and may be causing the lifeless hypoxic zone in the Gulf of Mexico. How much worse can things get? Well, climate change is predicted to make it hotter in the summer, reducing soil moisture, and therefore reducing their crop yields. Furthermore, cutting back fossil fuel emissions would lead to higher fuel prices. It all sounded pretty hopeless.

However, by the end of the workshop, things had turned around. Fossil fuel cutbacks will likely make a market for biomass fuels--so the animal waste becomes a resource that would earn the ranchers money instead of costing them money. Similarly, the methane gas emissions can be a fuel resource. Shifting to no-till agriculture would require less fossil fuel while also helping to enhance carbon build-up in the soils. Not only might this earn ranchers payments for sequestering carbon, but increasing the amount of carbon in the soil helps to increase moisture-holding capacity, making ranchers more resilient not only to climate change, but to the natural variations that bring wet and dry years to the Plains. The ranchers started to see themselves as part of the solution--if they were prepared with the right information.

What happens in the Central Great Plains will affect conditions here on the Gulf Coast. What they do and what the climate does will affect river flow in the Mississippi, and will likely affect erosion rates and silt transport. Maybe the changing rainfall and runoff patterns and their timing will affect the hypoxic zone, or the supply of silt to barrier islands, or nutrients that affect marine life and coastal estuaries.

It is such questions and issues that need to be explored at this workshop. The workshop is being organized as part of the government's research program. We are not into regulations, but are into exploring connections and couplings--helping to provide the information needed to avoid decisions that might lead to adverse impacts from global change. Our assessment is starting with a regional focus--issues relating to where people live. It is also looking at some key sectors on a national level and will be working to try to provide a picture of what the nation's sensitivities and vulnerabilities are to climate change. Our hope is that with information and the involvement of people, organizations, and governments, everyone will be better able to cope with the changes that are coming, and will be able to identify actions that can aid in adaptation to the changes that will be occurring.

Thus, this workshop is really your workshop. We at the federal level are here to be resource people, to ask questions, and to report on lessons from other regions and studies. It is up to you to decide where the discussions go, what issues we explore. To advance the National Assessment process, we are asking that the workshop report on its discussions, and, over the next year, we are asking that the network that emerges from this workshop prepare a summary report for yourselves and for the nation that will at least start to answer the "So What" question that members of Congress are asking and that will tell the rest of the nation why what is happening in your region is important to the rest of the nation.

Closing Comments

Let me close with a brief story. Last summer, we asked Virginia Burkett to speak at a monthly seminar the USGCRP sponsored on Capitol Hill. The topic was coastal wetlands, mainly along the Gulf of Mexico. Virginia gave a wonderful talk, describing how this and that barrier island was disappearing or changing. It was fascinating--but it was not quite connecting to the mostly inside-the-Beltway audience. During the question and answer period, I tried asking a question to help make this connection. I asked: "Well, it is all very interesting that barrier islands are disappearing along the Gulf Coast, but I live in Maryland and why should I care?" There was a very brief pause before there was quite an eruption: "Where do you think your shrimp come from?" "Where do you think the Gulf fish come from?" "These islands help defuse hurricane winds--damage will be much greater without them, and your taxes pay for FEMA reimbursements." "Do you know how many people vacation there?" "The Mississippi is a major shipping channel that supports the nation's economy." And on and on--I just sat quietly taking notes--hearing just what I had hoped would be said. This region matters to the rest of the country, and the world, and impacts here will affect us all.

Since I have become involved with the Steering Committee for this workshop, other issues have started emerging: What will be the distributional effects of these consequences across different income groups--across rural and urban dwellers, and so on? What unique issues arise because New Orleans is below sea level, etc., etc., etc.?

Climate change will be important not only for you, but also for the country, and we want the discussions that begin here to seek to understand what these changes will be, how important they will be, and to start to explore how to plan for the future in ways that will accommodate climate change.

Captions

Figure 1: The atmospheric CO₂ concentration has risen from about 275 ppmv prior to the Industrial Revolution to a level of about 370 ppmv today. This increase has occurred as a result of emissions from fossil fuel combustion, deforestation, and carbon release from soils caused by agriculture.

Figure 2: Record of CO₂ concentration and temperature from the Vostok ice core in Antarctica and extended to the present. There is a close association between the CO₂ and temperature changes, with the variations in CO₂ apparently amplifying temperature changes initiated by cyclic changes in the Earth's orbit around the Sun.

