Bending the Curve:
Toward Global Sustainability
Paul Raskin, Gilberto Gallopin, Pablo Gutman, Al Hammond and Rob Swart
A report of the Global Scenario Group

PoleStar Series Report no. 8, 1998

GlobalScenario
Group

The

ë LESTAR
PO

Publication SeriesThis publication series is produced by the Stockholm Environment Institute’s PoleStar Project.
Named after the star that guided voyagers through uncharted waters, the multi-year PoleStar
Project addresses critical aspects of the transition to sustainability. Scenario analysis illuminates
long-range problems and possibilities at global, regional, national and local levels. Capacity
building strengthens professional capabilities for a new era of development. Policy studies fashion
strategies and actions. The PoleStar System© provides a user-friendly tool for organizing pertinent
data, formulating scenarios, and evaluating strategies for sustainable development. For more
information, visit http://www.seib.org/polestar.html on the Internet. The Global Scenario Groupwas established to carry forward the global aspects of this work.
The PoleStar publication series includes:
1. The Sustainability Transition: Beyond Conventional Development (Raskin, Chadwick, Jacksonand Leach)
2. PoleStar System Manual (Raskin, Heaps and Sieber)
3. Global Energy in the 21st Century: Patterns, Projections and Problems (Raskin and Margolis)
4. Water and Sustainability: A Global Outlook (Raskin, Hansen and Margolis)
5. Global Land and Food in the 21st Century: Trends and Issues for Sustainability (Leach)
6. Accounting for Toxic Emissions from the Global Economy: The Case of Cadmium (Jackson
and MacGillivray)
7. Branch Points: Global Scenarios and Human Choice (Gallopin, Hammond, Raskin and Swart)
8. Bending the Curve: Toward Global Sustainability (Raskin, Gallopin, Gutman, Hammond andSwart)
9. Conventional Worlds: Technical Description of "Bending the Curve" Scenarios (Heaps, KempBenedict and Raskin)

Global Scenario GroupThe Global Scenario Group engages a diverse group of development professionals in a long-term
commitment to examining the requirements for sustainability. The GSG is an independent,
international and inter-disciplinary body, representing a variety of geographic and professional
experiences. Its work program includes global and regional scenario development, policy analysis
and public education. The diversity and continuity of the GSG offer a unique resource for the
research and policy communities. The GSG pursues its objectives through research, publicationand collaboration with regional sustainable development projects. This report relies on the scenario
framework developed in Branch Points: Global Scenarios and Human Choice (PoleStar #7) toexamine alternative global futures. A companion document (PoleStar #9) provides technicaldetails. For reports and more information, visit http://www.gsg.org on the Internet.

Bending the Curve:
Toward Global Sustainability
Paul Raskin, Gilberto Gallopin, Pablo Gutman, Al Hammond and Rob Swart

Stockholm Environment Institute
Lilla Nygatan 1, Box 2142
S-103 14 Stockholm
SwedenPhone: +46 8 412 14 00
Fax: +46 8 723 0348
Email: postmaster@sei.se
Web: http://www.sei.se© Copyright 1998 by the Stockholm Environment Institute.
No part of this report may be reproduced in any form by photostat, microfilm, or any other means,
without the written permission of the publisher.
Front cover photo: View of Africa and Saudi Arabia from Apollo 17. NASA/NSSDC.

ISSN:
ISBN:

1400-7185
91-88714-57-8

Bending the Curve: Toward Global Sustainability

iii

TABLE OF CONTENTSACKNOWLEDGMENTS..................................................................................................... VII
SUMMARY ............................................................................................................................ IX
1. ISSUES AND CONCEPTS ...................................................................................................1
1.1
1.2
1.3
1.4

Triumphalism and Counterpoint ................................................................................................. 1
Dimensions of Sustainable Development ..................................................................................... 1
Scenarios of the Future................................................................................................................ 3
Aim and Structure of the Report.................................................................................................. 6

2. GOALS..................................................................................................................................7
2.1 Social Objectives......................................................................................................................... 7
2.2 Environmental Objectives ......................................................................................................... 14

3. THE PROBLEM OF UNSUSTAINABILITY ................................................................... 23
3.1
3.2
3.3
3.4
3.5

Reference Scenarios .................................................................................................................. 23
An Illustration........................................................................................................................... 24
Environmental Risk .................................................................................................................. 28
Persistent Poverty...................................................................................................................... 37
Conclusions .............................................................................................................................. 43

4. STRATEGIES FOR A TRANSITION............................................................................... 45
4.1
4.2
4.3
4.4
4.5
4.6
4.7

Policy Reform Scenarios............................................................................................................ 45
Meeting the Social Goals........................................................................................................... 46
Climate ..................................................................................................................................... 49
Energy ...................................................................................................................................... 52
Food and Land .......................................................................................................................... 56
Freshwater ................................................................................................................................ 61
Materials and Waste.................................................................................................................. 66

5. IMPLICATIONS FOR ACTION ....................................................................................... 69
5.1
5.2
5.3
5.4
5.5
5.6

Challenges ................................................................................................................................ 69
Agents of Change...................................................................................................................... 70
Science for Sustainability .......................................................................................................... 72
Symptoms and Causes: A Framework for Guiding Policy .......................................................... 73
Policy Directions....................................................................................................................... 76
Conventional Worlds and Beyond ............................................................................................. 80

REFERENCES........................................................................................................................ 83
ANNEX - SCENARIO HIGHLIGHTS................................................................................A-1

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Raskin, Gallopin, Gutman, Hammond and Swart

TABLE OF FIGURESFIGURE 1. SCENARIOS STRUCTURE WITH ILLUSTRATIVE PATTERNS OF CHANGE ............................................ 5
FIGURE 2. THE TEN REGIONS ................................................................................................................... 11
FIGURE 3. POPULATION SUFFERING FROM HUNGER AND A LACK OF SAFE DRINKING WATER IN 1995........... 11
FIGURE 4. GLOBAL OVERVIEW OF THE REFERENCE SCENARIO .................................................................... 25
FIGURE 5. CO2 EMISSIONS TO 2100 CORRESPONDING TO DIFFERENT STABILIZATION CONCENTRATIONS ..... 30
FIGURE 6. INDUSTRIAL CO2 EMISSIONS IN REFERENCE AND IPCC SCENARIOS ............................................ 31
FIGURE 7. POPULATION IN WATER STRESS ................................................................................................ 35
FIGURE 8. FOREST AREAS IN DEVELOPING REGIONS IN THE REFERENCE SCENARIO ..................................... 37
FIGURE 9. THE LORENZ CURVE AND GINI COEFFICIENT ............................................................................. 38
FIGURE 10. HISTORICAL U.S. GINI COEFFICIENTS ..................................................................................... 39
FIGURE 11. CHANGING INCOME DISTRIBUTIONS........................................................................................ 40
FIGURE 12. RELATIONSHIP BETWEEN NUMBER OF HUNGRY AND THE HUNGER LINE .................................... 41
FIGURE 13. HUNGER LINES VS. MEAN INCOME.......................................................................................... 42
FIGURE 14. SCENARIO TRAJECTORIES ....................................................................................................... 48
FIGURE 15. ENERGY-RELATED CO2 EMISSIONS PER CAPITA ...................................................................... 51
FIGURE 16. ANNUAL CO2 EMISSIONS........................................................................................................ 52
FIGURE 17. PRIMARY ENERGY REQUIREMENTS ......................................................................................... 53
FIGURE 18. ENERGY INTENSITIES IN THE SCENARIOS ................................................................................. 54
FIGURE 19. OECD ENERGY INTENSITY IMPROVEMENTS BY SECTOR IN THE SCENARIOS.............................. 55
FIGURE 20. LAND-USE IN THE SCENARIOS ................................................................................................ 61
FIGURE 21. WATER INTENSITIES IN THE SCENARIOS .................................................................................. 64
FIGURE 22. OECD WATER INTENSITY IMPROVEMENTS BY SECTOR IN THE SCENARIOS ............................... 65
FIGURE 23. POPULATION IN WATER STRESS IN THE SCENARIOS.................................................................. 66
FIGURE 24. UNSUSTAINABILITY TRENDS AND DRIVERS ............................................................................. 74

TABLE OF TABLESTABLE 1. INCOME, POPULATION, AND POVERTY IN 1995............................................................................. 8
TABLE 2. SELECTED SOCIAL INDICATORS IN 1995 ....................................................................................... 9
TABLE 3. SELECTED INDICATORS BY REGION IN 1995................................................................................ 10
TABLE 4. GLOBAL INDICATORS AND TARGETS .......................................................................................... 12
TABLE 5. ENVIRONMENTAL INDICATORS AND TARGETS ............................................................................ 16
TABLE 6. POLICY INSTRUMENTS TO ATTAIN THE PROPOSED SOCIAL OBJECTIVES ....................................... 77
TABLE 7. POLICY INSTRUMENTS TO ATTAIN THE PROPOSED ENVIRONMENTAL OBJECTIVES ........................ 78

Bending the Curve: Toward Global Sustainabilityv

DEDICATIONAs this document was going to print, we learned of the untimely passing of Katsuo Seiki.
The world has lost a great champion for a just and liveable future, and we have lost a close
colleague and friend. He will live on in the work of those he inspired.

vi

Raskin, Gallopin, Gutman, Hammond and SwartBending the Curve: Toward Global Sustainability

vii

ACKNOWLEDGMENTS
The authors are deeply indebted for the substantive input and critical feedback on earlier
drafts of this manuscript. Our topic — the requirements for a global sustainability
transition — is complex, cross-disciplinary and inherently normative. The comments ofnumerous individuals from diverse perspectives and backgrounds were invaluable inshaping our approach and formulations. These include our Global Scenario Group
colleagues (Khaled Fahmy, Tibor Farago, H.W.O. Okoth-Ogendo, Atiq Rahman, Setijati
Sastrapradja, Katsuo Seiki, Nicholas Sonntag, and Veerle Vandeweerd), Mike Chadwick,Gordon Goodman, Dan Kammen, Meir Carasso, Dale Rothman and many more. One ofus (Raskin) wishes to acknowledge the many insights gleaned from discussions with Bob
Kates, Bill Clark, and other colleagues on the Board on Sustainable Development, U.S.
National Research Council. Drs. Charles Heaps, Eric Kemp-Benedict and Gil Pontius of
the GSG Secretariat provided excellent scientific support and assistance throughout a longprocess of analysis, consultation, and documentation. We are grateful to Michael Keating
for editorial assistance. That said, any oversights or deficiencies in the manuscript are thesole responsibility of the authors.
We thank the United Nations Environment Programme for supporting a review meeting inTokyo. Finally, we are grateful to the Nippon Foundation for its generous assistance tothe work of the Global Scenario Group. The support of the Foundation and its staff madethis study possible.

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Raskin, Gallopin, Gutman, Hammond and SwartBending the Curve: Toward Global Sustainability

ix

SUMMARY
Introduction
Over the last few centuries, a mere heartbeat of historic time, humanity has moved to thebrink of a new evolutionary milestone — the planetary phase of civilization. The world
economy is expanding and becoming more integrated, profoundly reshaping the culturaland political landscape everywhere. This expansion is taking its toll on the natural
resources that support development. The human impact on the global environment has
grown from diminutive to elephantine. And, despite great wealth in the world, there is still
great poverty and suffering. As we drift along the arc of history, we see ahead of us therisk of both greater environmental peril and social friction. We also see the opportunity ofa safer passage to a more just and sustainable global society.
Bending the Curve looks at what it would take to steer human development onto a
more sustainable pathway during the 21st century. In its previous publication, Branch
Points: Global Scenarios and Human Choice, the Global Scenario Group developed threeclasses of scenarios to show possible pathways for the future. Conventional Worlds
scenarios assume we will continue on the current pathway of economic globalization, withevolutionary changes in institutions, and that developing regions of the world will movetoward industrial country patterns and values. Another set of scenarios, called
Barbarization, depict a world in which deepening social and environmental tensions are
not resolved, civilized norms erode, and great human misery ensues. The third type of
scenario, Great Transitions, envision fundamental social and institutional transformation
toward more sustainable forms of economic and social development, bringing a new andarguably higher stage of human civilization.
Bending the Curve examines the possibilities for sustainable development bypushing for important changes within an evolutionary Conventional Worlds context. The
shift to more sustainable forms of development must at least begin at this level, although
we will likely need more fundamental social changes to complete the transition to asustainable global society. This study shows how a comprehensive set of policy reforms
could bend the curve of development toward sustainability.

The Challenge of Sustainable Development
To assess the implications of current trends, and to guide policies to change those trends,
we introduce a set of explicit goals for long range sustainability. In developing
sustainability goals, we include both the environmental and social dimensions of thesustainable development concept. Environmental sustainability means changing humanactivities so they no longer threaten the natural resource base and ecological systems uponwhich economic development, human health and social well-being depend. Social
sustainability highlights the need to reduce absolute poverty and extreme inequality on
both moral and practical grounds. Social sustainability is essential because poverty is botha cause and an effect of environmental degradation. Moreover, a society festering withsocial tension will not have the means or inclination to make the environment a priority.

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Raskin, Gallopin, Gutman, Hammond and Swart

There are no blueprints for a transition to sustainability, but there are policy
reforms that could reduce environmental degradation, income disparity, and persistentpoverty. Humanity’s sustainability goals of today will need to be refined over time in lightof new information and events in the spirit of “adaptive management.” However, setting
provisional targets for sustainability will allow us to start developing strategies to avoid
critical risks, and will keep options open for the future.
We suggest sustainability indicators and targets for five broad environmental
challenges: stabilizing the climate within safe ecological limits, reducing the flow ofmaterials through economies, decreasing toxic waste loads on the environment, easing thepressure on freshwater resources and maintaining the integrity of ecosystems. The targets
call for substantial decreases in environmental pressures from OECD economies.
Developing and transitional regions of the world would increase some impacts, thengradually move toward OECD standards. The targets for carbon dioxide emissions,shown below, illustrate the pattern.

86Developing
4

2

Emissions(GtC/year)

10

OECD

2

Transitional
0
1990

2010

2030

2050

2070

2090

CO2 Emissions Targets

There can be no easy consensus on broad social goals, which will vary acrossworldviews and societies. We consider only a minimal set of objectives that have wide
international consensus: the provision of basic human needs such as adequate food, clean
drinking water, and access to health care and education. It is a sad legacy of our time thatthe extraordinary expansion of the aggregate global economy, which grew by a factor offive since 1950 alone, has not diminished the sum total of human misery. Some 1.3 billion
people live in absolute poverty, with nearly 900 million undernourished. The following
table underscores both the scale of destitution and the contrast between industrialized
OECD countries and other regions.

Bending the Curve: Toward Global Sustainability

xiSocial Indicators in 1995
Macro-Region

Income($/capita)

Population(millions)

Hunger(%)

Unsafe Water(%)

Illiteracy
(%)

OECD

20,250

910

1

1

2

Non-OECD

3,130

4,770

19

28

29

World

5,880

5,690

16

24

24

Guided by the declarations of recent international conferences, we propose a set ofchallenging though attainable social goals. They are reducing the incidence of hunger,
unsafe water and illiteracy in half by 2025 and in half again by 2050, based on 1995
figures. The number of hungry, for example, would fall from 900 billion in 1995 to 445
billion by 2025, and 220 billion by 2050. As a fraction of projected world population,
hunger would fall even faster, from 16% in 1995 to about 2% in 2050.

