Sustainable Agriculture And The Environment

Perspectives On Growth And Constraints

Vernon W Ruttan

• Publisher: CRC Press
• Year: 2019
• Print ISBN:
  9780367304744
  9780367289287
• Edition: 1
• eBook ISBN:
  9781000313697
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

This book explores the resource and environmental constraints on sustainable growth in agricultural production into the middle of the twenty-first century. It presents contemporary concerns with the implications of natural resource availability and environmental change.

PART ONE
Introduction

1
Concerns About Resources and the Environment

Vernon W. Ruttan

In this book a group of leading agricultural and social scientists explore the resource and environmental constraints on sustainable growth in agricultural production into the middle of the twenty-first century. Contemporary concerns with the implications of natural resource availability and environmental change are presented in this section to provide the broader historical context.

We are now in the midst of the third wave of social concern since World War II with the implications of natural resource availability and environmental change for the sustainability of improvements in human well-being.

The first wave, in the late 1940s and early 1950s, focused primarily on the quantitative relations between resource availability and economic growth--the adequacy of land, water, energy, and other natural resources to sustain growth. The reports of the U.S. President's Water Resources Policy Commission (1950) and the U.S. President's Materials Policy Commission (1952) were landmarks of the early postwar resource assessment studies generated by this first wave of concern. The primary response was technical change. In retrospect, it appears that a stretch of high prices has not yet failed to induce the new knowledge and new technologies needed to locate new deposits, promote substitution, and enhance productivity. If the Materials Policy Commission were writing today, it would undoubtedly have to conclude that there has been abundant evidence of the nonevident becoming the evident; the expensive, cheap; and the inaccessible, accessible (Ausubel and Sladovich, 1989; Barnett and Morse, 1963).

The second wave of concern occurred in the late 1960s and early 1970s. The earlier concern with potential "limits to growth" imposed by natural resource scarcity was supplemented by concern with the capacity of the environment to assimilate the multiple forms of pollution generated by growth. An intense conflict was emerging between two major sources of demand for environmental services. The first was the rising demand for environmental assimilations of residuals derived from growth in commodity production and consumption (e.g. asbestos in our insulation, pesticides in our food, smog in the air, and radioactive wastes in the biosphere). The second was the rapid growth in per capita income and high income elasticity of demand for such environmental services as access to natural environments and freedom from pollution and congestion (Ruttan, 1971). The response to these concerns-still incomplete~was the organization of local institutions designed to force individual firms and other organizations to bear the costs rising from the externalities generated by commodity production.

Since the mid-1980s, these two earlier concerns have been supplemented by a third. The newer concerns center on the implications for environmental quality, food production, and human health of a series of environmental changes that are occurring on a transnational scale: issues such as global wanning, ozone depletion, acid rain, and others (Committee on Global Change, 1990; Committee on Science, Engineering, and Public Policy, 1991). The institutional innovations needed to respond to these concerns will be more difficult to design. Like the sources of change, they will need to be transnational or international. Experience with attempts to design incentive-compatible transnational regimes, such as the Law of the Sea Convention or even the somewhat more successful Montreal Protocol on reduction of CFC emissions, suggests that the difficulty of resolving free rider and distributional equity issues imposes a severe constraint on how rapidly the efforts of transnational regimes to resolve these new environmental concerns can be put in place (Dorfman, 1991).

It is of interest that, with each new wave of concern, the issues that dominated the earlier wave were recycled. The result is that while the intensity of earlier concerns has receded, in part due to the induced technical and institutional changes, the concerns with the relations between resource and environmental changes and sustainable growth in agricultural production have broadened. During the 1980s, for example, concerns with the effects of more intensive agricultural production (a) on resource degradation through erosion, salinization and depletion of groundwater; and (b) on the quality of surface and groundwater through runoff and leaching of plant nutrients and pesticides, intensified. Terms that initially had been introduced by the populist critics of agricultural research, such as alternative, low input, regenerative, and sustainable agriculture, began to enter the vocabulary of the people responsible for agricultural research resource allocation.

The Agricultural Transformation

Contemporary concerns about the capacity to sustain the growth in the demands that societies are placing on their agricultural systems have emerged during the completion of one of the most remarkable transitions in the history of agriculture. Prior to this century almost all increases in food production were obtained by bringing new land into production. The few exceptions to this generalization were in limited areas of East Asia, the Middle East, and Western Europe (Hayami and Ruttan, 1985).