Figure 3: Global temperature record from 1860 to the present, showing a warming of about 0.5° C (1° F) over the last century.

Figure 4: The observed temperature record and climate model simulations incorporating observed and reconstructed changes in greenhouse gases, aerosols, and solar radiation (from Wigley).

Figure 5: IPCC projections out to the year 2100 of the increase in concentration of CO₂ and the consequent increase in global average temperature for various emission scenarios and climate sensitivities.

Figure 6: Stabilizing the concentration of CO₂ in the atmosphere will require significant cutbacks in emissions from projections of the emissions rate assuming Business-as-Usual.

On assignment from the Lawrence Livermore National Laboratory with support from the US Department of Energy.

Current Stresses

The following six major categories of stresses were identified.

1. Sea-level rise and coastal subsidence

    

   The Gulf Coast is a region prone to rapid subsidence of an order of magnitude greater than the Atlantic and Pacific coastal zones. The Governor of Louisiana's representative at the workshop referred to this region as the "Poster Child of Vulnerability". Accelerated sea-level rise of any predicted rate, high or low, will only exacerbate the impacts of the existing rate of sea-level rise on this highly vulnerable coastal region.

2. Altered freshwater and sediment flux

    

   Gulf Coast ecosystems continue to be impacted by stresses of altered watershed dynamics and flood control measures. Changing climate conditions which impact flow regimes in other regions (such as the Upper Mississippi River watershed) are also felt along the Gulf coast. Gulf coast states have experienced an increase in total annual rainfall during this century. This increase is associated with more intense rainfall events, which alter both the timing and delivery of freshwater to coastal wetlands and estuaries. The State Climatologist for Louisiana stated that intense spring rainfall events have doubled in frequency since 1971, while the number of summer events during that period were half as frequent. In addition to these climatic changes, flood control measures and impoundments alter surface water flows and impede the sediment flux that is necessary to sustain the development of river deltas. The extraction of freshwater for municipal purposes, irrigation, and landscape fragmentation in the coastal zone have altered the balance of freshwater and tidal flows. Several Gulf Coast estuaries and wetlands are slated for engineered restoration (e.g. fresh water diversions along the lower Mississippi River and the Everglade's surface water restoration).

3. Saltwater intrusion, agricultural, industrial, and urban runoff

    

   Rising sea-level and deteriorating landforms allow saltwater to intrude further inland and to mix with surface and groundwater supplies. Changing the salinity patterns of Gulf Coast wetlands threatens stability of freshwater ecosystems and survival of two important shellfish resources - oysters and shrimp. Fertilizers, herbicides, and pesticides applied on agricultural crops in watersheds that feed coastal marshes and estuaries also pose a real concern. The cumulative impact of water removal and replacement, whether for municipal or industrial purposes, involves a reduction in water quality and perhaps pollution to downstream wetlands. Urban flood waters that are pumped across levees also introduce significant contaminants of unknown fate into adjoining wetlands.

4. Resource extraction

   Man's activities associated with natural resource utilization and extraction often present a stress on wetlands, wildlife, and estuaries. The following list of renewable and non-renewable natural resources that are important in the Gulf Coast region suggests the multitude of combined stresses that exist. These are not necessarily listed in order of their importance:

   Resources

   Renewable	Non-Renewable
   Fisheries	Oil
   Furbearers	Natural Gas
   Alligators	Peat Mining
   Turtles	Sand
   Waterfowl	Shell
   Forestry	Gravel
   Spanish Moss	Sulfur
   Palmetto	Salt
   Agriculture	Geothermal
   Cattle grazing
   Citrus

    

5. Storms associated with frontal passages and tropical lows

    

   Frontal passages and hurricanes account for most of the acute effects that lead to coastal changes of barrier islands and wetlands. Even relatively mild winter storms create fetch dynamics in coastal bays and estuaries that can cause significant impacts.

6. Exotic Species

   The invasion of non-indigenous species of flora and fauna alter the structure and balance of coastal systems to the exclusion, in some cases, of native species. The loss of habitat for resident wildlife is also of concern. The Gulf Coast spans the transition zone between temperate and sub-tropical climates and species distribution which adds to its biological diversity as a region. The rate of spread of exotic species may be fostered by climate changes and conditions. Some notable exotic species include Melaleuca, Salvinia, water hyacinth, Eurasian millfoil, Brazilian pepper, Chinese tallow tree, gecko, and zebra mussel.