The Problem of Unsustainability
Are the sustainability goals compatible with conventional development premises?
Drawing on the analyses and assumptions of many international organizations, we havepainted a picture of global development under a business-as-usual approach. We call thisthe Reference scenario and use it to examine emerging problems. We use this baseline toassess the types of policy changes needed.
The conventional wisdom is that we will have larger, older and more urban
populations. Economies will continue to grow rapidly everywhere, driven by expanding
global trade, financial transactions and capital flows. Advances in information technology,
biotechnology and other innovations will gradually change production and consumption
patterns. Developing countries will emulate the industrial country development model,
and there will be progressive homogenization of global culture around the values ofmaterialism and individualism. Significant income disparity between rich and poor
countries, and between the rich and poor within countries, will remain a tenacious anddebilitating social trend. Development will continue to run down the environmental baseupon which it depends by using resources faster than nature can produce them, and by
releasing pollution faster than it can be safely assimilated.
Among the implications of the Reference scenario:• Between 1995 and 2050, world population increases by more than 50 per cent, average
income grows over 2.5 times and economic output more than quadruples.
• Food requirements almost double, driven by growth in population and income.
• One billion remain hungry as growing populations and continuing inequity in the
sharing of wealth counterbalance the poverty-reducing effects of general economic
growth.
• Requirements for energy and water increase substantially.

xii

Raskin, Gallopin, Gutman, Hammond and Swart• Carbon dioxide emissions soar, threatening the global climate, and risking serious
ecological, economic and human health impacts.
• Forests are lost to the expansion of agriculture and human settlement areas, and otherland-use changes.
5

1995
2025
2050

Relative to 1995

4
3
2
1
0
Population GDP per
Capita

World
GDP

Food
DemandHungerPrimary
EnergyWater

CO2Emissions

ForestArea

Overview of Reference Scenario

Measured against our sustainability criteria, the Reference scenario would be arisky bequest to our 21st century descendants. The increasing pressure on environmental
systems — the combined effects of growth in the number of people, the scale of theeconomy and the throughput of natural resources — is environmentally unsustainable.
Environmental degradation could undermine a fundamental premise of the scenario:
perpetual economic growth on a global scale. Conventional development patterns also failto address the social goals for sustainability, because the level of absolute poverty andhunger persists into the middle of the next century.

Strategies for a Transition
What strategies could bend the curve of development toward the sustainability goals?
Policy Reform scenarios begin with visions of the future that satisfy the sustainability
goals. Rather than a forecast, the scenario is constructed as a backcast from a desired
future in 2050 and beyond. The aim is to identify plausible development pathways forgetting there, including the choices and actions for shaping a sustainable future.
In the Policy Reform scenario, poverty reduction goals are realized throughinitiatives to increase the incomes of the poor. Two types of equity increases relative tocurrent trends are critical to meeting these goals: greater international equity between richand poor countries and greater national equity within countries. International equity is
aided by strategies that accelerate the convergence of developing and transitional regions
toward OECD levels of development. National equity is improved through income
distribution policies. Under the scenario, “growth with equity” becomes the prevailing
philosophy in development strategies.

Bending the Curve: Toward Global Sustainability

xiii

Meeting the environmental goals in the Policy Reform scenario requires dramatic
adjustments in the use of resources, abatement of pollution, and protection of ecosystems.
In the face of increasing populations and rapid economic growth, the simultaneous
satisfaction of environmental and social targets presents an exceedingly daunting
challenge. Energy, water and resource use efficiency must increase substantially.
Renewable energy, ecologically based agricultural practices, and integrated eco-efficientindustrial systems must become the norm. To live within water and land constraints, anumber of developing countries must rely more heavily on food imports, countering recent
trends in industrialized regions of withdrawing lands from agricultural production. The
scale of the required transition is illustrated by comparing Reference and Policy Reform
scenarios across selected social and environmental dimensions, as shown in the figure
below.

1995

2050

1995

2050

1995

Forest Loss

Sulfur Emissions

2050 1995

2050

Toxic Waste

2050

Reference

Global Patterns Compared

2050

2050 1995

1995

Carbon Emissions

1995

2050

Water Use

Energy Requirements

1995

HungerNational Equity

International Equity

1995

Policy Reforrm

2050

xiv

Raskin, Gallopin, Gutman, Hammond and Swart

Conclusion
Environmental degradation is not a necessary outcome of development. It results from a
set of historically contingent choices for technology, production processes andconsumption patterns. Similarly, poverty and extreme inequity are not inevitable, but are
the outcome of a specific set of social policy choices. Reversing the negative trends, andcreating a transition to global sustainability will not be easy. It will require a widespreadconviction that action is necessary and will depend on finding sufficient political will for
action. Then, the institutions, policies, and technologies for translating intentions into
real-world solutions must be harnessed or forged. The primary agents for change aregovernments, businesses, and the new institutions of civil society, the proliferatingcollection of non-governmental organizations engaged in addressing the full range ofenvironmental and social issues.
Science has a critical role in the sustainability transition. It must broaden its focus
and develop a systems approach to understanding complex social and ecological processes
and their interactions.
The challenge is to develop a science of sustainability thatmaintains a commitment to rigor, while recognizing the inherent uncertainty in complex
systems and the need for advice on how to make sustainable choices. Scenario analysis
can play a linchpin role by synthesizing diverse findings from natural and social sciences,and linking science to the public and policy dialogues on the future.
The message of the Reference scenario is that emerging environmental and social
stresses pose grave risks. Complacency is not a valid option for those who take theresponsibility of passing on a secure future to our descendants as a moral imperative. The
Policy Reform scenario shows that the cumulative effects of a comprehensive family offeasible incremental technological and policy adjustments can take us a long way down thesustainability path. Numerous policy levers could be used to induce environmentally
sustainable practices and promote poverty alleviation. The appropriate package of
instruments, including eco-taxes, market mechanisms, regulation, income transfers, humancapital investment, technology transfer, economic stimulation, information campaigns, willvary with the issue, level of governance, and local concerns.
The challenge ahead is to mobilize the political will needed to pick up the policy
tools. Can the global movement for sustainability overcome the resistance of special
interests, the myopia of narrow outlooks, and the inertia of complacency? Are
fundamental changes required in values and lifestyles that transcend Conventional Worlds
assumptions — a Great Transition? If this generation can begin to bend the curve ofdevelopment toward sustainability, it will keep future options open, bestowing the gift ofchoice to posterity.

1. ISSUES AND CONCEPTS
Ours is an age of profound transformation and great uncertainty about the future. Overthe last few centuries — a mere heartbeat of historic time — the human impact on the
global environment has grown from diminutive to elephantine. Now the human enterpriseis on the brink of a new evolutionary milestone — the planetary phase of civilization. Thisepochal transition poses weighty challenges for thought, policy, and action. To reflect on
the human condition and destiny at the end of the 20th century is to enquire about thetroubling perils ahead as we drift along the arc of history. But it is also to examine thepossibility of a salutary passage to a more just and sustainable global society.

1.1 Triumphalism and Counterpoint
A striking feature of the current era is the astounding expansion of the world economic
system, the culmination of forces launched several centuries ago with the emergence ofEuropean capitalism. By liberating nascent human potential for innovation and ingenuity,
capacity for greed and acquisitiveness, and hunger for liberty and modernism, the new
system set in motion a perpetual revolution in values, institutions, technology andknowledge. This process was further accelerated by the industrial explosion, which
continues in the form of the tumultuous technological changes of our time.
Looking ahead to the new century, conventional wisdom sees further massivechange as these historic forces play out on a global field — populations may double, theworld economy quadruple, and environmental pressures surge (IPCC, 1992b; Raskin etal., 1996). A common theme is that societies everywhere will gradually converge toward
common institutional and cultural assumptions in the context of globalizing economies(OECD, 1997). War, social opposition, and stubborn traditionalism impeded the forwardmarch of the ascendant market system in the past. But with the collapse of the socialist
experiments in Russia and elsewhere, the expansion of global markets, and the headyadvance of new technology, the millennial glee of cheerleaders for global capitalism,
anticipating a cornucopia for all in the new century is, perhaps, understandable (Schwartz
and Leyden, 1997).
But there are substantial challenges that must be overcome and fundamental
questions addressed. How will a growing human enterprise, one that already issignificantly perturbing natural planetary processes, be reconciled with environmental
limits? How will the deep social fissures between the north and the south, the rich and thepoor, parochialism and globalism, be ameliorated? And the question posed by Socrates
long ago remains: how shall we live?

1.2 Dimensions of Sustainable Development
In rhetoric, if not yet in agenda and action, the nations of the world pronounced theircommitment to sustainable development at the 1992 Earth Summit. In its classic
formulation, sustainable development “meets the needs of the present withoutcompromising the ability of future generations to meet their own needs” (WCED, 1987).
At the heart of the concept is the powerful ethical imperative that we strive to consume

2

Raskin, Gallopin, Gutman, Hammond and Swartand produce in a manner that is tempered by concern for the well-being of ourdescendants. The new paradigm for development demands that we take a multigenerational view in seeking to harmonize socio-economic and environmental goals.
Broadly, what sustainable development seeks to sustain is the integrity of
combined human and natural systems as they interact and condition one another over time.
The sustainability of such socio-ecological systems is a dynamic process of development,
not a static condition. A sustainable system is resilient to disturbance and flexible inadapting to changing circumstances (Raskin et al., 1996).
Not surprisingly, in the translation of the principle of sustainable development into
specific targets and action, the philosophical consensus shatters into a cacophony ofdefinitional debates, interpretations and slogans. The concept is sufficiently rich andprotean to refract the full diversity of human interests, values and aspirations. Bankers,social critics and environmentalists have all decanted old wine into this new bottle.
Nevertheless, sustainability remains an irreducibly holistic concept that compels
integration over perspectives, spatial scales, and time.
Sustainable development as a quality of coupled environmental and human systems
has both biophysical and socio-economic dimensions. Biophysical sustainability seeks tomaintain ecosystems, bio-geochemical cycles, and natural resources for perpetual humandevelopment. Beyond such anthropocentric requirements, for many, the preservation of
the natural heritage and the survival of species are intrinsic values not requiring utilitarianjustification. In any case, endless quantitative growth is an impossibility on a finite planet,though qualitative improvement in products, skills and culture need never cease in anenvironmentally sustainable world (Daly, 1996). Biophysical sustainability draws attention
to the scale of the economic system and the degree to which human activity transforms
nature and threatens environmental systems. Biophysical goals can be made operationalby setting criteria in terms of key environmental and resource indicators.
The second face of sustainability is socio-economic. For many who have joined
the sustainability discussion, though certainly not all, achieving basic social goals — the“needs” of today and of future generations in the Brundtland formulation — is taken as a
pre-analytic moral imperative. Eliminating hunger, providing access to education andhealth services, and diminishing inequality between and within regions are sufficient on
ethical grounds alone, whether or not they are necessary antecedents to environmental
sustainability. Indeed, there are plausible “solutions” to the problem of environmental
sustainability that are politically and socially repressive (Gallopin et al., 1997).
However, beyond the moral imperative for reducing human deprivation, there areimportant objective links that couple social goals to environmental conditions. For
example, poverty is both a cause and an effect of environmental degradation (World Bank,
1996). The desperately poor are likely to mine nature for immediate survival, not preserve
it for a dubious future. Moreover, the social cohesion required for a comprehensive
sustainability transition is undermined in a society where the needs of its citizens formaterial well-being and just treatment are not met. At the global level, regional disparities
foster migration pressure, environmentally unfriendly trade and development patterns, anddifficulty negotiating international environmental agreements.

Bending the Curve: Toward Global Sustainability

3

Thus, the socio-economic and environmental aspects of sustainability are highlyinterdependent. If a society permits excessive environmental deterioration, it risks
undermining the economic welfare of its citizens, the legitimacy of its political systems,
and the endurance of its institutions. If a society festers with social tension and instability,
it is not likely to make the environment a priority, or enjoy the institutional capacity for
implementing a sustainable form of development. We take as a fundamental principle,
therefore, that the socio-economic and biophysical dimensions of the sustainability
transition must be treated in a unified framework.

1.3 Scenarios of the Future
Scenario analysis offers structured accounts of possible long-range futures. The value of
scenarios lies not in their capacity to predict the future, but in their ability to provide
insight into the present. By helping to identify drivers of change, the implications ofcurrent trajectories and options for action, scenarios bring the future to bear in today’s
decisions. This is a critical contribution since the world is dominated by fragmented
rationality — firms concerned with profit, decision-makers with short-term agendas,
scientists with subspecialties, and households with material accumulation. The danger isthat such local rationality taken in aggregate leads to global irrationality, to a pattern for
the whole system that would have been chosen by no one.
Scenarios enlarge the canvass for reflection to include a holistic perspective overspace, issues and time. They illuminate the ways in which the contradiction of unabatedgrowth of human activity on a finite planet might be resolved. In conventional
development paradigms, long-range global affluence and environmental preservation are
assured, it is hoped, through market adaptations, perhaps with the prod of well-designed
policies. But there are other ways in which the tension between economic growth andenvironmental limits might be reconciled. Some visions are bleak, including the possibilityof catastrophic environmental and social collapse — or, perhaps to prevent suchbreakdown, the emergence of authoritarianism. Some are idealistic, picturing a root andbranch transition where post-consumerist values and lifestyles form the basis for a morejust, humane and ecological stage of civilization.
These three archetypal scenarios of the future — Conventional Worlds,
Barbarization, and Great Transitions are described in a previous publication (Gallopin etal., 1997). The Conventional Worlds class of scenarios assumes that current trends playout without major discontinuity and surprise in the evolution of institutions, environmental
systems and human values. In Barbarization scenarios, fundamental social change occurs,
but is unwelcome, bringing great human misery and collapse of civilized norms. Finally,
Great Transitions also represent fundamental social transformation but a new andarguably higher stage of human civilization is posited.
This wide and contrasting scan of possible futures, all consistent with current
conditions and trends, is necessary because the long-range future is not predictable. The
global socio-ecological system is far too complex for that. Scientific understanding ofcurrent conditions, forces of change, and systems dynamics is limited. But even with
precise knowledge, uncertainty and surprise are inherent in complex systems.

4Raskin, Gallopin, Gutman, Hammond and Swart

Moreover, the future is subject to human choices that have not yet been made andactions that have not yet been taken. Indeed, the entire discussion of a transition tosustainable development is premised on the notion that humankind can, to a degree,
influence its destiny. In this sense, scenarios can serve as self-fulfilling attractors,
desirable visions of the future that help galvanize effective actions for their realization.
The future beckons to the present through our capacity to envision goals and act toachieve them.
Scenarios can be elaborated in great narrative and quantitative detail with many
variations possible within each of our major classes. Figure 1 shows two such variants foreach of our three classes along with illustrative sketches of how key variables —population growth, economic scale, environmental quality, distributional equity,
technological change and social conflict — might change over time. In fact, the curves ofchange will vary depending on the worldview of the observer. For example, the curve
suggesting increasing environmental deterioration under the market-driven Conventional
Worlds-Reference scenario would be unacceptable if one believed that market responses(e.g., through changing prices) would induce the required behavioral changes andinnovations for environmental protection.
The focus of this study is the Conventional Worlds-Policy Reform scenario. The
Policy Reform scenario is distinguished from the business-as-usual Reference scenario by
the assumption that comprehensive and coordinated government action is taken forsustainability. The scenario is used to explore the requirements for achieving sustainability
and the challenges for policy within a Conventional Worlds framework. Of course, theemergence of the necessary political will for imposing sustainability constraints on a
growth-driven global economy and consumerist culture — the essence of the Policy
Reform scenario — is by no means assured. Nevertheless, policy reforms are the point of
departure for a sustainability transition, even if, ultimately, one must imagine more basic
changes in human institutions and values.

Bending the Curve: Toward Global Sustainability

5

Figure 1. Scenarios Structure with Illustrative Patterns of Change
Source: Gallopin, et al. (1997)

Such changes might draw on elements of Great Transitions scenarios, which intheir pure forms are visionary responses to the sustainability challenge that include a
resurgence of quality values as a component of human welfare, high valorization ofnature, equitable wealth distribution, and strong social solidarity. The Eco-communalism
variant embraces the principles of strong decentralization, small-scale technology, andeconomic autarky. The New Sustainability Paradigm variant is a more cosmopolitan
vision that would transcend and transform urban and industrial civilization, and maintainglobal linkages and solidarity, rather than retreat into localism.
But what if increasing environmental and social crises overwhelm market
adaptations, and policy intervention and value change are insufficient? Then, the threatof a descent into Barbarization would loom. In an extreme variant, Breakdown scenarios
envision cultural disintegration and economic collapse, a degeneration of civilization intoa primitive world of all-against-all. The Fortress World variant features an authoritarian
response to the threat of breakdown. Ensconced in protected enclaves, an elite safeguards
its privilege by controlling an impoverished majority and managing critical natural
resources. Outside the fortress there is repression, environmental destruction, and misery.