By the first decade of the twenty-first century, almost all increases in world food production will have to come from higher yields: increased output per hectare. In most of the world the transition from a resource-based to a science-based system of agriculture is occurring within a single century. In a few countries this transition began in the nineteenth century. Wheat prices, corrected for inflation, have declined since the middle of the nineteenth century. Rice prices have declined sine the middle of the twentieth century. These trends suggest that productivity growth has been able to more than compensate for the rapid growth in demand, particularly during the decades since World War II.

As we look toward the future, however, the sources of productivity growth are not as apparent as they were a quarter century ago. The demands that the developing economies will place on their agricultural producers owing to population growth and growth in per capita consumption arising out of higher income will be exceedingly high. Population growth rates are expected to decline substantially in most countries during the first quarter of the twenty-first century. But the absolute increases in population size will be large and increases in per capita income will add substantially to food demand. The effect of growth in per capita income will be much more rapid growth in demand for animal proteins as well as for maize and other feed crops. During the next several decades growth in food and feed demand arising from growth in population and income will run upwards of 4.0 percent per year in many countries. Many countries will experience more than a doubling of food demand before the end of the second decade of the twenty-first century.

It is apparent that the gains in agricultural production required over the next quarter century will be achieved with much greater difficulty than in the immediate past. Currently, difficulty is being experienced in raising yield ceilings for the cereal crops that had rapid yield gains in the recent past (Ruttan, 1989). The incremental response to increases in fertilizer has declined. Expansion of irrigated area has become more costly. Maintenance research, the research required to prevent yields from declining, is rising as a share of research efforts. The institutional capacity to respond to these concerns is limited, even in countries with the most effective national research and extension systems. Indeed, there has been considerable difficulty in many countries during the 1980s in maintaining the agricultural research capacity that was established during the 1960s and 1970s.

It is possible that within another decade advances in basic knowledge will create new opportunities for advancing agricultural technology to reverse the urgency of some of the preceding concerns. Institutionalization of private sector agricultural research capacity in some developing countries is beginning to complement public sector capacity. Advances in molecular biology and genetic engineering are occurring rapidly. But the date when these promising advances will be translated into productive technology seems to be receding. Thus it is particularly appropriate at this time to examine the implications for the international agricultural research agenda of the constraints which resources and the environment may impose on the sustainable growth of agricultural production into the twenty-first century.

The conversations reproduced in this book are organized around four general topics. The first focuses on what we really know about global climate change. What can we actually say we know compared to what we think or hope? In this group we have Dean Abrahamson, Norman Rosenberg, William Clark, and Steve Sonka. Abrahamson starts the discussion.

The second topic centers on the impact of global climate changes on agriculture and natural resources. Steve Rawlins provides the transition between the first and second groups, and then we have Paul Waggoner, Margaret Davis, Robert Chen, Zbigniew Bochniarz, and Pierre Crosson participating in the conversation. I visualize Crosson's presentation as the transition to the issues of micro-environmental change. Pedro Sanchez discusses some of the problems associated with tropical soils and tropical ecologies, and William Larson and H. H. Cheng discuss temperate region soil problems. Richard Jones discusses pests and pathogens that arise from both global climate change and some microenvironmental change, and Robert Munson reflects on some of his concerns with soil fertility.

Finally, we move to a discussion of the implications for agricultural research. Steve Rayner is concerned with decision making under the kinds of uncertainty that arise from the changes under discussion, and Steve Rawlins reflects on the research implications from a federal perspective. Eugene Allen discusses research implications from a state perspective.

It is from the open exchange of ideas from a variety of perspectives that important ideas arise and are defined. It is my hope that the readers of this book will continue the conversations and advance the programs needed to achieve sustained increases in agricultural production. They will be needed as we move into the first decades of the twenty-first century.

PART TWO
Global Climate Change

2
Greenhouse Gases and Climate Change

Dean E. Abrahamson

Abrahamson: At current growth rates in the emissions of greenhouse gases, we can expect increases in concentrations equivalent to a doubling of the pre-industrial concentration of CO₂ (carbon dioxide) by about 2030. Most of the general circulation models show an equilibrium heating - an increase of annual average global temperature - in the neighborhood of 3°-5° Celsius for a doubling of CO₂ concentration. Because of the large heat capacity of the oceans, and the time to transfer heat into the oceans, there is an ocean thermal delay generally represented as 20-40 years. That is the reason for the lag between the atmospheric concentration of greenhouse gases and the observed increase in atmospheric temperature.