   Many other stressors may be important, but they are not necessarily unique to the Gulf Coast region or apart from the general categories outlined above. Examples include: ultraviolet radiation effects on corals and amphibians, brown and red tide episodes, hypoxia, wetland loss and fragmentation, eutrophication, municipal wastewater disposal, bulkheads, jetties, and riprap structures, levees and impoundments, solid waste storage and contamination, non-point source pollution, recreational activities, atmospheric deposition, brine disposal, and oil spills.

   Multiple stressors are an issue in the Gulf Coast region, the importance of which may differ somewhat between watersheds and estuaries and with the time of year or episode. The cumulative impacts of all stressors and the realization that interactions between these stressors may also be important.

Critical Information Needs

Critical information needs are associated with an effective assessment of the consequences of climate change and variability for the Gulf Coast region.

1. Information on meteorological changes
   • More information describing past changes, variability and trends in climate is needed. This includes improved geographic resolution using both direct and inferred data such as pollen in sediments and tree-ring analysis.
   • The monitoring network of hydrologic and climatic stations in the coastal zone should be enlarged.
   • Detailed regional and subregional climate models for the Gulf Coast with finer time scales are needed. These models should give us a better understanding of direction and magnitude of climatic variation and intra- and inter-annual extremes, and a better understanding of seasonal shifts, cold front passages, tropical storms, and tidal variation.
2. Information on environmental changes

   First, we need a better understanding of what we have (i.e. the baseline). Second, we need to understand what the Gulf region stands to gain and lose given the predicted change scenarios. This information includes:

   • Documentation and integration of existing data for assessment and monitoring of:
     • Baseline information on species distributions, life history, trends in abundance and distribution, land use, landscape patterns and alterations, natural processes governing wetlands, fluvial systems and geomorphology;
     • Archival preservation of natural history museum collections historic photos and maps;
     • Precise elevation surveys tied to existing benchmarks for the entire Gulf Coast with improved accuracy, to produce contours within centimeters, possibly using remote sensing. Re-benchmarking may be required in those areas where subsidence has occurred;
     • Regional water quality monitoring and reporting;
     • Examination of changes in sediment budgets; and
     • GIS support to integrate information for resource managers.

      

   • Development of climate change scenarios for wetlands, wildlife, and estuaries including:
     • Models of plant and animal community response to estimate or predict:
       • Change scenarios for 50 and 100 year time scales for the region;
       • Impacts on productivity;
       • How will climate change magnify (or moderate) existing stressors;
       • The occurrence and effects of catastrophic events;
       • Changes in the hydrologic characteristics (saline/fresh water interface) and sediment budgets; and
       • Wetlands, estuaries, and/or barrier islands may be created or lost.
     • Models of species response to changes in physical processes including:
       • Native specie's response to climatic shifts and extreme events; and
       • Interactions of stresses, such as exotics, on indigenous species with climatic shifts and changes in perturbation regime/extreme events.
3. Information on socioeconomic and human dimensions changes including an understanding of how climate change and variability are likely to affect human quality of life. Then we need to know how sociological forces will impact wetlands, wildlife and estuaries, with and without changes in climate. These will be based on the following:
   • Changes affecting the landscape's capacity to support human activity:
     • Loss of wetland functions such as water quality, storm buffering capacity, sediment and flood water restoration;
     • Availability and acquisition of potable water as wetlands and other barriers to saltwater intrusion are lost;
     • Risk assessments relative to coastal hazards; and
     • Waste disposal implications.
   • Understanding the sociological driving functions:
     • Demographic projections for the coastal zone;
     • Improved models of how people interact with landscape and environment;
     • Research is needed to obtain information describing public attitudes; and
     • Evaluations and information regarding future jobs for people who are dependent upon coastal resources (non-renewable, renewable, and non-consumptive).

Potential Coping Strategies

Coping strategies should be associated with supporting human well-being in the region and should be associated with the preservation or maintenance of our natural heritage. The strategies include:

1. Human dimensions needs:
   • Innovation and change in public mindset, mainly through education;
   • Incentives to participate in programs that will help coastal residents cope with change will involve:
     • Innovative use of programs such as FEMA buyouts, fishermen's disaster relief, and insurance;
     • Job training programs with an emphasis on jobs that are sustainable within the landscape; and
     • A "GI Bill" for civilian education so individuals can better adapt to changes.
   • Removal of institutional impediments to dealing with change, with emphasis placed on gradual nature of change, rather than radical departure from the traditional basis for coastal living.
2. Natural heritage needs:
   • Increased funding allocations for wetland preservation and restoration; and
   • A strategy for identifying new public land acquisitions to replace reduced and degraded public lands along the coast

Current Stresses

The Gulf Coast Region and the Southeastern U.S. are perhaps the most productive agricultural and forest related areas in the nation. However, current stresses on agriculture and forestry in the Gulf Coast Region are numerous.