6

Raskin, Gallopin, Gutman, Hammond and Swart

1.4 Aim and Structure of the Report
The taxonomy of scenarios offers a useful point of departure for understanding where theworld system might be going — and where it would need to go to meet social andenvironmental goals. Though the framework is highly idealized, greater texture andrichness can be introduced by allowing for variation across regions and providing concrete
stories of how the scenario themes might play out. Also, a scenario may jump to aqualitatively different one at critical moments when unresolved socio-ecological tensions
and contradictions lead to a branching of possibilities.
In this report, we reduce this complexity by narrowing our focus to theConventional Worlds class of scenarios. It is true that the fundamental premises of thesescenarios — evolutionary change in institutions, global convergence of economies andcontinuity in values — are not inevitable. As we have argued, discontinuities lurk in theform of Barbarization nightmares and Great Transitions visions — or as surprises that wecannot anticipate. Complacency about deep threats to civilization would certainly be both
imprudent and unethical. Moreover, the emergence of life-styles and values that transcend
the conventional paradigm must be part of a sustainability transition.
Nevertheless, the center of the policy discussion today lives in the Conventional
Worlds niche of the landscape of future visions. Political processes inherently tend to seek
to resolve conflicting interests gradually. When it comes to sustainable development, theperception of conflict — between the environment and economic growth, between richand poor, between the present and the future — is on a colossal scale. Despite somepositive trends, the 1997 United Nations General Assembly review of progress in the five
years since Rio found that critical problems were deepening (UNDPCSD, 1997). In thenear term, a gradual tilt toward effective policies for sustainable development is the mostthat can be expected. Even this would constitute a critical historical shift towardsustainability.
In this spirit, we introduce a broad set of environmental and social criteria to serve
as goals for long-term sustainability (Section 2). Then, to clarify the character and scaleof the policy challenge, we examine how an illustrative business-as-usual Conventional
Development-Reference scenario fares against these criteria (Section 3). Next, wedevelop a Conventional Development-Policy Reform scenario that includes an alternative
set of socio-economic, environmental and resource patterns, which seeks to meet thesustainability criteria (Section 4). Finally, we discuss the strategic implications — thekinds of policy steps needed to begin bending the curve of history toward a sustainable
development path (Section 5).

Bending the Curve: Toward Global Sustainability

7

2. GOALS
Sustainable development is about harmonizing human development with the environmental
constraints of the planet. It is also about reconciling the needs of present generations with
the needs of the future. In broad brush, a vision of sustainability for the next century
might include (Gallopin et al., 1997):• eradication of absolute poverty, malnutrition and famine, and universal entitlement tobasic social services such as health care and education;• improving quality of life everywhere and expanding possibilities for fulfillment;• declining economic and social disparities;• increasing environmental quality, with critical biological resources recovering, pollution
under control, and climate stability in sight;• infrequent violence and armed conflict; and• stable global population.
The challenge is to move the international commitment to sustainability from vision
to action. To design and test appropriate policies, the broad goals must be expressed interms of specific quantitative objectives. Recognizing that any set of criteria for asustainable world must necessarily be tentative and partial, it is nonetheless useful todescribe a preliminary set of minimum objectives — both social and environmental — andthe indicators that might gauge progress toward them.
To establish quantitative objectives, three sets of choices must be made: first,
which indicators are to be used to measure progress toward sustainability; second, which
values of these indicators represent sustainable conditions and hence provide targets
against which to measure progress; and third, how rapidly these targets are to be achieved.
These choices are to some degree subjective by nature, dependent not only on theinterpretation of uncertain scientific information, but also on the cultural preferences andinterests of an individual, a community, a country. This implies that different societies
might choose different sustainability criteria.
For reasons of simplicity and comparability, a common set of core global
indicators is used in this report. The indicators and targets set the constraints on Policy
Reform scenarios. They provide provisional guidelines for the scope, scale, and timing ofstrategic actions required for a transition to sustainability. However, there are no
blueprints — sustainability indicators and targets will need to be refined over time in lightof new information, events and perspectives. Sound sustainable development practices
will be an instance of “adaptive management.” Today we can only begin the long processof navigating a path across uncharted seas toward sustainability.

2.1 Social Objectives
Taken broadly, the notion of setting social goals could be construed to imply fundamental
normative questions, such as visions of the good society of the future. There can be noeasy consensus on these matters, since the range of perspectives will vary across the full8

Raskin, Gallopin, Gutman, Hammond and Swart

range of worldviews and political philosophies. The discussion here is more limited inscope, focusing on a narrower set of goals that have wide international consensus: theprovision of basic human needs, such as adequate food, clean drinking water, and accessto health care and education.1
At a minimum, this report argues, sustainability must mean achieving such social
goals. However measured, the human condition today falls far short of this standard. It isa sad legacy of our time that the extraordinary expansion of the aggregate global economy— by a factor of five since 1950 alone — has not diminished the sum total of humanmisery. The percentage of people destitute may have declined, but not the absolute
number. Not only has absolute poverty coexisted with rapid economic growth, to a large
degree it has been generated by the very systems that provide the engine of that growth(Gallopin, 1994).
The prevalence of poverty in the world today is an oft-told story that can only besummarized here (UNDP, 1997). We begin by considering the stunning contrast between
highly developed countries (OECD) and others (Table 1).2
Table 1. Income, Population, and Poverty in 1995
Macro-Region

Income($/capita)

Population(millions)Absolute Poverty(millions)OECD

20,250910

12Non-OECD

3,130

4,770

1,300

World

5,880

5,690

1,312

Sources: Income from CIA (1997); Population from UN (1997); Non-OECD poverty figures from UNDP
(1997); OECD poverty figures equated with hunger estimates

Nearly 85% of world population resides in non-OECD countries, where 27% live
in absolute poverty.3 The 1.3 billion living in such dire poverty exceeds the entire
population of the OECD countries. Using GDP per capita as a proxy for average income,we see from Table 1 that people in OECD countries are 6.5 times richer than in non-1

A broader perspective on alternative social visions will be the subject of a subsequent study of the Global Scenario
Group that will take up Great Transition scenarios, which were referred to in Section 1 and elaborated in Gallopin
et al. (1997).

2

Throughout the report we summarize results for two macro-regions, a more developed region as represented by themember countries of the Organization for Economic Cooperation and Development (OECD), and the rest of theworld (non-OECD). Mexico, the Czech Republic, Hungary, Poland and Korea are not included in the OECD,
although they are recent members.

3

The absolute poverty level is defined by the World Bank (1990) as individual consumption expenditures less than
$1/day or about $370/year in 1985 dollars, which is equivalent to about $525/year when inflated to 1995 dollars.

Bending the Curve: Toward Global Sustainability

9OECD countries.4 Note that the 15% of world population that resides in the wealthiercountries claims 55% of global income (the figure is 75% when GDP is expressed in MER
rather than PPP terms). Moreover, the disparity between the world’s rich and poor has
been increasing. According to one estimate, the richest 20% were 30 times better off thanthe poorest 20% thirty years ago, and are now 61 times better off (UNDP, 1996).
There are many possible measures of the status of human development. We focus
here on four indicators that serve to represent key categories of human well-being. These
are: chronic undernourishment (represented by hunger levels), availability of clean water(measured in terms of the population with unsafe drinking water), education (gauged by
the level of adult illiteracy), and human health (a proxy is life expectancy at birth). The
global situation for the four indicators is reported in Table 2. The indicators can be
expanded and combined, for example, the Human Development Index (UNDP, 1997)
combines average income per capita, literacy, and life span.
Table 2. Selected Social Indicators in 1995
Macro-Region

Hunger(%)

Unsafe Water(%)

Illiteracy(%)

Life Expectancy(years)

OECD

1

1

2

77

Non-OECD

19

28

29

64

World

16

24

24

66

Sources: See notes to Table 3

Not surprisingly, the disparities that were observed in the incidence of poverty
between OECD and non-OECD regions are also reflected in these more tangible
measures. In non-OECD regions, about 880 million people are undernourished today,
18% of the population in those regions. Moreover, 1.35 billion people, roughly 28% of
the population, do not enjoy reliable and sanitary sources of drinking water. The
cumulative effects of the lack of basic education are indicated by the 29% of the adult
population that is illiterate. Finally, life expectancy at birth in non-OECD regions remains
substantially below OECD averages, though there have been impressive increases in recent
decades. Life expectancy in developing countries rose from 46 to 62 years between 1960
and 1994, as infant mortality declined from 149 to 39 per 1000 live` births (UNDP, 1997),
and death from infectious diseases declined (WHO, 1997c).
Values for the social indicators by region are presented in Table 3. The ten global
4

Unless stated otherwise, national currencies in this report are expressed in common units adjusted for Purchasing
Power Parity (PPP). National PPP-adjusted GDP per capita are taken from CIA (1997). The PPP approach, inwhich prices of a common “basket of goods” are compared across countries, gives a more realistic picture of
relative incomes than the more commonly used Market Exchange Rates (MER) (WRI, 1996a). Use of PPP has theeffect generally of raising the estimated incomes in developing countries relative to rich countries. In MERconverted terms, the ratio between OECD and non-OECD GDP per capita is about 19, considerably higher than the
figure of 6.5 reported in the text.

10

Raskin, Gallopin, Gutman, Hammond and Swartregions used for the analysis throughout this report are shown in Figure 2. For context,
also shown on Table 3 are GDP per capita and a measure of income inequality (the ratioof the income of the poorest 20% to that of the richest 20%).5 Africa fares least wellacross all four indicators. More than one-third of the population is undernourished andnearly half are without safe drinking water. South and Southeast Asia and the Middle
East also register high levels of deprivation, with China and Latin America not muchbetter. The information on hunger and unsafe drinking water is presented graphically in
Figure 3.
Table 3. Selected Indicators by Region in 1995

RegionHunger(%)

UnsafeWater(%)

Illiteracy
(%)

Life
Expectancy(years)

GDP/Cap($)

Poorest 20%
divided byRichest 20%

Africa

34

49

45

55

1,620

0.13

China+

16

20

18

69

2,890

0.14

Latin America

14

17

14

69

6,000

0.07

Middle East

16

27

38

65

5,260

0.10

South & SE
Asia

19

35

40

63

2,580

0.18

Eastern Europe

1

7

0

71

5,950

0.23

FSU

4

8

0

67

4,110

0.22

North America

2

0

0

77

26,950

0.11

Pacific OECD

1

0

0

79

21,1000.16

Western Europe

1

1

4

76

15,7300.19

Sources: Hunger (see notes to Sheet S-2); unsafe water = 100% - access to safe drinking water; access tosafe drinking water for 1980-1995 (WHO, 1997b; World Bank, 1997), set to 100% for high-income OECD
countries, value for Ukraine used for missing values in FSU; illiteracy = 100% - adult literacy; adult literacy
for 1990-1995 (World Bank, 1997), set to 100% for countries in the OECD, Eastern Europe and FSU withno data; life expectancy at birth for 1990-1995 (World Bank, 1997); GDP per capita in PPP (CIA, 1997);
income ratios (see notes to Sheet S-1).

5

Regional income inequality is computed as the population-weighted average of country level data.

Bending the Curve: Toward Global Sustainability

11

Figure 2. The Ten Regions
1,500
Africamillions of people

1,250

C hina +Latin America

1,000
M iddle East

750

S+ SE Asia
Eastern E urope

500
FS U

250

O EC D0
HungerUnsafe W ater

Figure 3. Population Suffering from Hunger and a Lack of Safe Drinking Water in 1995
Source: See Table 3

Poverty levels in a given country depend on both average income and distributionof income. As a general principle, for a given average level of income, the more skewed
the distribution, the greater the fraction of the population in absolute poverty. This
relationship can be gleaned from the data in Table 3. Eastern Europe and Latin America
have similar average incomes, but income disparities are much greater in Latin America, as
are levels of hunger. Income distributions are similar in China+ and Africa, but average
incomes in Africa are much lower than in China+, with correspondingly higher levels of12Raskin, Gallopin, Gutman, Hammond and Swartabsolute poverty. The compact income distributions for the Former Soviet Union andEastern Europe — the ratios of the incomes of the poorest 20% to the richest 20% aregreater than 0.2 — are consistent with the historic emphasis on meeting the basic needs oftheir citizens.
Social goals for sustainability may be expressed in the language of reduction
targets for each measure of human deprivation. Here we rely on the work of a series ofinternational conferences that over the past few years have attempted to define goals forthe reduction of human deprivation and the provision of the opportunity for a dignified life
for all.6 Each of the indicators reflects a different dimension of poverty.
At the 1996 World Food Summit, it was resolved that undernutrition was to behalved by the year 2015 (FAO, 1996d). To achieve this goal, the number ofundernourished people must decline from 900 million today to roughly 445 million over
20 years. Based on the historical record, this is a quite ambitious goal, because thenumber undernourished fell only about 70 million between 1970 and 1990 (FAO, 1996d).
In the spirit of the World Food Summit goal, but allowing for some slippage, thisreport proposes a minimum target for hunger reduction in Policy Reform scenarios ofhalving undernourishment by 2025 and halving it again by 2050. The targets are definedin terms of the absolute number of undernourished: by 2050, the number ofundernourished people is targeted to fall to one-quarter of its 1995 value (Table 4). As afraction of world population, hunger falls faster, from about 16% in 1995 to just over 2%
in 2050, since population is assumed to grow from about 5.7 billion in 1995 to 9.4 billion
over this period, assuming mid-range population projection levels (UN, 1997).
Table 4. Global Indicators and Targets
Indicator
HungerUnsafe Water

Illiteracy

Life Expectancy

6

millions of people

1995
900

2025
445

2050
220

% of 1995 value

-

50%

25%

% of population

16%

6%

2%

millions of people

1,360

680

340

% of 1995 value

-

50%

25%

% of population

24%

9%

4%

millions of people

1,380

690

345

% of 1995 value

-

50%

25%

% of population

24%

9%

4%

Years

The approach follows BSD (1998).

66> 70 in all countries

Bending the Curve: Toward Global Sustainability

13

Strong commitments to universal provision of safe drinking water have been arecurrent theme in human development conferences and in the policy goals of multinational organizations (WHO, 1997a). Unfortunately, there is a history of boldpronouncements that go unmet, such as the Decade of Safe Drinking Water in the 1980s.
As with hunger, we assume that the population without safe water is cut in half by 2025.
This corresponds to a minimum level of safe water service of about 85% for rural and
95% for urban dwellers. The goal for 2025 may be compared to today figures of 50% and
75% safe water access in rural and urban areas, respectively, in many developing
countries. The 2050 target assumes another halving, corresponding to over 95% access tosafe water everywhere.
Similarly, the World Summit for Social Development (WSSD, 1995) and The Fifth
International Conference on Adult Education (UNESCO, 1997) articulated extremely
ambitious goals for the reduction of illiteracy, such as the elimination of female illiteracy
by the year 2000. While these are no doubt unrealistic, meeting the goals of halving by
2025 and again by 2050, as shown in Table 4, is certainly a plausible minimal target in aworld in which education for all is made a priority.
Finally, there is every reason to believe that aggressive policy actions in the healthsector can continue. The goals expressed at such meetings as the international World
Summit for Social Development (WSSD, 1995) have been quite optimistic, though
imprecise. A specific near term goal is for life expectancy at birth to be greater than 60
years for every country of the world (WHO, 1997a). Ultimately, life expectancy indeveloping regions can be expected to approach that of the OECD regions. A reasonableintermediate goal is that average life expectancy in all countries exceeds 70 years by 2025.
The social goals for the sustainability transition that we have introduced here set achallenging agenda for development. Even as general economic growth tends to drive
absolute poverty down, trends in population growth and increasing income disparity tend
to drive it higher. Indeed, as will be seen in Section 3, the Reference scenario analysis
shows that conventional development assumptions alone are not likely to lead to these
reductions. Rather, the number of people in hunger, to take one example, would notdiminish.
As expressions of different faces of poverty, the social needs represented by thevarious indicators have common roots. In assessing and constraining scenarios, we shallfind it convenient to focus attention on a single indicator to highlight results and to boundthe technical analysis. In particular, hunger-reduction targets will play a critical role inevaluating the sustainability of Reference scenarios and in defining targets for Policy
Reform scenarios. A reduction in hunger is correlated with the alleviation of the entire
nexus of unfulfilled basic needs associated with absolute poverty. The broad correlation
between hunger levels and other aspects of poverty is apparent from the data in Table 3.
In addition, there are virtuous circles coupling progress across a number of indicators; forexample, reducing hunger also reduces vulnerability to disease, and in turn improves
access to livelihoods and food entitlements.
The reduction of absolute human deprivation as discussed here is a necessary
condition for a humane transition to sustainability. However, it may not be sufficient. In
particular, improved social equity within societies may be an important goal in its own

14

Raskin, Gallopin, Gutman, Hammond and Swartright, not merely as one mechanism for eradicating poverty. At issue is the possible link
between social equity and social cohesion — between the perceived sense of fairness inthe distribution of wealth and privilege in a society on the one hand, and allegiance toprevailing social institutions on the other. Inegalitarian societies are likely to besusceptible to relatively high rates of political violence and social instability (Gurr, 1968;
Muller and Seligson, 1987; Muller, 1988), though the detailed empirical findings aredebated (Wang, 1993). We must be satisfied here with simply noting the linkage betweensocial sustainability and distributional equity, and observing that strategies for alleviating
poverty by moderating social inequality, may also enhance social stability.