A number of biogeochemical feedbacks are not incorporated into the general circulation models. They are not well understood. One estimate by Lashoff (1989) suggests that taking these feedbacks into account could lead to a global heating equivalent to that shown by the general circulation models. If that should be the case, and if we permit emission rates to continue at their present levels, we could be committed to a warming of 6-8° within the next three or four decades. Some of these feedbacks have a long-time constant. Some don't.

The global heating - the concentration of greenhouse gases and the resultant climate change - is irreversible: not, of course, in geologic time frames but in social or economic or political relevance time. The issue differs from most conventional environmental issues in that there are, for practical purposes, no scrubbers ~ there is no simple technical fix. There are some exceptions: chlorofluorocarbons and some of the other industrial chemicals. This means that in order to reduce emission rates the level of activities that produce these gases must be reduced.

Finally, I find it hard to convince myself that we aren't already committed to a warming of 3-5° Celsius as an equilibrium warming because of gases already in the atmosphere, plus those certain to be released while we debate policy response and implement it. What about uncertainty? The basic physics of the greenhouse effect is very well known. That there will be climatic change resulting from greenhouse gas emissions is a certainty. How much and when is not at all certain.

We started last spring to put together a faculty seminar at the University that will consider implications of climatic change for Minnesota. It is the first draft of a scenario for climatic change for Minnesota but has not yet been reviewed. It was done by my colleague, Peter Ciborowski.

We were deliberately conservative. We didn't take the high end of the scale for temperature or precipitation. The base case suggests an average temperature increase of one degree by the turn of the century and three degrees by 2030; additional frost-free days by 2030; a decline in degree heating days; an increase in degree cooling days; a 2 or 3 week earlier snow melt; 10 or 20 additional July days over 90°F; a reduction in summer soil moisture of 25 percent; and increased drought frequency and decreased runoff. In my view the changes are apt to be much more extreme, but I tend to be a little more pessimistic than some people.

In 1987 a conference sponsored by the World Meteorological Organization and UNEP and a couple of other organizations was held in Villach, Austria. Several of you were there. The group put together a scenario that projected larger temperature increases at high latitudes than at low, and more in winter than in summer.

The National Academy of Sciences, in a review published in 1987, addressed the question of likelihood. Large stratospheric cooling was regarded as virtually certain and global mean surface warming very probable. The suggested range for an equivalent doubling of CO₂ is 1-1/2° to 4-1/2° Celsius. Global mean precipitation increase is very probable as are the reduction of sea ice, polar winter surface warming, and rise in sea level. Summer continental dryness and warming are likely in the long term. The effects of climatic change are probably nonlinear. Some of the physical impact, sea level rise, for example, may be a linear function of average warming over some range, but the impact of the sea level rise will be highly nonlinear. I can't think of any impact that scales linearly with temperature.

The policy situation is evolving very rapidly. You don't hear talk anymore about winners and losers or that society's only response can be adapting to climatic change. You did a few years ago, but the talk pretty much disappeared as soon as the effects associated with rates of climatic change were understood.

Clearly, the emissions of greenhouse gases have to be reduced, and reduced substantially. Various estimates have been made of the necessary reductions in emissions of greenhouse gases to stabilize their atmospheric concentrations. For example, the EPA (Lashof & Tirpak, 1989) suggested a reduction in CO₂ emissions of between 50-80 percent; a 10-20 percent reduction in methane; elimination of the long life CFCs, and reduction of nitrous oxide of, as I recall, 85 percent. Thus, very, very substantial reductions in these gases are required to stabilize atmospheric greenhouse gas concentrations.

Bills pending before the Congress and other legislative bodies range all the way from stabilizing emissions to reductions of 20 percent or so by the end of the century. About 60 percent of the greenhouse gases appear to come from fossil fuels, the rest from a number of other sources. At the same time that we will be trying to restructure energy production and use to reduce emissions it will be necessary to try to cope with substantial unavoidable climatic change. ...

Table of contents

• Cover
• Half Title
• Title
• Copyright
• Contents
• Preface
• About the Contributors
• PART ONE INTRODUCTION
• PART TWO GLOBAL CLIMATE CHANGE
• PART THREE LOCAL AND REGIONAL RESOURCES AND ENVIRONMENTAL CHANGES
• PART FOUR RESPONSES TO CLIMATE CHANGE
• PART FIVE SUSTAINABLE AGRICULTURE AND THE FUTURE
• References