• Climate variability is already a prime stress and is related to the many summer storms of both sub-tropical and convection driven origin.
  • Forestry and farming are affected by numerous thunderstorms of high intensity as well as tropical storms and the associated high winds.
  • The high rainfall during short periods associated with these storms leads to flooding and waterlogged soils. Plant growth and animal care are impacted. Reduced root growth and increased incidence of windthrow or crop lodging are not uncommon problems.
• Along the coast and for some distance inland, sea-level rise is a major problem in states like Louisiana.
  • Natural sea-level rise is a product of warming temperatures and thermal expansion.
  • Apparent sea-level rise is aggravated by subsidence caused from the organic soils and the losses of sediment influx as drainage patterns have been altered for human use in coastal areas. Sea-level rise exacerbates drainage of rivers and streams resulting in flooding and saltwater intrusion that severely alter the coastal ecosystems.
  • Freshwater swamps are being killed by saltwater intrusion and bottomland hardwoods are being killed by alteration of flood timing and duration.
  • Farmland use in the coastal areas is also altered by these factors.
• Changes in species composition, changes in wetland boundaries, and complete loss of terrestrial ecosystems to open water areas have occurred. Such changes have also been associated with increased numbers of pests and success of new pests in the region.
• Although high rainfall is common, the Gulf Coast Region also experiences its share of droughts. Droughts in recent years have caused much damage and loss of productivity.
  • Plants growing in waterlogged soils have restricted root systems and once the soils begin to dry out, plants are unable to extract sufficient water from the soil.
  • Wildland ecosystems under water stress often lead to insect and disease infestations, with a concomitant increase in the frequency and severity of wildfires. The release of sequestered carbon through uncontrolled wildfire can lead to major air pollution and to the buildup of radiatively important gases and particles in the atmosphere.
  • The extreme variability in rainfall duration, intensity and location can lead to flooding and waterlogged soils in one area and drought conditions short distances away.
  • In the summer, high temperatures provide additional stress through increased plant respiration, reduced photosynthesis, and direct-heat-caused injury.
  • In the winter, temperature fluctuation and the sudden onset of freezing temperatures result in biological miscues and loss of productivity. The negative impacts on flower and fruit production are most noticeable.
  • Ozone and other air pollutants are a problem in many areas of the Gulf Coast Region. Foliar damage, reductions in photosynthesis, and associated reductions in growth have been shown to occur. This problem is becoming more serious in the Gulf Coastal Region.
  • Increased temperature could cause increases in release of precursors to ozone (e.g., phenolics and terpene reactive compounds).
  • Increases in CO₂ could lead to reduced stomatal conductance and lessen the effects of ozone.

• Perhaps the most anticipated beneficial effect of climate change on farming and forestry is the increased CO₂ levels.
  • The initial impacts of carbon dioxide increases will be enhanced crop and forest productivity. More efficient production on nitrogen limited soils may be an added benefit;
  • Much of the anticipated beneficial effect may be offset by other factors related to climate change. Several unknown and unstudied effects of climate change may alter our perception of the benefits and losses as a result of climate change in the Gulf Coast Region;
  • Normally seen as a positive effect on photosynthesis and plant biomass, the increasing carbon dioxide content of the atmosphere may alter carbon allocation patterns;
  • Shifts in allocation from stemwood to branches or root systems may alter the way a tree handles sudden changes in the environment and could lead to a severe blow to the timber industry; and
  • Carbon allocation related to fruit and grain production versus vegetative and root growth may appear positive until sudden onset of drought conditions finds the crops with inadequate root systems.

We do not know the relative biological costs of these changes given the projected increased variability in climate. Higher C:N ratios in litter may reduce decay and nutrient turnover rates offsetting the increased temperature effects. Shortages of some nutrients are likely to be increased if more rapid growth results from increasing CO₂ levels. Carbon and nutrients could also be sequestered at different rates in woody plant biomass. Crop residues may breakdown more quickly affecting succession and again altering nutrient cycling. These changes may be prominent because of the timing of nutrient turnover. Effects on flowering and fruiting could result from changes in the way nutrients are mobilized both in the plant and in the soil. Again, the potential effects are largely unknown, especially for natural forest ecosystems.