2.2 Environmental Objectives
In principle, changes to the Earth’s environment that are irreversible on human time scales
are not sustainable, since they diminish the opportunities for future generations. In
practice, there is an inherent tension between such a strong formulation of thesustainability principal and more immediate goals, such as meeting current human needs
and aspirations. Expanding food production may require clearing land for farming orwithdrawing more water from streams for irrigation — putting additional pressure on
natural ecosystems. Providing the jobs, products, and lifestyles of an industrialized, urban
economy will require expanded use of energy — potentially increasing pollution.
The proper balance between the goals of sustainability in the long term anddevelopment in the near term is not easily resolved. The relative weight one puts on therights of future generations and current generations has strong ethical and moral
dimensions. Complicating the issue further is a lack of scientific certainty on many criticalissues: how will the global climate change in response to rising greenhouse gas
concentrations in the atmosphere? How much pressure from human activities canecosystems withstand before collapsing?
The discussion here will focus on a limited set of environmental objectives. As
with the social indicators, international conventions and agreements provide a starting
point for selecting environmental criteria for sustainability. There is broad agreement, forexample, that the stratospheric ozone layer and the global climate should be protected andthat urban and industrial pollution—especially toxic pollution — should be curbed. Thereis agreement that various ecosystems should be preserved so that the services they provide
can continue — from water purification to nutrient recycling to providing habitats fordiverse species of plants and animals — and that future generations can enjoy the natural
beauty and genetic wealth of forests, coral reefs, and the Earth’s biological bounty. Thereis agreement that steps need to be taken to maintain the fertility of soils and prevent
degradation or desertification.
Beyond such agreements, however, there is as yet no consensus on how tomeasure progress toward sustainability, although many different groups have proposed
sets of indicators for this purpose (Munasinghe and Shearer, 1995; Moldan et. al, 1997).
Moreover, lack of data is a serious barrier to making many proposed indicators
operational. The indicators chosen for use in this report constitute a minimum but hardly
sufficient set.
However measured, global environmental trends are not encouraging. Despite

Bending the Curve: Toward Global Sustainability

15

improvements in reducing some local environmental pollution in OECD countries,
pollution levels remain high and are rising rapidly in most developing regions. Pressureson the global commons — the atmosphere and the oceans — are steadily increasing(UNDPCSD, 1997). For example, most marine fisheries are now fished at or above
sustainable levels (FAO, 1991; McGoodwin, 1990) and the incidence of toxic
phytoplankton blooms in coastal waters is rising (WRI, 1994). Pressures on forests, coral
reefs, and other vital ecosystems and on such renewable but finite resources as freshwater
are also escalating (Bryant et al., 1997; Burke and Bryant, 1998).
A transition to sustainability will require reversing these trends. For the purpose of
setting plausible targets for the Policy Reform scenario, this report adopts the point ofview that such a transition should and could be completed in the second half of the 21st
century. This will require abating or reversing, by 2025, the trend of rising pressures fromhuman activity that drive environmental degradation and, by 2050, demonstrating
observable improvements in environmental quality worldwide. These criteria applied toclimate change, for example, would require that global emission of greenhouse gases peakno later than 2025 and that atmospheric concentrations begin to stabilize by 2050, withstabilization completed by 2100.
Indicators and targets are proposed for five environmental issues in Table 5 anddiscussed below. The indicators fall into two broad categories. Climate destabilization,
eco-efficiency, and toxic wastes relate primarily to industrial activities and the demands ofmodern lifestyles. Deforestation, degradation of land, over-exploitation of fisheries, andpotential scarcity of freshwater relate, in addition, to poverty and growing populations.
The targets call for substantial decreases in the environmental pressures from OECDeconomies. At the same time, the targets for developing countries acknowledge that theprocess of development and industrialization must continue in these regions, and generally
propose that developing regions converge gradually toward the decreasing OECD targets.

16

Raskin, Gallopin, Gutman, Hammond and Swart

Table 5. Environmental Indicators and Targets
RegionIndicator

1995

2025

2050

ClimateOECD

CO2 concentration
Warming rate
CO2 emissions
CO2 emissions ratevarious and rising

non-OECD

CO2 emissions ratevarious and risingWorld

360 ppmv

stabilize at < 450 ppmv by 2100
average 0.1°/decade, 1990-2100< 700 GtC cumulative, 1990-2100< 65% of 1990<35% of 1990(< 90% of 1990 by2010)
increases slowing,reach OECD per
energy efficiency rising
capita rates
by 2075

Resource Use
OECD

Eco-efficiency$100 GDP/300 kg

4-fold increase
10-fold increase($100 GDP/75 kg)($100 GDP/30 kg)< 60 tonnes< 30 tonnes
converge toward OECD practices
converge toward OECD per capita values

non-OECD

Materials use/capita
Eco-efficiency
Materials use/capita

80 tonnes
various but low
various but low

Releases of persistentorganic pollutants &heavy metals
Releases of persistentorganic pollutants &heavy metals

various but high

< 50% of 1995

< 10% of 1995

various and rising

increases slowing

Converge to OECD
per capita values

Use-to-Resource ratio

various and risingreaches peak values

Population in water
stress

1.9 billion(34%)

less than 3 billion(<40%)

0.2-0.4 maximum(in countries>.4 in
1995, less than1995 values)
less than 3.5 billion,
begins decreasing(<40%)

various but highvarious but highfish stocks declining

no further deforestation
no further degradation
over-fishing stopped

ToxicsOECD
non-OECD

FreshwaterWorld

Ecosystem Pressure
World

Deforestation
Land degradation
Marine over-fishing

net reforestation
net restoration
Healthy fish stocks

ClimateThe long-term goal for climate, as formulated in the Framework Convention on Climate
Change, is to stabilize concentrations of greenhouse gases in the atmosphere, although
there is as yet no agreement on when and at what concentration levels stabilization should
occur. The approach taken in this report is to first identify a goal for the protection of
ecosystems and then, through a chain of arguments, link the ecological goal to a
restriction of carbon dioxide emissions. The criterion selected here is that warming should
occur no faster than 0.1oC/decade on average between 1990 and 2100, a value that willallow many—but not all—ecosystems to adapt (Rijsberman and Swart, 1990; Hare, 1997).

Bending the Curve: Toward Global Sustainability

17

As will be discussed in Section 3, this implies that the concentration of carbon
dioxide in the atmosphere should stabilize at less than 450 parts per million by volume(ppmv) by 2100. This constraint, in turn, places limits on the cumulative carbon dioxide
emissions from human activities of about 700 billion tonnes of carbon (GtC). The
aggregate global emissions must be allocated to regions and countries. The targets
introduced here take into account equity and burden-sharing considerations in the
allocation of emission rights (see Section 4). Relative to 1990 levels, OECD regions are
assumed to decrease emissions 10% by 2010 (more than the tentative targets ofapproximately 5% adopted in the Kyoto accords) and 35% by 2025. All regions approacha common emissions per capita target by 2075. Though ambitious, the targets arenonetheless required if climate stabilization at reasonably safe levels is to be achieved in
the coming century.
Resource Use
Extracting, refining, manufacturing, transporting, and ultimately disposing of materials is amajor cause of pollution and waste in industrial societies. These materials include themetals and plastics in automobiles, the chemicals that provide the basis for paints,
pesticides, and thousands of other products; and the minerals, fibers, and other natural
resources that comprise everything from clothes to computer chips. As global industrial
activity expands several-fold over the next half century, pollution and wastes and theresulting environmental degradation may also expand, unless there is a transition to acleaner and more efficient — or eco-efficient — industrial system.
To simultaneously increase economic output and reduce environmental stressrequires profound changes in the technological infrastructure of modern societies.
Historically, the throughput of materials into economies has risen with economic growth.
In the sustainability transition, material use and economic scale must be delinked in aprocess sometimes referred to as dematerialization in order to moderate or reduce thepressure on resources and the environment. There are some signs of dematerialization
processes now — the use of energy and various materials has grown less rapidly than
GDP in many industrial countries in recent years. However, the expansion of economic
activity has tended to outpace the improvement in efficiency (e.g., the increase in demand
for road transport has exceeded improvements in auto efficiency) so that aggregate use ofmaterials and energy has continued to increase.
In order to stabilize environmental pressure as economies and populations grow,the flow of material into societies must be controlled through designing more durable
products, reducing waste streams through reuse of materials, and cleaner production
processes. Moreover, the mix of economic activity itself must shift (from resourceintensive to knowledge-intensive activities, for example), and ultimately consumer
lifestyles may need to change, as well. One aggregate indicator of such a transformation iseco-efficiency, which is defined here as the ratio of economic outputs to natural resource
inputs into an economy. Two useful indicators for resource use are the eco-efficiency
indicator, defined here as the ratio of economic output divided by resources required, andmaterials use per capita.
Current values of the eco-efficiency ratio in the OECD regions are typically about

18

Raskin, Gallopin, Gutman, Hammond and Swart$100 GDP per 300 kilograms of materials (Adriaanse et al., 1997).7 Material use percapita ranges between about 45 and 80 tons per person per year. The heterogeneous
character of the material stream hampers the formulation of sustainability goals formaterial efficiency. In practice, the problem of reducing material intensities will need to be
disaggregated into a number of component flows, indicators, and targets in nationalsustainability plans. Nevertheless, we introduce here provisional aggregate targets tosuggest the direction and magnitude of improved eco-efficiency. The summary goal canbe met by varying improvements across the various material components and sectors. A
widely discussed goal is the reduction of resource intensities by a factor of ten (Factor 10
Club, 1995). With this level of improvement in the rich countries, it is possible to prevent
global material requirements from increasing while allowing poor countries to approach anequitable claim on use (Carley and Spapens, 1998).
We take, as a sustainability target for OECD countries, a 10-fold increase in theeco-efficiency ratio by 2050. With this target, $100 of economic output requires only 30
kilograms of natural resources, as reported in Table 5. An ambitious but achievableinterim goal is a 4-fold increase in the eco-efficiency ratio by 2025. Allowing for
economic growth, these targets correspond roughly to a 25% reduction in materials use
per capita by 2025 and an additional 50% decrease by 2050.
Developing economies have eco-efficiencies even lower than in OECD regions, butwith generally much lower values of materials use per capita because the level of output
per capita is much lower. In a scenario that assumes a transition to sustainable
development, developing regions may be able to improve rapidly by adopting and adapting
more efficient technologies and operating practices from developed countries or, in someinstances, leapfrogging to advanced technologies. The sustainability target is thatdeveloping countries converge toward OECD practices in the course of economic growth.
Toxic Substances
Some forms of resource use have such pronounced environmental impacts that more
specific objectives are needed. An important subset is the widespread industrial use andrelease of toxic substances — such as heavy metals and persistent organic pollutants —that can remain in the environment for long periods of time and accumulate to dangerous
levels in soils and sediments, potentially entering the food chain. Long-lived toxic
substances pose a growing threat of uncertain magnitude both to human health and to
ecosystems. International efforts on persistent organic substances are focusing initially on
limits to the production and use of twelve substances (aldrin, dieldrin, endrin, DDT,
chlordane, heptachlor, hexachlorobenzene, mirex, toxaphene, PCBs, dioxins, and furans),
but have not yet reached agreement on specific targets or timetables.
The target adopted here assumes an intermediate target of a 50% reduction, inOECD countries, of all emissions, discharges and losses by 2025 and a 90% reduction by
2050 (allowing some unavoidable emissions related to high priority applications). For
7

Included in the estimates of material requirements are direct inputs of minerals, metals, construction materials, andbiomass from either domestic or foreign sources along with material that is moved or discarded in the process of
extraction and processing.

Bending the Curve: Toward Global Sustainability

19

heavy metals, which tend to accumulate in the soils and sediments, the proposed targets
are the same as for persistent organic pollutants. Use and emissions of toxic substances indeveloping countries are far below OECD levels on a per capita basis but are rising rapidly
and are likely to increase further as industrial activity intensifies. The target set here isthat these increases begin to slow by 2025 and converge toward OECD per capita levels
by 2050.
Freshwater
Freshwater is critical for meeting human needs, supporting economic activity andecosystem preservation. It is a finite and vulnerable resource that must be protected andallocated for these diverse needs. Sustainable development requires the provision of
sufficient freshwater of good quality to growing economies, while protecting aquatic andmarine ecosystems. Water sustainability presents one of the major challenges that humansocieties will face in the coming decades (UNDPCSD, 1997; UNEP, 1997; UN, 1997a).
The natural hydrological unit for water assessment is the river basin. Nevertheless,the global situation can be illuminated by introducing indicators of water stress at thenational level, an exercise that was conducted for the recent Comprehensive Assessmentof the Freshwater Resources of the World8 (Raskin et al., 1997). The basic measure ofwater stress that will be used in this study is the use-to-resource ratio, defined as national
annual withdrawals divided by annual renewable resources. There is no firm relationshipbetween values of this measure and the degree of water stress. Countries differ in theamount of flow lost through floodwater runoff, in the accessibility of surface andgroundwater resources to centers of demand, in down-river claims on water resources,
and in the requirements for ecosystem preservation. Nevertheless, when values of theuse-to-resource ratio exceed 0.4 a country is generally experiencing a high level of water
stress. Indeed, signs of imminent competition between user groups, or between humanand natural requirements, can begin when the ratio is as low as 0.1.
In principle, a valid sustainability goal would be that over the next decades waterpressure decreases in all areas where water scarcity threatens to impede development or
degrade ecosystems. In practice, the momentum of growing water requirements is
unstoppable. Water withdrawals have increased by nearly a factor of three since 1950
(Shiklomanov, 1997), and the continuing momentum of expanding populations,production and food needs will imply continuing growth in water requirements (Section3). Furthermore, if climate change significantly alters hydrological patterns, sustainable
water strategies may be further complicated.
In light of these difficulties, a realistic sustainability goal is that, in river basins
where freshwater has become or will become scarce, withdrawal requirements should peakby 2025. Specifically, in countries where there are indications of freshwater stress (useto-resource ratios greater than 0.1), the target is for withdrawals to stop increasing by
2025. Since this goal allows for increasing use until 2025 water stress will increase.
8

The Assessment was conducted in response to a 1994 call by the UN Commission for Sustainable Development by
UN/DPCSD, FAO, UNEP, WMO, UNESCO, WHO, UNDP, UNIDO, the World Bank, and the Stockholm
Environment Institute.

20

Raskin, Gallopin, Gutman, Hammond and Swart

Indeed, assuming mid-range population growth, the target for 2025 implies that up to 3.0
billion people would be subject to water stress conditions. The goal for 2050 is that useto-resource ratio values remain in the 0.2 to 0.4 range. An exception is the class ofcountries where the use-to-resource ratio is above the 0.4 level currently (there are some17 countries in this category, primarily in the Middle East and North Africa). For thesecountries, the goal is simply that withdrawals in 2050 be less than withdrawals in 1995.
The freshwater targets are rather weak in reference to environmental sustainability
criteria alone, since they recognize the inevitability of continuing water stress in many
regions. As we shall see in Section 4, meeting even these targets is not easy under
Conventional Worlds conditions.
In any scenario for sustainability, freshwater
sustainability requires a major policy focus aimed at increasing water-use efficiency,
reducing losses and enhancing dependable resources.
Ecosystem Pressure
Increasing demands for food, fiber and timber are pressing against the limits of natural
ecosystems. Expanding built environments to satisfy the housing, commercial andtransportation needs of expanding populations and economies compound the problem. To
avoid serious damage, fragile ecosystems need to be protected, deforestation anddestructive logging practices halted, arid lands carefully managed to avoid desertification,
tilled lands managed to avoid erosion or other forms of degradation, and the expansion of
built areas moderated.
Three indicators serve as imperfect proxies for these processes: the rate of
deforestation, the rate of land degradation, and the extent of over-fishing in the major
marine fisheries. Under the Policy Reform scenario, net loss of forested land should bemuch lower than historical rates (or those in the Reference scenario). The target is for
deforestation rates (the net forests lost per year) to reach zero before 2025 in all regions.
This implies the maintenance of critical levels of ecologically rich natural forests. A
growing proportion of the world’s expanding need for wood, paper, and other forest
products should come from plantations or other sustainably managed forests. Bothproductive forests and plantations should increasingly be managed so as to enhance theirecological quality — their capacity to sustain biodiversity and deliver a range of ecosystemservices.
Similarly, land degradation rates (e.g., the land lost to agriculture per year as aresult of chemical or physical erosion) should also slow to zero by 2025. By 2050, forest
cover (and quality) should be increasing, with most forest products coming fromplantations or sustainably-managed forests, and reclamation efforts should be enlarging(and improving) the stock of arable land. Finally, over-fishing should be curtailed so thatthe world’s fish stocks can rebuild themselves to healthy levels.
The environmental criteria for sustainability proposed here are ambitious and posesevere constraints on the Policy Reform scenario. But as with the social objectives
considered above, they may not be sufficient, because they neglect many other importantenvironmental issues. These include the destruction of coral reefs and other fragile
habitats, more subtle pressures on ecosystems such as the growing introduction of invasive
exotic species, and additional local water, air and soil pollution concerns. Moreover,Bending the Curve: Toward Global Sustainability

21

scientific understanding of the Earth system is still fragmentary. It would be unwise to
assume that additional, unexpected, and possibly urgent environmental concerns will notarise.
Future increases in economic activity will tend to aggravate environmental stress.
Indeed, the Reference scenario analysis in Section 3 shows that under conventional
development assumptions and weak environmental and social policies, the indicators ofenvironmental sustainability are likely to drift further and further away from thesustainability targets. Nevertheless, economic development is not only probable, but also
desirable if the social goals for sustainability described earlier are to be met. This defines
the challenge for policy in the transition to a sustainable world.