Differential effects for C⁴ versus C³ plants will exist. In farming this may change the relative productivity and economic situation for crop plant selection. In the natural environment relative productivity differences could affect competition and succession. There is some evidence to suggest that species diversity may be reduced in some areas. Long periods of hot weather, day and night, at times may lead to increases in evapotranspiration. Without increases in precipitation, drought effects could reduce plant growth. Higher respiration rates resulting from even higher temperatures could reduce net photosynthesis during the summers. Short winters with highly variable winter temperatures could lead to physiological miscues. Frost damage could occur in some areas and poor pollination and fruiting may result. If miscues are not severe, warmer winter temperatures can mean extended growing seasons and more carbon sequestration. However, changes in wood quality in trees seem probable since season timing differs. The importance of dormant season length in perennials is relatively unknown. Higher rainfall in the Gulf Coast Region will aggravate the high soil water conditions already prevalent. Reduced root growth or increased incidence of root pathogens will subject far greater numbers of plants to increased windthrow and death. Reduced overall growth and increased susceptibility to disease will likely follow on newly affected areas.

Additional interacting factors include:

• The impact of stress on micro-organisms from an ecological point of view;
• Continued expansion of the urban environments causing the demise of agricultural lands;
• Encroachment of urbanization on watersheds and coastal water systems;
• Expansion of agricultural lands in new areas due to changes in climate;
• Erosion and decreased water quality from increased pollution including fertilizers and herbicides;
• Increased demands for agricultural and forest products;
• Increased pressure on recreational lands; and
• Homes are long-term sequestration sites for carbon (increase with population) but may replace forested sites.

Critical Information Needs

• Information needs about meteorological changes

  We need to:

  • Understand the potential arctic outbreak frequency (extremes are of critical importance) e.g., ice storms;
  • Know the how potential productivity of soils will change with climate changes;
  • Understand how the magnitude of change in weather is important in determining effects on agricultural plants and animals;
  • Predict the magnitude of extremes in weather and climate conditions;
  • Provide tools for evaluating the probability of drought occurrence and the duration of droughts in local areas and improve the accuracy of the predictions, especially during the growing season;
  • Develop improved methods for predicting when the minimum conditions for planting will occur (last date of frost, etc.) and the length of growing season;
  • Assess the likelihood of climatic conditions requiring planting of alternative crops;
  • Improve projections of fire severity based on long-range forecasts;
  • Know how far in advance we will have to react to climate change in order to avert catastrophic die-offs or significant losses; and
  • Know whether we are prepared to mitigate the effects of disastrous meteorological events.
• Information needs concerning environmental change

  Many environmental factors associated with climate will also change. We need to understand:

  • Which cultural practices will ameliorate the effect of environmental factors on seed production and agricultural and forest production in general;
  • The environmental impacts on insect and other pathogens;
  • Biotic factors above and below ground (insects, disease, micro- and macro-organisms) and how they will be affected by changes in climate associated environmental factors such as soil moisture, shorter periods of frozen soils, degree of cloudiness, and flood periodicity.
  • The effects of altered hydroperiods and/or drought periods on agricultural and forestlands with different local site conditions;
  • The effects of climate change on migration patterns and general wildlife habitat use;
  • How environmental factors affect soil conservation efforts and water quality considerations;
  • The potential impacts of environmental factors on production of ozone and other pollutants;
  • How key changes in environmental factors interact with genetic adaptation;
  • What how know about changes in the environment that will help to develop new pesticides; and
  • Effects of environment on rates of maturation and metabolism which in turn would affect productivity.

   

• Information Needs About Socioeconomic and Human Dimensions

   

  Changes in population size, demographics, and human life styles will all interact with and influence the effects of climate change. Information needs related to these factors include determination of:

  • Effects of land-use changes on environmental factors at various scales from the local to the global scale;
  • How shifts in population and demographics will be related to climate change (e.g., South to North movement);
  • How alternative life styles as a result of climate change are likely to affect the demands on forest and agricultural resources;
  • The costs associated with the use of alternative energy sources;
  • How petroleum cost increases will affect the agriculture and forestry communities;
  • How incentives would change the rate of carbon fuel use;
  • Types of education needed to influence the consumption of petroleum and improve efficiency of agricultural and forestry production;
  • How climate change might cause geographical shifts of agricultural or forestry operations;
  • Willingness of people to relocate based on changes in climate and production trends in agriculture and forestry;
  • The effects of climate and economic factors on stability in production;
  • How climate change will affect public health and safety;
  • Effects of tighter controls on industrial emissions production and improved transportation systems ; and
  • The implications for agro-forestry

   

Potential Coping Strategies

Many coping strategies are available to modify the effects of climate change and to alter the degree of climate change based on today's knowledge of these relationships. Potential coping strategies for forestry and farming include:

• Reforestation;
• Afforestation and urban planting to increase carbon sequestration;
• Use of specific cultural practices;
• Proper species selection;
• Use of Best Management Practices for sustainability and environmental protection;
• Reducing erosion;
• Maintaining water quality;
• Promoting efficient urban forestry;
• Correct placement of urban trees for energy conservation and low maintenance;
• Sustainability of forestry and agricultural vegetative cover for carbon sequestration and energy conservation;
• Appropriate and energy efficient recycling;
• Agro-Forestry;
• Education and technology transfer;
• Encourage energy efficient practices;
• Use of no till/minimum till agriculture;
• Targeted application of chemicals and pesticides;
• Diversification of crops;
• Development of decision making tools to aid in choosing the correct cultural practices and energy efficient methods for implementation;
• Development of risk assessment tools to predict the impact of global change on ecosystems;
• Research on taxonomy and systematics should be stressed to add to the data base for biological species; and
• Development of Geographic Information System databases to provide key climatic information relative to farming and forestry practices.

Research Needs

The answers and even some of the questions related to the effects of global climate change on the Gulf Coast Region will require research in many areas. In farming and forestry, important research questions include:

• How does carbon sequestration vary for different species (tradeoffs)?
• What are the genetic effects and how much adaptation will be required of specific species under different climate change scenarios?
• What are the relative competitive advantages of various species under different climate adaptation scenarios?
• What are the direct and indirect impacts of environmental factors (e.g., drought, flooding, nutrient deficiency, etc.) on above and below ground plant eco-physiological responses and how do cultural practices affect these relationships?
• What are the important linkages between cultural practices, climate variation, and the water cycle at different scales of measurement ( tree and stand water flux; water budgets)?
• How can we achieve the appropriate balance between natural regeneration/artificial regeneration and silvicultural practices to efficiently use fossil fuels?
• What are the potential impacts of fire, insects and disease on long-term carbon sequestration?
• How are insects and disease organisms and their hosts altered by climatic change? What are the potential ramifications of these changes on the forest and agricultural productivity and on the health of natural forest ecosystems (including forest biodiversity)?
• How will fire, weather, and the resulting fires impact ecosystem health and succession?
• Can we develop alternative energy sources and more efficient ways of using energy for farming and forestry operations?
• What improvements in modeling methods can be made for connecting agricultural and forestry practices to changing climatic conditions?
• What new technologies can be developed to preserve soil quality and sustain agricultural productivity?

Current Stresses

Industries of the region can be divided into two broad categories: primary industries and support industries. Primary industries with the most impact on the economies of the Gulf Coast region (in no particular order) are oil and gas, agriculture and forestry, tourism and entertainment, fisheries and aquaculture, chemical, manufacturing, port transfer and shipping. A number of support industries with important roles in the region (in no particular order) are insurance, finance, real estate, construction, medical and health, public sectors, military, government, and retail.

Current climatic and non-climatic stresses can be related to the relevant industries. Some of these influences originate within the region, while others have global dynamics. Some general "stresses" are coastal land loss, saltwater intrusion, population growth, and education/training of the general population and available workforce. Specific effects on the primary industries include the following:

• Oil and gas:

   

  Clearly, global energy markets, international emissions agreements, and national policy are major forces in shaping the demand for oil and gas products, and the ultimate mix of fuels used to meet the nation's energy needs. Also, the current age and inefficiency of capital equipment is one important stress in this industry as well as in the chemical and manufacturing industries. Weather plays a substantial role in determining demand for, hence the price of, various fuels. Another major stress on the oil and gas industries is the frequency and magnitude of major storms. In such cases, drilling activities in the Gulf are curtailed. While this stress is currently thought to play only a minor role, future increases in storm intensity and frequency associated with climatic change could be important.