22

Raskin, Gallopin, Gutman, Hammond and SwartBending the Curve: Toward Global Sustainability

23

3. THE PROBLEM OF UNSUSTAINABILITY
In the previous section, sustainable development goals were expressed in terms of specifictargets for key social and environmental indicators. These provide an operationalframework for defining the quantitative requirements for a sustainability transition and fordevising strategies for inducing such a transition. Naturally, the set of indicators can be
expanded and the targets refined.
Moreover, the global perspective must becomplemented with indicators and targets for guiding sustainable development at regional,
national and local levels.
In the spirit of adaptive management, sustainability criteria will need to be revised
from time to time in response to new information and priorities. Nevertheless, ourprovisional suite of sustainability criteria offer reasonable initial directions for navigating
toward sustainable development — and for weighing how far off course current trends
may be taking us, the topic to which we now turn.

3.1 Reference Scenarios
The tension between the current patterns of world development and sustainability goals
can be illustrated with Conventional Worlds-Reference scenarios. A Reference scenario isa story of a market-driven world in the 2lst Century in which current demographic,
economic, environmental, and technological trends unfold without major surprise.
Continuity, globalization, and convergence are key characteristics of world development— institutions gradually adjust without major ruptures, international economic integration
proceeds apace and the socio-economic patterns of poor regions converge slowly toward
the model of the rich regions.
Reference scenarios are distinguished from Conventional Worlds-Policy Reform
scenarios, the topic of the next section, by the absence of strong and coordinated action
for achieving sustainability goals. Rather, policy focuses heavily on the removal of
barriers to markets at national and international levels (OECD, 1997). In the international
arena, an integrated world economy is promoted through liberalization of trade andfinance. At the national level, the push is for thorough and rapid structural adjustment,
deregulation, and privatization.
A number of trends and forces already in the pipeline drive Reference scenarios
forward. The global population becomes larger, more urban and older. Expanding global
trade, financial transactions and capital flows drive economic growth. The free crossborder flow of goods, services and capital becomes a reality. Transnational corporations
increasingly dominate economic activity and enjoy growing political influence. Spurred bymodern media and information technology, people everywhere and especially the young
are drawn to consumerism. Materialism and individualism spread as core human values.
Despite economic growth, extreme income disparity between rich and poor
countries, and between the rich and poor within countries, remains a critical social trend.
Environmental transformation and degradation is a progressively more significant factor inglobal affairs. Technology is a continuing source of change through advances in
information technology, biotechnology and myriad innovations that change the way we24Raskin, Gallopin, Gutman, Hammond and Swart

produce and consume. The trends are allowed to play out without major changes inpolicy.

3.2 An Illustration
Though many variations are possible, a specific quantitative example can shed lighton the implications of Reference scenarios for sustainability in the next century. By
incorporating conventional mid-range assumptions in our illustration, the main contours ofa business-as-usual future are revealed. In that spirit, demographic, economic andtechnology assumptions are drawn from international assessments wherever possible, e.g.,
United Nations projections and the scenarios of the Intergovernmental Panel on Climate
Change (IPCC, 1990; 1992a).9
A global overview of the scenario is presented in Figure 4. Relative to 1995
values, world population increases by slightly more than 50% by 2050, income (expressed
as GDPPPP per capita10) grows to over 2.5 times the 1995 value, and economic output
more than quadruples. Food requirements almost double, driven by growth in populationand income. Despite higher incomes and greater agricultural output world hunger remains
almost constant, the result of population growth and unequal access to food.
Requirements for energy and water increase by factors of 2.4 and 1.6, respectively.
Resource requirements grow less rapidly than the economy as a whole in the scenario for
two reasons: improving efficiency of use and a gradual shift toward less resource-intensive
economic activities. Global carbon dioxide emissions from energy use, a major driver ofglobal warming, increase by a factor of 2.4 over the scenario period. Increasing land
requirements for agriculture and human settlements leads to a 17% drop in forest area.

9

Technical details on the scenario are presented in Heaps et al. (1998). The Conventional Worlds-Reference
scenario is an update of the Conventional Development scenario (CDS) (Raskin et al., 1996). The CDS waselaborated in separate reports on energy (Raskin and Margolis, 1995), food and agriculture (Leach, 1995), water(Raskin et al., 1995, 1997) and toxic substances (Jackson and MacGillivray, 1995). RIVM/UNEP (1997) assessed
the environmental implications of the CDS, while UNEP (1997) and DPCSD (1997) considered the scenario from a
policy perspective. The base year in the Conventional Worlds-Reference is 1995 versus 1990 in the CDS, andconsiderable additional data and research are incorporated.

10

GDP expressed using purchasing power parity is denoted by GDPPPP, to distinguish it from GDP expressed atmarket exchange rates, GDPMER.

Bending the Curve: Toward Global Sustainability

25

5

1995
2025
2050

Relative to 1995

4
3
2
1
0
Population GDP per
Capita

World
GDP

Food
DemandHungerPrimary
EnergyWater

CO2Emissions

ForestArea

Figure 4. Global Overview of the Reference Scenario

The global results mask considerable regional variation in economic, social andenvironmental patterns. The scenario analysis in this report is conducted for the ten major
regions shown in Figure 2. Regional results are collected in the Annex as a series of tables
and graphs. The population assumptions in the Reference scenario are summarized on
Sheet D-1. In these mid-range projections, world population approaches 10 billion during
the middle of the next century (UN, 1997) with nearly all the growth occurring in thedeveloping regions. Of the net increase of 3.7 billion people by the year 2050, only 2% isin the OECD regions. The populations in Eastern Europe and the former Soviet Union
actually decrease slightly in the scenario. The world continues to become more urban as
the population in cities rises from 2.5 billion in 1995 to 6.7 billion in 2050 at which time
72% of the world population will live in cities (Sheet D-2).
Economic trends based on mid-range assumptions (IPCC, 1992a) are highlighted
in Sheets E-1, E-2 and E-3. Global GDPPPP increases from $33.4 trillion in 1995 to over$145 trillion in 2050, an average growth rate of 2.7% per year. The higher growth rate indeveloping region economies, about 3.4% per year, causes their share of world product torise from about 40% to 60%. The immense scale of the economy implied by theseassumptions is illustrated by the case of China+ where the GDPPPP in 2050 is greater than
the whole of the OECD today.
In all regions, GDPPPP growth exceeds population growth, so GDPPPP per capita(or “income”) increases in every region (see Sheet E-3). The projections show a gradualconvergence of the developing regions toward the industrialized ones in the sense that theratio of average income of the OECD regions to that of the non-OECD decreases from
6.5 to 5.5. At the same time, the absolute difference between OECD and developing
regions increases from about $17,000 per capita in 1995 to $47,000 per capita by 2050.
In general, the scenario is one of wide prosperity by mid-century in which developing
regions approach standards of living enjoyed in Western Europe circa 1980 while OECD
incomes soar, reaching $73,000 per capita in North America.

26

Raskin, Gallopin, Gutman, Hammond and Swart

As the scale of economic output grows in the scenarios, the structure of economic
activities changes. The share of GDP from agriculture continues to decline, a pattern longassociated with the process of industrialization and development. Moreover, as
consumption patterns shift toward greater emphasis on services and light manufacturing,
the share of industry in economic output declines. These patterns are reflected in Sheet E2. Finally, the composition of industrial production from heavy industry decreases in the
scenario reflecting de-materialization trends in advanced economies (Williams et al., 1987;
Bernardini and Galli, 1993). Specifically, in OECD regions output per capita of resourceintensive industries remains constant (non-ferrous metals, paper and pulp, and chemicals)
or decreases by about 10% (iron and steel and non-metallic minerals). Non-OECD
regions converge toward these patterns as GDPPPP per capita increases.
The economic expansion assumed in the scenario drives energy demand higher (seeSheet En-3). The energy needs in developing regions grow by a factor of 3.7, reaching
60% of world demand by 2050 compared to 40% today. By the end of the scenario
period, the energy requirements of China+ approach those of North America, while theenergy requirements of South and South East Asia exceed them. While significant, energy
growth is less than economic growth, a result of the changing composition of economic
activity and the continued penetration of more energy-efficient devices and practices. Putanother way, aggregate energy intensity (the ratio of energy requirements to GDP)decreases globally from 11.5 to 6.4 MJ/$GDPPPP between 1995 and 2050 (Sheet En-1).11
While fossil fuels continue to dominate in energy production (see Sheet En-2), there is anotable absolute expansion in renewable and nuclear energy, by factors of 2.2 and 2.5,
respectively.12
Population increases and diet changes drive the near doubling of world foodrequirements. The Reference scenario assumes continuity with past trends. Dietary
patterns adjust with rising incomes, including greater food consumption in developing
regions, with an increasing share of calories derived from animal products (Sheet F-1).
The demand for fish and other seafood increases in the scenario from roughly 100 million
tonnes per year currently to 170 million tonnes by 2050 (Sheet F-3). Assuming thatmarine resources, which are already overtaxed, remain steady at about 85 million tonnes,
this requires substantial expansion of aquaculture (Sheet P-9), which adds to theagricultural requirements for feed.
On the production side, the scenario shows increased agricultural output in all
regions. In the OECD regions as a whole, production of animal and crop products
increases by almost 40% between 1995 and 2025 (Sheets F-2 and F-4, respectively). In
Eastern Europe and the former Soviet Union, production rebounds from the collapse
during the 1990s and then expands, as these regions become significant agricultural
exporters. In Africa and the Middle East, populations nearly triple by 2050 and food
11

Energy units are defined in the appendix.

12

To convert renewable energy to primary energy equivalents, this study uses the International Energy Agency
convention, which expresses hydropower and non-biomass renewables in their electrical energy equivalent(assuming 100% conversion efficiency). Since other studies (e.g., WEC/IIASA, 1995) express these as thermalenergy equivalent values, which increases the reported values by about a factor of 3, care should be taken incomparing results.

Bending the Curve: Toward Global Sustainability

27

requirements go up even faster due to increased caloric intake and more reliance on meatproducts. To meet the growing demands, agricultural production more than triples andimports rise — from about 37% of total requirements in 1995 to almost 44% by 2050 in
the Middle East and from 12% to almost 15% in Africa. Both China+ and South andSoutheast Asia maintain self-sufficiency in rice production, although rice declines as afraction of the total diet in these regions in preference to other grains, meat and highervalued crops.
Underlying the increase in production in the scenario are assumptions on yield
improvements, and expansion of pastureland and cropland. The scenario is broadly
compatible with the results of recent assessments of the prospects for world agriculture
over the next two decades such as those of the Food and Agriculture Organization(Alexandratos, 1995) and the International Food Policy Research Institute (Rosegrant, etal., 1995). It shares their optimism of sustained improvement in agricultural performance.
Yields gradually increase in all regions (Sheet F-5), the result of greater reliance on
irrigated farming (Sheet F-7), and assumed improvements in plant varieties and farm
practices. Global average cereal yields increase by about 1.3% per year between 1995 and2025 and 0.8% per year between 1995 and 2050. While these increases are substantial,
they are less than the 2.2% cereal yield improvement per year between 1961 and 1994, inpart due to constraints on the expansion of irrigated farming (Leach, 1995). In addition to
the intensive increases in yields, farmland expands extensively into forests and pasturelands (Sheets F-6 and P-6). The expansion is checked by the reduced availability ofsuitable land, constraints on irrigation expansion due to rising costs and limited freshwater
resources and competition for land-use. Globally, farmland increases some 10%, mostly in
Africa. Irrigated farm area increases slowly from 250 to 288 million hectares, remaining ataround 18% of total farmland throughout the scenario (Sheet F-7). In addition, thenumbers of harvests per year (“cropping intensities”) gradually grow, further increasing
farm output per area (Sheet F-5).
On the demand side, the requirements for food and other agricultural products risewith income. At the same time, higher-valued foods are slowly substituted for cereal
staples as incomes rise. An exception is in North America, where health concerns
continue to cause a gradual decline in reliance on animal products. In this picture, enoughfood can be produced to feed growing populations, a conclusion that is subject toimportant caveats: sufficient water must be available, serious land degradation andagrochemical pollution must be avoided, and trade flows from rich to poor regions must
not face impediments. Finally, the problem of access to food among the very poor willremain and hunger will persist, as we discuss in Section 3.3.
The issue of water sufficiency and quality requires special attention. During the
1990s, awareness that water may be a limiting factor for development has grown, alongwith the recognition of water as a finite and fragile resource for ecosystem maintenance.
The character of the looming water problem and strategies for the future were developedin a series of international meetings and studies including the Rio meeting (UNCED,
1992), the Comprehensive Assessment of the Freshwater Resources of the World (SEI,1997) and the United Nations Commission on Sustainable Development (UNCSD, 1998).

28

Raskin, Gallopin, Gutman, Hammond and Swart

Water use increased four-fold between 1940 and 1990, driven by irrigation
expansion, population growth, and economic development (Shiklomanov, 1993). As
water requirements rise, so does competition over the entitlement to finite water
resources. The competition takes multiple forms depending on the conditions at the river
basin level — between the farm and the city, between environmental and human use, andbetween upstream and downstream riverine countries.
In the Reference scenario, water requirements for development continue toincrease driven by growing populations, economies and agricultural requirements. Global
water requirements grow by a factor of 1.6 over the scenario period, and in developing
regions by factors ranging from 1.7 in China+ to 2.2 in Africa (Sheet P-1). While
substantial, the pace of water demand growth is much slower than was experienced overthe past 50 years, an average growth rate of about 0.9% per year versus about 2.5% peryear historically. There are three reasons for the moderation in growth rate: slower
expansion of irrigated lands, shifts in the composition of economic activity toward lesswater intensive sectors, and greater efficiency in water use. The changing sectoral patternof water use is summarized in Sheet P-2. Note that about 70% of current global
freshwater withdrawals are for irrigation, decreasing to about 60% by 2050.
Nevertheless, the absolute requirements for irrigation water increases by almost 50% as
agricultural land under irrigation gradually expands (Sheet F-7), increasing by 15% by2050, and more water is taken up by higher yielding plants (Raskin et al, 1997).

3.3 Environmental Risk
The Reference scenario presents a picture of increasing resource use and environmentalpressure. By comparing these patterns to the sustainability goals introduced in Section 2,
the scenario provides a benchmark for gauging — in the absence of major course changes
in technology, demographics and consumption patterns — the degree and character ofenvironmental unsustainability.
3.3.1 Climate change
The proposed sustainability goal is to limit human-induced temperature change to no morethan 0.1° per decade, or a cumulative change of about 1.1° between 1990 and 2100.13
The rising temperatures are caused by increases in the atmospheric concentration ofgreenhouse gasses, which trap some of the heat generated by sunlight falling on the earth’s
surface. As a consequence, eventual stabilization of average global temperature will
require stable levels of greenhouse gasses in the atmosphere. These concentrations, inturn, are determined by the rate at which the gasses are emitted to and absorbed from theatmosphere as a result of both human activity and natural processes.
13

Climate models relate changes in atmospheric concentrations of greenhouse gasses to estimates of changes inequilibrium temperature from pre-industrial levels. Due to inertia in the climate system, it may take several
decades to reach such equilibrium. The target of experienced temperature changes of about 1.1° (all temperatures
are reported for the Celsius scale) between 1990 and 2100 corresponds roughly to a committed change of about 1.5° over that period. Assuming greenhouse gas concentrations stabilize in 2100, and including the estimated 0.5°
increase already experienced between pre-industrial times and 1990, the total change due to human activities underthese conditions would be ultimately about 2°.