• Agriculture and forestry:

   

  Agriculture is particularly sensitive to climate variability and extremes. The dates of the first and last frosts dictate planting and harvesting schedules. Shifts in the length of growing season can benefit or harm agriculture. Some crops will likely benefit from the enhanced CO₂ and increased air temperatures. There may even be opportunities for double cropping (i.e., two growing seasons each year). The expected drying of the soil and increased magnitude of heavy precipitation events, on the other hand, may be damaging to the agricultural industry.

• Tourism and entertainment:

   

  Weather in the gulf coast region has an important influence on tourism. For instance, it is generally known that the month of August can be quite hot and humid, discouraging tourism and encouraging residents to travel out of the region. The role of weather in tourism, however, is a two-way street. Many of the tourists visiting the region in winter months are from the northeast. If winters in the northeast are less severe, there will be less incentive for these individuals to flee to the south. Another important influence on tourism is the perception of health threats. One example is the recent outbreak of encephalitis in central Florida, that resulted in the evening closings of the Disneyworld parks. Even very small outbreaks of infectious disease can have major impacts on tourism.

• Fisheries and aquaculture:

   

  Wetland loss is a current issue of great importance to the fisheries and aquaculture industries. If natural subsidence is enhanced by sea-level rise, these industries may be severely impacted. There are also salinity issues associated with the interface between the coastal salt water and the brackish and fresh water marshes.

• Chemical:

   

  While the chemical industry is generally not significantly impacted by climate, it relies on the oil and gas industries for much of its raw materials, and is also subject to the policy actions of local governments which often act to limit emissions. Environmental activism is also playing a more pronounced role, as the activist groups grow and become more vocal about their environmental concerns. Vocal public opposition to the proposed Shintech PVC plastics plant in Louisiana was cited as one example.

• Port transfer and shipping:

   

  This industry depends upon port access which in some cases may be affected by river flow rates, sedimentation, and the need for dredging. Ship traffic can also be significantly impacted by severe storms.

Critical Information Needs

• Information needs about meteorological changes

   

  We need information on relevant climate variables as well as several secondary variables derived from the primary climate variables. These include statistics on temperature, precipitation, wind, humidity, sea level, cloud cover, atmospheric turbidity, and river flow. An additional parameter of importance is the frequency and magnitude of extreme events such as severe storms, hurricanes, and droughts. The need for information on these parameters was derived directly from the earlier discussion of current climatic stresses on the Gulf Coast industries.

• Information needs about environmental changes

   

  Important environmental changes which may be related to and impacted by climate change include the ongoing subsidence in coastal Louisiana, penetration of high salinity water to inland marshes and estuaries, and changes in coastal habitats. The flow rates of major rivers (such as the Mississippi) and the pollutant levels in these rivers are also an important input into the economies of the Gulf Coast region. We need to know how large scale changes in these environmental variables might affect the local industries directly and indirectly through impacts on ecosystems and biodiversity.

• Information needs about the socioeconomic and human dimension

   

  Aside from environmental and climate changes, there are likely to be many changes in the social, economic, and political parameters that may be just as significant to these industries. Certainly, projections of population demographics for the region will be important. The relative wealth, age, skill, social, and political views of the population will also be important. How will government react? Will it act to protect coastal areas? Will it restrict new development, or the rebuilding process after a major hurricane? Of equal importance is the question of how people will react. How receptive will the public be to information about likely future climate and/or environmental change? This question may be partially addressed by cultural theory which seeks to divide the population into distinct groupings with somewhat predictable behavior. One approach is to use a carefully crafted questionnaire and interview process to partition people into one of four categories: egalitarian, individualist, hierarch, and fatalist. When a particular region is faced with a new issue, understanding the cultural group populations in that region may aid in assessing how the population will respond to the various options.

Potential Coping Strategies

Education and communication are perhaps the greatest barriers to coping with climate change. Without education at all levels, there will not be sufficient support in the near future for changes in the status quo that may help the Gulf Coast prepare for and cope with climate change.

One key issue is that future residential, industrial, and infrastructure development should be limited in regions which are most subject to being inundated as the sea level rises. We should also work to make the region less dependent upon industries which are highly sensitive to climatic change.

There are many existing technologies that can help the gulf coast region become more energy efficient. Louisiana and Texas are among the most energy intensive states in the country due to their large industrial base. There are significant subsidies in Louisiana for industrial energy use. That infrastructure is out of date and inefficient. By reducing energy subsidies it is believed that these industries could be encouraged to modernize their technologies, resulting in much more energy efficient and less environmentally disruptive processes.