Bending the Curve: Toward Global Sustainability

29

Are climate goals met in the scenario? The answer to this question requires
several stages of analysis. First, the sustainability goal, expressed above in terms oftemperature change, must be linked to a corresponding level of atmosphericconcentrations of carbon dioxide and other greenhouse gasses.
Second, theconcentrations must be related to an allowable cumulative quantity of CO2 emissions fromhuman activity. Finally, this “carbon budget” for meeting the sustainability goal must becompared to the emissions computed for the scenario. In the Policy Reform scenario
discussed in Section 4, the goal is imposed on the scenario and the global carbon emission
budget is allocated to regions (and ultimately countries) on the basis of economic,
technological and equity considerations, and political feasibility.
In order to link equilibrium CO2 concentrations to temperature change,
assumptions must be made about the contributions of greenhouse gasses other than CO2.
Also, the estimated temperature change depends upon the assumed value for the climate
sensitivity parameter — the equilibrium temperature change associated with a doubling of
CO2 concentration. The climate sensitivity is estimated by the IPCC to lie within the range
1.5° to 4.5° (IPCC, 1996). Assuming a climate sensitive of 2.5°, global mean temperatureis estimated to increase by about 1.0° between 1990 and 2100, assuming an equilibrium
CO2 concentration of 450 ppmv and a range of non-CO2 gas emissions profiles (IPCC,
1997). This 1.0° change is close to the sustainability goal of 1.1° temperature change overthe same period. This suggests an equilibrium concentration target of about 450 ppmv asa reasonable goal for policy.
The relationship between atmospheric CO2 concentrations and cumulativeemissions is summarized in Figure 5. Shown in the figure are long-term equilibrium
concentrations for atmospheric carbon ranging from 350 parts per million by volume(ppmv) to 750 ppmv and the corresponding cumulative carbon emissions from humanactivity between 1990 and 2100 (IPCC, 1995). The carbon sources are primarily fromenergy combustion and net biomass loss through deforestation and land clearing. The
uncertainty ranges reflect differences in the outputs of carbon cycle models, which
simulate the interactions between atmospheric, oceanic and terrestrial systems. The policy
target of 450 ppmv corresponds to a cumulative carbon emissions allowance between
1990 and 2100 in the 640-800 GtC range.

30

Raskin, Gallopin, Gutman, Hammond and Swart

Cumulative CO 2 Emissions to 2100
(GtC)

1,500
1,250
1,000
750
500
250
0
350

450
550
650
Atmospheric CO 2 Concentration (ppmv)

750

Figure 5. CO2 Emissions to 2100 Corresponding to Different Stabilization Concentrations
Source: IPCC (1995)

We stress that the goal of 450 ppmv is conservative in that it accepts thatconsiderable global change is inevitable. Also, if the higher values in the climate sensitivity
range (that is, 4.5°) turn out to be more accurate, an additional 0.5° of climate change
would occur and the sustainability target would be exceeded. Stronger goals —stabilization at 350 ppmv or even a return to the pre-industrial level of 280 ppmv — arearguable from an environmental sustainability perspective.14 But given the recalcitrance
to date among key countries for adopting vigorous greenhouse gas abatement strategies, itappears that achieving such ecologically driven goals would indeed require a Great
Transition (Section 1). Within the Conventional Worlds framework, the focus of the
scenarios considered in this study, the 450 ppmv goal presents a strong but realizable
challenge for policy.
The Reference scenario does not meet the target. Annual carbon emissions areplotted in Figure 6 along with emissions in the IPCC IS92 scenarios. The Reference
emissions trajectory tracks closely the mid-range IS92a scenario. This correspondence isdue to the underlying compatibility of demographic, economic and technologicalassumptions in the two scenarios. Assuming that the Reference scenario continues tofollow the IS92a path after 2050, cumulative carbon emissions between 1990 and 2100
14

According to Azar and Rodhe (1997): “If the climate system is sensitive to CO2 increases in the IPCC upper
range, then a CO2 concentration of only 550 ppmv will be sufficient to yield a change in average global
temperature of a magnitude approaching that which occurs during a transition to an ice age; it appears that to keep
the changes in global temperature within the range of natural fluctuations during the past millennium, the climate
sensitivity has to be low and the atmospheric CO2 concentration has to be stabilized at around 350 ppmv.”

Bending the Curve: Toward Global Sustainability

31

would be about 1500 GtC (which includes about 80 GtC from tropical deforestation).
This is about double the 640-800 GtC cumulative emissions to 2100 required to stabilize
concentrations compatible with the sustainability goals. The total temperature change
between 1990 and 2100 ranges from 1.4° to 2.9°, depending on the value of the climate
sensitivity parameter (IPCC, 1997), exceeding the sustainability target of 1.1°.

40

CO2 Emissions (GtC/year)

35

Cumulative =2190 GtC

Reference

30

IS92e
1830

25
IS92f
20

1500
1430

IS92a

15

IS92b

10

IS92d

980

5

IS92c

770

0
1990

2010

2030

2050

2070

2090

Figure 6. Industrial CO2 Emissions in Reference and IPCC Scenarios
Source: CSIRO, 1994; IPCC, 1996
Note: Emissions from land clearing included in IPCC scenarios (about 80 GtC in IS92a)

Global patterns of carbon emissions in the Reference scenario are reported byregion on Sheet P-4. Annual emissions more than double over the 1995-2050 period.
The share of emissions from OECD regions drops from about 50% to 30% over thistimeframe as developing region emissions soar, driven by population growth and the longrange economic and technological convergence assumptions in the scenario. Thechanging regional composition of emissions is striking. In 1995, North America is
responsible for 1.5 GtC emissions, accounting for 25% of the global total. During the first
decades of the next century, two developing regions — China+ and South and Southeast
Asia — surpass North American emissions. Emissions in Africa increase by over a factorof eight in the scenario.
Despite the rapid rise in developing country emissions in the Reference scenario,
substantial inequities remain. Emissions per capita grow much faster in developing
regions so there is some convergence — the ratio of the value in North America to that in
Africa is 22 in 1995 but falls to 9 by 2050 (Sheet P-4). Nevertheless, large absolutedifferences in emission loads persist throughout the scenario period, another expression of
the slow process toward the amelioration of current disparities in economic development

32

Raskin, Gallopin, Gutman, Hammond and Swart

the Reference scenario. Reduction in regional differences in emission rates is an elementof the normative goals defining the Policy Reform (Section 4).
3.3.2 Fossil Fuel Reserves
The question of the adequacy of fossil fuel resources over the long term is closely related
to the issues of climate change and sustainable energy. Since the oil crises of the 1970s,
concern over petroleum reserve limits has vanished from the newspapers and dropped off
the policy agenda. Prices have dropped, new oil fields have been brought into production
and advanced techniques have increased the recovery rates at existing fields. At existing
rates of extraction, proven reserves are adequate for 40-50 years. Despite the comforting
oil scene today, from the long-term perspective of the Reference scenario, with rapid
growth in global demands, the oil problem is likely to re-emerge. Estimates of ultimately
recoverable reserves — the total of previously extracted, proved and undiscovered
reserves recoverable — have not increased greatly since the 1960s (Masters et al., 1990).
Rather, estimated additional reserves have been gradually reclassified as proved reserves.
Remaining proved and estimated undiscovered oil reserves are approximately 1600
billion barrels (WEC, 1995; Masters et al., 1994), of which 1000 billion barrels is proved.15
As the demand for oil grows in the scenario, these reserves would be depleted around2035 (see Sheet En-5). However, according to standard theories of oil exploitation,
production decreases may occur much sooner, perhaps as early as 2010 when half of the
global resource will have been extracted (Hubbert, 1956; Mackenzie, 1996). The
geopolitics of oil becomes a resurgent theme in the scenario as industrialized regions
increasingly depend on imports from the Middle East and Latin America (Swart, 1996).
Of course, the gap between oil supply and demand will be closed in practice.
Supply might be increased by vast new discoveries of conventional sources, though this is
not likely, or by unconventional options such as tar sands and oil shale. However,
exploitation of unconventional resources is likely to pose severe environmental problems
and to be much more costly than conventional crude.16 On the demand side, the pressureon oil resources could be curtailed through massive fuel switching and efficiency
improvements, options taken up in the Policy Reform scenario (Section 4). In the
Reference scenario, the heightened risk of economic vulnerability and international conflict
challenges the continuity and growth assumptions of the scenario.
Global proved and undiscovered natural gas reserves are estimated at about 1015 EJ (WEC, 1995; Masters et al. 1994), roughly 300-400 trillion cubic meters. In the
Reference scenario, cumulative requirements for natural gas between 1995 and 2050 are
about 200 trillion cubic meters, implying growing stress on reserves, though not as severe15

A recent critique of industry figures suggests that remaining reserves may only be about 1000 billion barrels(Campbell and Laherre, 1998), far less than the 1600 billion barrels assumed here. On the other hand, anotherrecent study (WEC/IIASA, 1995) assumes nearly 2100 billion barrels, but these are based on “P05% estimates”,
i.e., reserves that are only 5% likely to be met or exceeded.

16

Natural gas hydrates (icy substances composed of methane and water) are a potentially enormous source of fossil
energy, perhaps more than 8500 billion barrels of oil equivalent (WEC/IIASA, 1995), but would also be
economically and environmentally costly.

Bending the Curve: Toward Global Sustainability

33

as petroleum (Sheet En-5).17 Coal reserves remain abundant despite the increasing
demands in the scenario; environmental concerns are the limiting factor on coal use.
3.3.3 Nuclear energy
The long-term role of nuclear power in addressing the climate problem and a transition tosustainable energy use is a key uncertainty for the future. The nuclear power industry
enjoyed an astonishing boom from its inception in the mid-1950s to the late 1980s. In
1995, nuclear reactors accounted for 17% of world electricity production. But in recent
years, the industry stagnated, with new construction starts barely keeping pace with plant
retirements. Both the rising costs of nuclear energy and public concerns about nuclear
safety have plagued the industry and brought it to a standstill.
Nevertheless, as world electricity demand grows, there will be great pressure toturn to the nuclear option, a relatively abundant and virtually CO2-free resource (OECD,1997). In the Reference scenario, global electricity demand grows by a factor of four
between 1995 and 2050, and more than a factor of ten in developing regions. In thiscontext, nuclear installed generating capacity more than doubles by 2050. All of thegrowth is in non-OECD countries, where nuclear energy expands by a factor of 3.5. The
scenario assumes that nuclear cost and safety concerns are mitigated, perhaps through a
new generation of modular units with advanced designs. The environmental and resource
problems associated with growing demands for fossil fuels help to revive the nuclear
alternative.
However, serious challenges to the sustainability of nuclear energy will persist.
First, another Chernobyl-like accident could trigger renewed public outcry for nuclear
moratoria. Second, the need to contain highly toxic radioactive waste for tens of
thousands of years is an imposition on future generations that does not square easily withthe basic sustainability notion of increasing, not limiting, future options.
Finally, the most vexing problem for nuclear energy may be the link between
civilian commercial power generation to issues of peace and security. Civilian nuclear
programs have fostered nuclear weapons development in a number of countries.
Moreover, an expansion of the global commerce in reactor-grade fuel and plutonium, as
envisioned in the scenario, would increase the danger of the diversion of these materials tonuclear weapons fabrication and to nuclear proliferation. These problems could intensify
as the once-through nuclear technology that dominates today gradually gives way to aclosed-cycle process, in which plutonium is recovered from spent fuel in reprocessing
facilities and resold on global markets. With the growth of nuclear energy comes therising risk that extremist social movements and rogue states gain nuclear weapons
capability. The increased threats to domestic and international security, and the danger ofregional conflicts spiraling out of control, could compromise the institutional stability ofthe scenario.

17

Rogner (1996) suggests that an additional 820,000 EJ unconventional resources (mainly in the form of clathrates)
can be made at least partly available.

34

Raskin, Gallopin, Gutman, Hammond and Swart

3.3.4 Toxic Waste
The material and chemical flows underlying a modern industrial economy are immenselycomplex and are neither well tracked nor well understood. Nearly 100,000 synthetic
industrial chemicals contribute to the toxic and hazardous loads on the environment. The
pathways into the environment of hazardous chemicals and heavy metals are from mineral
extraction and refinement processes, emissions at industrial production facilities, anddissipative losses from materials embodied in products. While some of the substances may
not pose environmental or toxicological threats, there is insufficient scientific information
for assessing about 90% of them (NAS, 1984).
Estimates of current and future values under Reference scenario conditions arecollected in Sheet P-10 (Heaps et al., 1998). Assuming that current practices and levels of
regulatory control persist in developed regions and that developing regions graduallyconverge toward these practices, toxic emissions by 2050 are about three times higher
than current levels. There is a roughly five-fold increase in the developing regions as awhole and an almost two-fold increase in the OECD regions. These increases are
somewhat less than the growth in the global economy, due to structural shifts in outputs
and the playing out of current policies.
International efforts to limit waste production remain at current levels in the
Reference scenario and are unable to initiate the “clean production” revolution required tocounteract the growth in the scale of production and consumption. By contrast, oursustainability goals for persistent organic pollutants (POPs), heavy metals and radio-active
wastes are reductions of 50% in 2025 and 90% in 2050 in OECD regions, withconvergence toward the implied emission intensities in developing regions.
3.3.5 Water resources
In the Reference scenario, the pressure on freshwater resources grows more severe in all
regions. The situation in Middle East countries, which is already grave, deteriorates, while
problems deepen in Eastern Europe, China, Africa, and in various river basins elsewhere.
Despite the much greater water-use efficiencies assumed in the scenario, population andeconomic growth drive up overall requirements. Of course, regional analysis is far too
aggregate for water assessment and can mask problems at the basin level. Therefore, theevaluation of water sustainability for the scenario has been conducted on a national basis(Raskin, et. al., 1997).
In 1995, some 1.9 billion people lived in countries experiencing some water stress(use-to-resource ratio greater than 0.1) and of these nearly one half billion were in highstress areas (ratio greater than 0.4).18 An additional 1.6 billion people had sufficient wateron average, but the supply was unreliable due to variations in precipitation, dependence on
import flows from external sources, or inadequate infrastructure such as storage capacity.
In the scenario, the population experiencing some water stress rises to about 4 billion by
the year 2025, with 2.3 billion under high stress. In 2050, nearly 5 billion people contend
18

For each country, the population in water stress is assumed to rise from zero to 100 percent as the use-to-resource
ratio increases from 0.1 to 0.4, with high stress defined as a use-to-resource ratio greater than 0.4 (Raskin et al.,1997).