Current Stresses

The Gulf Coast shares a number of stresses that are currently creating problems for coastal areas around the country due to a high rate of population influx and development. Many of the health stresses in the region relate to contamination of the marine environment as a result of development, agriculture (nitrogen flow), and industrial pollution, such as benzene and other organic chemicals from oil refining. This is of particular concern because the Gulf Coast has the highest concentration of petrochemical companies in the nation. The addition of nitrogen to aquatic and coastal waters can encourage the growth of harmful algae, while various forms of pollutants can intrude into the water supply or can impact on local air quality.

• Human health

  Table 1 shows some of the current diseases of concern in this region. This table illustrates how vector-borne diseases (carried by a host animal or insect) are linked to ecological conditions as well as socio-economic issues. Although not listed on this chart, there has also been an upsurge in tuberculosis in the Gulf Coast region, a disease transmitted person-to-person.

In addition, there were a number of disease events in Florida in 1997 which affected both humans and plants. These included St. Louis encephalitis around Orlando and three crop pests: the Mediterranean fruit fly in Dade county, citrus canker, and tomato leaf virus carried by whiteflies.

• Water quality

  Diversion of water to serve the growth of the human population in large cities is a potential threat to the availability of clean water in the Gulf Coast region. The large population growth in Atlanta is currently threatening Gulf Coast water quality. Similarly, population growth and the diversion of water is also threatening the water quality of the Rio Grande River. To assess this problem, it is important to monitor key water systems and to determine the purpose for which water is being used.

  Pollutants in water is a major problem in the region. The highest concentration of petrochemical companies in the nation is in the Gulf Coast. With the potential for a rise in sea level, health is threatened by the petro-chemical plants which are located along waterways. In addition to the chemicals released by the petrochemical companies, the Mississippi River carries the chemical pollutants of the central U.S. to the Gulf Coast region. Extraction, refining, and transport of oil and petro-chemicals all carry risks for the health of humans, wildlife and ecosystems. Extreme rains and flooding can enhance run-off of nutrients, pollutants and micro-organics. Heavy rains and high nutrient levels can increase algal blooms and add to the "hypoxic zone" in the Gulf of Mexico, currently the size of New Jersey.

  Salinity of water is a major problem in the Gulf Coast region because it contributes to the loss of oysters. Oysters have a positive effect on water quality by filtering water and removing pollutants. Salinity also increases the difficulty of the water treatment process. Salinity may make the treatment of water more costly and add to the problems of communities which face water treatment problems.

  E. coli in water is a sign of human and animal pollution, and it is often linked to poor municipal processing of sewage. This can be exacerbated by a poor tax base. That often determines how well the water is treated.

  Pond aquaculture is a potential danger to human health because the water used in aquaculture goes directly back into the U.S. water system. There is no ingress or egress in these ponds. Many antibiotics maybe put into the pond and bacteria which are resistant to different antibiotics can multiply. These resistant bacteria are then often released into the environment. It is important to keep the pond water away from estuaries so that new diseases, bacteria, or other health risks for animals and humans are not released into the environment. In addition, shrimp and fish in such confined ponds often become susceptible to disease. As a result, such systems may not be sustainable over long periods of time.

• Air quality

  The growth of major cities and the effects of this growth on air quality is a major health concern in the Gulf Coast region. Large cities such as Houston, Atlanta, and New Orleans have major problems with air pollution, particularly tropospheric ozone (O₃). Pollution stagnation, such as occurred in Baton Rouge in 1990 and 1995, is dangerous and may be exacerbated by increased temperatures. Poor air quality contributes to health problems such as heat shock, asthma, respiratory disease, and allergies.

  When air quality is bad, people often stay inside houses. The air quality there is usually worse than outside. In addition, when temperatures increase, more people use air conditioners, adding to the pollution problems.

Possible Consequences of Climate Variability and Change

• Human health
  • There are potential positive and negative effects on health which could result from climate change (Tables 2 and 3). One example of a positive effect is that higher temperatures may cause some parasites to decrease (e.g., Schistosoma). Each issue in health must be considered on a case-by-case basis. Health issues must then be considered using a cascade approach which focuses on the compound effects on health of many different factors.
  • Climate change through warming may intensify the cascade effect by disruption of species-developed synchron