Bending the Curve: Toward Global Sustainability

35

with water stress, with 3 billion of them, over half of the total, in areas of high stress(Figure 7). Regional water stress indicators are summarized on Sheet P-3, while regionaland sectoral breakdowns of water withdrawals are summarized on Sheets P-1 and P-2
respectively. The Middle East, already short of water today, faces a deepening watercrisis, while huge populations in the Asian regions move toward high water stress levels.
Africa is another region with increasingly intense water “hot spots.”
5

SevereStressModerate
Stressbillions of people

4
3
2
1
0
1995

2025

2050

Figure 7. Population in Water Stress

Finally, the climate change impacts of the scenario may exacerbate the water
situation in vulnerable areas (Alcamo et al., 1997; Morita et al., 1995). Water scarcity
would also pose increasing security risks in shared water basins, such as in the Middle
East (Wallensteen and Swain, 1997). Finally, competition for scarce freshwater resources
would hamper attempts to increase access to safe drinking water and sanitation. Far frommeeting our sustainability criteria, water scarcity may be a limiting factor on the robust
population and income growth of the Reference scenario.
3.3.6 Land Resources and Biodiversity
In the course of development, human activity alters the landscape. The dynamics of landchange are complex, depending on settlement patterns, agricultural practices, economic
growth and natural resource industries. Several key factors drive land change in the
Reference scenario:•

Settlement area. The so-called “built environment” expands onto agriculture, forest,
pasture and other land types as populations grow (Sheet D-1) and economies
modernize. The settled area per person has been increasing historically and currently
is estimated at 0.13 hectares per capita in North America and 0.06 hectares per capita
in Western Europe and Pacific OECD (Heaps et al., 1998). In the scenario, thegrowth is assumed to abate as area per person gradually approaches 0.15 and 0.07
hectares in North America and the other OECD regions, respectively. Africa and36Raskin, Gallopin, Gutman, Hammond and Swart

Latin America, where population densities are relatively low, converge gradually
toward average OECD values, while other developing regions are assumed toconverge toward the more compact Western European standards (Sheet P-7). With a
global increase of some 345 million hectares (Sheet P-6), the expansion of settled
areas places significant pressure on agricultural lands and valued ecosystems. Settled
areas expand into agriculture, forest, rangeland or other land types with the sharesvarying from region to region (Heaps et al., 1998).
•

Pasture and Rangeland. The utilization of land for grazing livestock changes in the
scenario for several reasons. First, total output of meat products grows, primarily inresponse to population growth and diet changes, and to a lesser extent due to tradeadjustments in these products. Second, the share of livestock in feedlots continues thehistoric pattern of increasing with economic growth, thereby moderating the increased
pressure on grazing lands. These patterns are reflected in the figures reported on
Sheet F-2. Finally, in developing regions the intensity of livestock production (output
per hectare) increases in the scenario on the assumption that changing pasturing
practices and improved livestock characteristics accompany economic development
and scientific advances (e.g., related to biotechnology). Despite the increased intensityof use, grazing areas increase in all developing regions (Sheet P-7). The increase is at
the expense of cropland, forest and marginal land. Due to substantial uncertainty incurrent data on all these factors, changing pastureland requirements in the scenario can
only be considered indicative of trends.

•

Crop land. New farmland comes from potentially cultivable land under forest,
pasture and rangeland (Sheet F-8), with the shares varying by regions (Heaps, et al,1998). In addition, in some regions agriculture expands onto marginal land, which will
require considerable inputs and careful management.

•

Land degradation. Unsustainable land-use practices can lead to various forms ofland degradation including wind and soil erosion, soil compaction, waterlogging,salinization and nutrient depletion. Global land degradation of various degrees ofseverity has been estimated at 2 billion hectares in the last fifty years, or nearly aquarter of agricultural land, forest, woodland and pastureland (Oldeman et al., 1991).
Much of the effect of the degradation is reflected in diminished yields anddeforestation assumptions. The quantity of land so severely degraded that it isremoved from agriculture production has been reported at from 5-10 million hectares
per year (Kendall and Pimentel, 1994) though the basis for these estimates is weak andthey may be high (Alexandratos, 1995). In the Reference scenario it is assumed thatabout 3 million hectares per year are withdrawn from agricultural production globally
due to severe land degradation.

The combined effect of these various factors is to alter regional land cover. In
particular, the area under forest decreases by nearly 700 million hectares during the 1995
to 2050 period, a loss of about 17% of existing forest stands. Deforestation by region isreported in Figure 8. The Reference scenario forest loss rate is compatible with recent
trends in which over 200 million hectares were lost between 1980 and 1995 (FAO,
1997b). The scenario is consistent with other “business-as-usual” scenarios, which

Bending the Curve: Toward Global Sustainability

37

generally suggest that deforestation persists during the first decades of the next century(Alcamo et al., 1995).
2,500

S+SE Asia
Latin America
China+
Africamillion hectares

2,000

1,500

1,000

500

0
1995

2025

2050

Figure 8. Forest Areas in Developing Regions in the Reference Scenario

As a result of the competing pressures, land change in general, and deforestation inparticular, is substantial under Reference scenario conditions. For example, the target forenvironmental sustainability (Section 2) of decreasing annual rates of deforestation toward
zero by 2025 and reforestation after that point are severely violated. Instead,deforestation rates are about 12 million hectares per year throughout the 1995-2025
period and, rather than reversing, continue after that period at about the same rate.
Moreover, the maintenance of protected forest areas, let alone their expansion, would not
be easy in the scenario with its free market emphasis and avoidance of government
intervention. With respect to sustainable use of land resources — and biodiversity
preservation that is closely correlated with the maintenance of ecosystem integrity — theReference scenario fares poorly.

3.4 Persistent Poverty
The Reference scenario presents a picture of increased pressure on resources and theenvironment. If the environmental criteria for sustainability are to be met, policies will beneeded to induce alternative patterns of resource use and to stimulate the development anddeployment of better technologies. The kinds of adjustments necessary to meetenvironmental goals will be taken up in the Policy Reform discussion (Section 4).
The Reference scenario also is problematic with respect to the social goals
introduced in Section 2. We focus on the changing levels of poverty in the scenario andthe manifestation of poverty in the form of chronic hunger, lack of clean water and othershortfalls in the provision of basic needs. The number of people in poverty in any country
will depend on several factors. On the one hand, all else equal, population growth in the
scenario (Sheet D-1) will increase the absolute numbers of impoverished people. On the38Raskin, Gallopin, Gutman, Hammond and Swartother hand, the rapid growth assumed for average income will tend to reduce poverty(Sheet E-3). The third key factor is the manner in which income is distributed over the
population. If the trend in income distribution is toward more egalitarian distributions, theeffect will be to reduce poverty. Increasing inequality will exacerbate poverty levels.
To proceed, we must further examine income distribution patterns. National
income distributions are typically skewed, with most of the population concentrated atlower incomes. A useful measure of the degree of inequality in a given society is the Gini
coefficient. The Gini coefficient is defined with reference to the Lorenz curve, a plot of
the fraction of total income held by a given fraction of the population, beginning with thelowest-income populations (see Figure 9). In a society where everyone has the same
income, the Lorenz curve would be a straight line, while in actuality the curves take theconcave form as illustrated in the figure. The Gini coefficient, a measure of the deviationof an actual income distribution from a condition of perfect equality, equals the ratio of theareas A/(A+B). The coefficient ranges from values of zero (complete equality) to one(extreme inequality).

1

0.6

0.4

A
B

Cumulative income fraction

0.8

0.2

0
0

0.2

0.4

0.6

0.8

1

Cumulative population fraction

Gini coefficient = A/(A+B)

Figure 9. The Lorenz Curve and Gini Coefficient

The degree of income inequality found in the world today varies widely fromcountry to country. Gini coefficients by region are presented in Sheet S-1, computed byaveraging country level coefficients weighted by population (Heaps et al., 1998). Notethat the values of the Gini coefficient range from around 0.30 to over 0.50.
The trends in the income distribution in the Reference scenario are based on theassumption of a general pattern of regional convergence toward industrial country

Bending the Curve: Toward Global Sustainability

39

standards, in a context of economic globalization and weak social policies to address
poverty and inequality. For thirty years, inequality has been increasing in the UnitedStates as redistributive social policies have eroded (Figure 10). In the scenario, income
inequality continues to increase in the United States, but at half the historic rate as policy
shifts play out. The Gini coefficient reaches 0.50 in 2050, with other countries graduallyconverging toward this pattern (Sheet S-1). The general trend is one of increasing Gini
coefficients, with the largest increases occurring in the “transitional” regions of Eastern
Europe and the former Soviet Union.
0.47

Gini Coefficient

0.45

0.43

0.41
Gini = 0.0023 x (year -1970) + 0.387
0.39

0.37
1965

1970

1975

1980

1985

1990

1995

2000

Figure 10. Historical U.S. Gini Coefficients
Source: U.S. Census (1997)

The assumptions on regional population, economic growth and distribution
provide a picture of changing income distributions in the course of time. This is illustrated
for the United States and China in Figure 11.19

19

Income distributions are approximated throughout this study by a lognormal curve:2
 1
exp  − 2 (ln(i / i ave ) + σ 2 2) 
2
σ
2π σi


where p ( i ) ⋅ ∆i is the number of people with incomes between i and i + ∆i , P is total population, iave is the mean
income and σ characterizes the degree of income inequality. The Gini coefficient is an increasing function of σp (i ) =(Heaps, et al., 1998).

P40

Raskin, Gallopin, Gutman, Hammond and Swart

Income Distribution

1995

United States
2025
2050

0

10,00020,00030,00040,00050,00060,00070,00080,000$ GDP per capita
1995

Income Distribution

China

2025
2050

0

2,000

4,000

6,000

8,000

10,00012,000$ GDP per capita

Figure 11. Changing Income Distributions

We turn our focus now to hunger levels in the scenario — the changing pattern ofchronic undernourishment. In this study, hunger serves as a proxy indicator for poverty(see Section 2). The approach is to define a “hunger line,” the income at which a family orindividual is just barely able to meet the minimum dietary requirement for a normally
active life (Heaps et al., 1998). This is analogous to the “poverty line,” a minimum
income or expenditure level below which a person or household is barely able to satisfy
basic needs requirements. For the poorest countries, the poverty line used by the WorldBank is about $525 per person annually in today’s dollars (PPP). The relationshipBending the Curve: Toward Global Sustainability

41

Income Distribution

between the number of hungry people in a region and the hunger line is shown in Figure
12.

# of Hungry

Hunger Line (yH.L.)

IncomeFigure 12. Relationship Between Number of Hungry and the Hunger Line

Survey data on hunger and income distribution are used to compute the current
values of the hunger line (Heaps, et al., 1998). The hunger line cut-off tends to increase
as countries develop (Figure 13).20 This may be due to decreased access to informal
sources of food — informal food gathering is a form of income that is not well-captured inhousehold surveys. Furthermore, as countries grow wealthier, more must be spent on
non-food items even by those just able to acquire the nutrients they need for a normally
active life. The increase in hunger lines is analogous to the well-known observation thatpoverty lines tend to rise as average incomes do (Ravallion et al., 1991; World Bank,
1990). It takes a larger income to barely survive as traditional sources of material support
are eroded in the process of modernization.

20

In the scenarios, hunger lines increase toward $3,670, the current inferred value for the United States, as mean
income approaches $21,880 (based on a linear fit to the data in Figure 13), and remain constant thereafter. Since
we do not have evidence that hunger lines stop increasing, this may be a conservative assumption.

42

Raskin, Gallopin, Gutman, Hammond and Swart

4,500

Hunger Line $/capita, PPP

4,000

Hong Kong

Mauritius

3,500
3,000
2,500
2,000
Hunger Line = 0.15 x GDP/Cap + $478/Cap

1,500

R2 = 0.59

1,000
500
0
0

5,000

10,00015,00020,00025,000Mean Income $ GDP/capita, PPP

Figure 13. Hunger Lines vs. Mean Income
Sources: Current hunger levels from FAO (1997a); Incomes from WRI (1996b). Hong Kong and Mauritius
excluded from regression. See Heaps, et al. (1998) for details.

Hunger in the scenario is computed as a function of population, income
distribution and the hunger line value in each region. The results are reported in Sheet S2. There is some increase in the number of undernourished people over the course of the
scenario, from 900 million currently, to 920 million in 2025, and 950 million in 2050.21
The result suggests that a significant decrease in hunger, as called for by the sustainability
targets, cannot be expected if current patterns of growth and distribution persist into the
future.
Regional variation of the incidence of hunger in the scenario is significant (Sheet
S-2). Africa shows the sharpest decrease in the percent hungry from about one-third in1995 to one-fifth in 2050, but by far the largest increase in absolute numbers. In China+
and South and Southeast Asia, hunger decreases, while in other developing regions there
is some increase. In the transitional regions of the Former Soviet Union and Eastern
Europe, the figures gradually creep higher as relatively equal income distributions tend
toward industrial country patterns.
While the quantitative analysis has focused on hunger, similar factors govern theother social indicators in Conventional Worlds-Reference scenarios — unsafe water,
illiteracy and life expectancy. Economic growth will tend to improve the conditions of thepoor, while growing populations and greater inequity are counteracting effects.
In
21

By comparison, hunger declines between 1989 and 2010 in a recent scenario (Alexandratos, 1995), apparently
based on income growth and a more egalitarian distribution of food, such as in the Policy Reform scenario (Sec. 4).

Bending the Curve: Toward Global Sustainability

43

general, the patterns for these indicators will be similar to those for nutrition. For
example, the percentage of those who are illiterate or lack safe water will decline, but thesustainability goals of significant reductions in absolute number will not be achieved.

3.5 Conclusions
Measured against our sustainability criteria, the Conventional Worlds-Reference scenario
would be a risky bequest to our 21st century descendants. The increasing pressure on
environmental systems — the combined effects of growth in the number of people, thescale of the economy and the throughput of natural resources — is environmentallyunsustainable. While there is great scientific uncertainty on how ecological systems would
respond to such increasing pressure and where thresholds of sudden change might lie, itdoes seem clear that the scenario would flirt with major ecosystem state changes andunwelcome surprises. Environmental feedbacks and impacts on human systems could
undermine a fundamental premise of the scenario: perpetual economic growth on a global
scale.
The scenario also fails to address the social goals for sustainability. Absolute
poverty persists, as nearly one billion people remain hungry in the middle of the next
century. The rapid average income growth assumed for all regions, which tends to reducepoverty, is negated by population expansion and the continued, even deepening, pattern oflarge income disparities. This contradicts the sustainability goal of substantial poverty
reduction. Beyond failing the ethical imperative of sharply reducing human deprivation,social conditions would be maintained that link human desperation and environmental
stress.
The persistence of economic polarization could compromise social cohesion andmake the spread of liberal democratic institutions more difficult and their maintenancemore fragile. Domestic and international tensions would be magnified by the resource andenvironmental pressures: conflict over water, regional concentration of petroleum
supplies, scarcity of land, climate change impacts on land and water resources, biodiversityloss.
In addition to greater disparities within many countries and regions, the absolutedisparity between rich and poor countries increases, though income grows fastest inpoorer regions. The desire to migrate to rich areas would grow stronger as would theresistance to such migration. Interregional inequity also could aggravate geopoliticaltensions. The fundamentalist backlash to the process of global cultural homogenization,
spurred in the scenario by advancing markets and the information revolution, would be
reinforced.
These social frictions, in the context of progressive environmental degradation,
could abrogate the business-as-usual continuity assumptions of the scenario. If allowed tofester, a xenophobic and isolationist Fortress World mentality could flourish in privileged
areas — and the United Nations may have a weakened capacity to mediate such tensions
in the market-driven world of the scenario. The danger would grow that the path ofhistory would branch toward some form of Barbarization scenario.

44Raskin, Gallopin, Gutman, Hammond and Swart

These risks are not inevitable. The tensions inherent in a Reference scenario canbe relaxed if development becomes more sustainable. While a Great Transition in social
arrangements and values may ultimately emerge, the transition to sustainability can besubstantially advanced within a Conventional Worlds paradigm. We turn now to aconsideration of the scope for such Policy Reform scenarios.

Bending the Curve: Toward Global Sustainability

45

4. STRATEGIES FOR A TRANSITION
Can a successful transition to sustainability be achieved within the confines ofConventional Worlds development assumptions? The policy-complacent Reference
scenario presents a picture of widening international prosperity in the next century. But it
is also a picture with disquieting elements — increasing environmental risk, resource
scarcity, tenacious poverty, and social stress. These threats could well negate thecontinuity assumption that underlies Conventional Worlds futures — steady economic
growth, gradual globalization, and cultural convergence. In other words, Reference-likescenarios may be both unsustainable and unrealistic. We ask next what types of strategies
could bend the curve of future development toward sustainability goals.

4.1 Policy Reform Scenarios
Policy Reform scenarios maintain the essential assumptions of the Conventional World
paradigm. The elements are by now familiar — the steady march of economic
globalization, the gradual convergence of all regions toward the evolving model ofdevelopment in industrial regions, and progressive homogenization of global culturearound the values of materialism and individualism. But there is a critical difference
between the scenarios. In contrast to the Reference scenario, Policy Reform scenarios
assume the emergence of a popular consensus and strong political will for taking action toensure a successful transition to a sustainable future. In this context, an integrated set of
initiatives are crafted and implemented including economic reform, regulatory instruments,social programs, and technology development.
In constructing the Reference scenario, we began with existing global conditions
and drivers of change. We then examined how the future might unfold over time. A
different method is required for formulating Policy Reform scenarios. Rather than aforecast into the future, a normative scenario like the Policy Reform scenario isconstructed as a backcast from the future (Robinson, 1990). We begin with a vision of adesired future state, defined by the sustainability goals, and seek to identify plausible
development pathways for getting there. Whereas business-as-usual scenarios pose thequestion of the forecaster — “where are we going?” — normative scenarios add thequestions of the traveler — “where do we want to go? How do we get there?”
Policy Reform scenarios elucidate the requirements for simultaneously achievingsocial and environmental goals of sustainability. The illustrative scenarios developed inthis study are based on the provisional sustainability goals described in Section 2. In someways these two sets of objectives are at cross-purposes — the economic growth requiredfor poverty reduction and greater equity tends to increase environmental pressure. In
other ways they are compatible, since more countries would have the economic
wherewithal for greater attention to long-range resource and environmental preservation.
We begin with the conditions for meeting the social goals, specifically the targets
for the reduction of human deprivation. The demographic, social equity and economic
development assumptions for meeting the social goals in Policy Reform scenarios become
the drivers of resource use and environmental impact in the scenario. Environmental

46

Raskin, Gallopin, Gutman, Hammond and Swartsustainability goals are addressed in the scenarios through strategies at the sectoral level— energy, food, land, water, waste. These are discussed in subsequent subsections.

4.2 Meeting the Social Goals
The absolute number of those in deprivation in the various regions of the world
will be determined by population levels and the entitlement of the poor to the means to
obtain food and other basic services (Sen, 1981). In Policy Reform scenarios, poverty
reduction and social goals are achieved through increasing the incomes of the poor. In
principle, this could be achieved both through structural changes that provide greater
access to income-generating activities and through welfare transfers, such as direct foodaid. Targeted assistance programs for meeting basic needs must have high priority, as
they address urgent and immediate needs, and can contribute to a self-sustaining processof raising the incomes of the poor (UNDP, 1997). However, a sustainable and resilient
response to the challenge of poverty reduction must ultimately be reflected structurally inaccess to decent and secure livelihoods.
Population growth is assumed to be lower in Policy Reform scenarios than the
Reference scenario for two reasons. First, the improved condition of the lives of the very
poor are assumed to be associated with declines in fertility rates as the cycle of poverty isbroken, access to education increases, and women become more empowered. Second,
more active family planning efforts in the policy scenario are assumed to reduce thenumber of unwanted pregnancies.
The critical elements in achieving the poverty reduction targets in the Policy
Reform scenarios are two types of equity increases. First, greater equity is assumed
between regions, aided by strategies that lead to more rapid economic growth indeveloping and transitional regions, and faster convergence toward OECD levels ofdevelopment. Second, greater equity within regions and countries is incorporated, as“growth with equity” becomes the prevailing philosophy in national development
strategies. Human development indicators become as important as the aggregate growth
in gauging national economic performance (UNDP, 1996).
These considerations inform the quantitative assumptions of the illustrative Policy
Reform scenario. Non-OECD population in 2025 is taken to be 98% of the UN mid-range
projection, and in 2050 to be 95% of the UN value (see Sheet D-1). This is a conservative
but reasonable assumption given the great uncertainty on the drivers of population growth(Bongaarts, 1997). The lower population levels help modestly in meeting the scenario
goals of reducing poverty and environmental stress. In all regions the tendency toward
increasing urbanization persists, as shown in Sheet D-2.
The economic and equity assumptions of the scenario are governed by three key
variables: world economy, international equity and national equity. The world economy,
expressed in terms of global GDP, is a measure of aggregate output, while theinternational equity variable characterizes the level of interregional equity, the manner inwhich the world economic pie is apportioned between poor and rich nations. The measureof international equity is the ratio of average income per capita in non-OECD regions toOECD regions. The current value of this ratio is about 0.15, while perfect interregional
equity corresponds to a value of 1.0.

Bending the Curve: Toward Global Sustainability

47

Future values of these two factors — the scale of the world economy and therelative incomes between rich and poor countries — determine the average incomes ineach country over time. To go beyond average income in order to describe the level ofpoverty in a scenario, we must also specify the income distribution within a given society.
The national equity variable is defined here as the ratio of the incomes of the lowestearning 20% of a population to the highest-earning 20% (alternative ways of representing
income distributions were discussed in Section 3.3). Perfect equity within a given society
would correspond to a value of 1.0. Actual values range widely across countries, e.g.,
0.14 in Denmark, 0.08 in the United States, and 0.04 in Brazil. Current average regional
values are reported in Sheet S-1 along with values for the illustrative scenarios. It is also
convenient to introduce a single global variable describing the average pattern of national
equity in a given scenario (see Sheet S-1).22
These variables — world economy, international equity and national equity —define a three-dimensional space (Figure 14). For a given year, a scenario appears as apoint in the space. Scenarios move through the space as the values of the variables changeover time. All trajectories depart from a common point, given by current values of theworld economy, international equity and national equity (1995 is the base year in thisstudy). In the course of time, each scenario defines a trajectory.
Reference scenario trajectories are shown in the figure as a family of scenarios
consistent with the underlying narrative and reflecting an uncertainty range across thevariables. The spheres suggest ranges of uncertainty in the variables. The central
Reference scenario described in Section 3 traces a path in which the world economy
quadruples by 2050, international equity improves gradually, and national equity
decreases.
Policy Reform scenarios also define a family of trajectories in the economic spaceof Figure 14, all of which must satisfy the sustainability goals. A specific goal is therequirement that the number of people who remain hungry in 2025 is one half and in 2050
is one-fourth current levels. In principle, there are multiple possibilities for lifting theincomes of sufficient numbers of the very poor above the “hunger line.”23 At one extreme,
if national equity continues to decrease, extraordinarily high global economic growth isrequired. At the other extreme, if the world economy grows at the same general levels asin the Reference scenario, then a much more equitable world would be necessary in order
to meet the social goals.

22

The global average value of national equity (X) is computed as the population-weighted average of the national
equity in each country (Xc). Thus, X t =∑ ( P ⋅ X ) P ,where P is global population and the indices c and t
c

c ,t

c ,t

t

t

signify country and year, respectively.
23

The hunger line and the approach for linking incomes to estimates of hunger are discussed in Section 3.3.

48

Raskin, Gallopin, Gutman, Hammond and Swart

0.16

1995

Policy Reform
0.14

0.16

2025

2050

0.14

Reference

0.10

0.08

2050

National

0.12

2025
0.10

Equity

0.12

0.08

0.06

omy
con
)
ld E
Wor 9 9 5 = 1
(1

1

0.06

2

0.10
0.15
3

0.20

ity
Equ
l
a
tion
rna
Inte
0.25

4

0.30
0.35

Figure 14. Scenario Trajectories
Note: International Equity = average income in non-OECD/OECD
National Equity = income of poorest 20%/richest 20%

The sphere of uncertainty for the Policy Reform scenario in Figure 14 suggests
ranges of economic scale and distribution variables that satisfy the social targets. In
practice, the set of scenarios of interest is limited to values of the economic growth andequity levels that are both compatible with the scenario narrative and lie within plausible
ranges. For example, since economic growth and global convergence are fundamental
premises of the Policy Reform story, the world economy and international equity variables
must increase substantially. National equity would also be expected to increase in a
scenario where poverty eradication became a policy priority.
At the same time, reasonable upper limits on GDP growth rates over the halfcentury time horizon of the scenario can be gleaned from an examination of historical data.
For example, the growth of the United States economy was around 3% annually over thelast 30 years. Some of the “Asian tiger” economies grew much faster over the same
period, by as much as 9% annually in some cases, but that era seems to be drawing to aclose in light of recent economic downturns and instability. Taking a longer perspective,
Thurow (1996) claims that “…over the past century, no country’s economic growth rate
has averaged better than 3.6 percent per year.”
The illustrative Policy Reform scenario assumes high but plausible economic
growth, in light of the robust global economy that is a key premise of the scenario. The
average annual GDP growth rate to 2050 is 2.7% for the world and 3.8% for developingBending the Curve: Toward Global Sustainability

49

regions (Sheet E-1). To meet the hunger targets under these conditions, national equity
needs to improve. This would be the case even if one were to posit very high average
economic growth to 2050. With the levels of inequality assumed in the Reference
scenario, GDPPPP in developing regions would have to increase at 6.5% per year to meetthe sustainability target. Such high growth is implausible and implies an immense
expansion in the scale of the world economy — by a factor of 15 — with correspondingly
greater strains on environmental systems.
In the illustrative Policy Reform scenario, the social targets are met through abalanced combination of effects — relatively strong regional economic growth, significant
but gradual motion toward international equity and maintaining national equity at close tocurrent levels. The scenario satisfies the hunger reduction target of 50% percent by 2025
and an additional 50% by 2050 (see Sheet S-2). As a result of differential income growth(Sheet E-3), international equity — the ratio of non-OECD to OECD incomes —increases from 0.15 in 1995 to 0.36 in 2050. Though the gap between rich and poor
nations is far from closed, the level of international equity is twice that of the Reference
scenario.
National equity in the Policy Reform scenario stays roughly constant at about 0.14
(Sheet S-2). While this is nearly twice the Reference scenario value in the year 2050, it iswell within the bounds of recent historical experience. For example, the United States had
comparable levels of national equity as recently as 1970 (Figure 10), while Europe ishigher today. The scenario calls for negating the trends toward high inequity, throughreforms in the policies governing distributional systems — policy reform, not extreme
egalitarianism.
The challenges are to simultaneously foster world economic growth, development
convergence and greater national equity, while remaining within environmental
sustainability goals. With the Policy Reform economic development assumptions set tomeet the social targets, we turn to the environmental aspects of the sustainability
transition.

4.3 Climate
In a Policy Reform scenario, strategies for the energy sector are strongly influenced byclimate change goals. The sustainability target for climate change is set as an upper limit
on global temperature change of 0.1° per decade (Section 2). To achieve this,atmospheric concentrations of carbon dioxide should stabilize at no more than 450 ppmv
by the year 2100, implying a cumulative carbon dioxide emission allowance of the order of
700 GtC between 1990 and 2100 (Section 3).
The issue of setting goals for carbon emissions has been the subject of considerable
international negotiation and contention. In these early years of the United Nations
Framework Conventions on Climate Change the focus is on near-term targets for carbon
reductions for the so-called Annex I countries.24 These more industrialized countries,
which have accounted for the bulk of carbon emissions historically, are committed to24

The Annex I parties to the FCCC correspond roughly to our three OECD regions and the two transitional regions ofEastern Europe and FSU.

50

Raskin, Gallopin, Gutman, Hammond and Swarttaking positive initiatives to reducing carbon emissions as an initial phase towards acomprehensive agreement. To attain climate stabilization, eventually all countries willneed to adopt greenhouse gas emission constraints. How should the burdens be shared?
What levels of allowable emissions are reasonable for each region and country?
An acceptable global agreement must include realistic reduction goals for theindustrialized countries while allowing some emission increases in developing countries as
economies converge in the course of the 21st century. Some form of equitable emission
rights must ultimately guide long-term policy. These principles are reflected in the Policy
Reform scenario. Several conditions determine regional emissions. First, abatementtargets are set for OECD and transitional regions through the year 2025. Second, allregions approach a common per capita emission allowance in the long term. Third,developing region emissions are restricted so that the cumulative global emissions from all
regions to the year 2100 are about 700 Gt.
Relative to 1990 levels, OECD regions are assumed to reduce annual emissions by
10% in 2010 and by 35% in 2025. The 2010 reduction target is somewhat greater thanagreed at the Kyoto climate meetings (UNFCCC, 1997). The goal for 2025, as we shalldiscuss below, is achievable through policies to promote additional energy efficiency,
renewable energy use and forest protection. The transitional regions, where emissions
dropped precipitously between 1990 and 1995 as their economies shrank, increase
emissions per capita between 1995 and 2010 as their economies recover, and then reduce
emissions from 2010 onwards.
The assumption of eventual convergence of all countries toward common percapita emissions (or “emission rights” in a tradable permit approach) addresses equity
concerns. The immense disparities in per capita emissions today (Sheet P-4) are the resultof many decades of divergent economic growth between rich and poor countries. They
cannot be eliminated rapidly without politically unacceptable disruption. However, thegoal of eventual equality is compatible with the assumptions in the Policy Reform world of
eventual equity and convergence across regions. In the scenario, it is assumed that annual
emissions converge to a common rate of 0.6 tC per capita in 2075, with equal per capita
emissions thereafter. This constrains emissions to about 3 GtC per year by 2100, given the
mid-range population projections in the scenario, which is required by the climate
stabilization goal. Finally, developing country emissions increase substantially over the
next decades, constrained by the global cap on cumulative emissions of 700 GtC and theconvergence target. The emission pattern for each of the three macro-regions, expressed
as emissions per capita, is shown in Figure 15.

Bending the Curve: Toward Global Sustainability

51

3.5
3.0

OECD

tC/year

2.5
Transitional
2.0
1.5
1.0

World
Developing

0.5
0.0
1990

2010

2030

2050

2070

2090

Figure 15. Energy-Related CO2 Emissions per Capita

In the developing regions, per capita emissions start from a much lower level thanin the OECD or transitional ones. They grow steadily until 2025, without ever exceeding
the industrial or transitional rates, then drop gradually to reach the 2075 convergencetarget. On a global basis, emissions per capita remain almost constant between 1990 and
2025, and decrease from 2025 to 2100. Combining emissions per capita with the
population projections we obtain total annual emissions in each macro-region, which areplotted in Figure 16. The total integrated emissions from fossil fuel combustion of about
700 GtC — the area under the curve in the figure — achieve the sustainability target.
Applying the same approach, emission goals can be assigned at the regional andcountry level (Sheet P-4). The OECD and transitional regions follow the general patterns
outlined above, while emissions in the developing regions follow various paths, dependingon their base year levels and their differing rates of economic growth. Achieving thesecarbon emission constraints requires a significant improvement in the way energy is usedand produced, a topic to which we now turn.

52

Raskin, Gallopin, Gutman, Hammond and Swart

8

6
Developing
4

2

Emissions(GtC/year)

10

OECD

2

Transitional
0
1990

2010

2030

2050

2070

2090

Figure 16. Annual CO2 Emissions

4.4 Energy
If there is to be a passage to an environmentally sustainable world over the next fifty years,
an energy transition will be at its foundation. The era of industrial development was basedon the emergence of modern forms of energy — coal, oil, natural gas and electricity —that were abundant, inexpensive and increasingly flexible. But energy has been a scourge
as well as an engine for industrial society, implicated deeply in many of its environmental
depredations — air and water pollution, acid rain, climate change, oil spills, toxic
emissions and many others.
The lesson of the Reference scenario is that gradual energy efficiency improvement
and modest renewable energy growth is insufficient to meet sustainability goals (Section
3). Aggressive action will be needed on both the demand and supply sides of the energy
equation. First, the intensity of energy use (energy requirements per unit of activity) willneed to be significantly moderated through the adoption of highly efficient energy-use
practices. Second, energy supplies must come increasingly from natural gas, as atransition fuel, and ultimately from solar, wind, biofuel and other renewables sources.
Assuming appropriate levels of regulation, research, and economic incentives,technologically and economically feasible pathways are available for each region that meetthe stringent constraints imposed by climate stabilization and other environmental goals.
Energy Intensity
The Policy Reform scenario illustrates how a sustainable energy transition might
be realized (Figure 17). Global energy requirements increase from 384 EJ in 1995 to 599
EJ in 2050, a 56% increase from present consumption, but 35% lower than the 929 EJ in
2050 in the Reference scenario (Sheet En-1). Energy use declines in the OECD by about
40% in 2050 relative to 1995 levels, compared to an increase of about 46% in the
Reference scenario. In the transitional regions, energy requirements remain stable to 2025
because improvements in energy efficiency are negated by a strong economic recovery.

Bending the Curve: Toward Global Sustainability

53

Developing region energy requirements increase by a factor of 3.1 between 1995 and
2050, less than in the Reference scenario, despite more rapid economic growth (Sheet E1).
World

OECD
300

1,000

Renewables
Hydropower
UraniumNatural Gas
Oil
Coal

800
200
EJ

EJ

600
400

100

200
0

0
1995 2025 2050
Reference

1995 2025 2050

2025 2050

Reference

Policy Reform

Transitional regions

2025 2050
Policy Reform

Developing regions

80

600
500

60
40

EJ

EJ

400
300
200
20
100
0

0
1995 2025 2050
Reference2025 2050
Policy Reform

1995 2025 2050
Reference2025 2050
Policy Reform

Figure 17. Primary Energy Requirements
Renewables include traditional and modern biofuels, as well as other renewable energy forms such as solar, wind, and geothermalenergy.

Energy intensity changes for the Policy Reform and Reference scenarios are shownin Figure 18. In the Policy Reform scenario, the energy required per unit of economic
activity decreases in OECD regions by 70% between 1995 and 2050. In developing
regions, the decrease is 60%. In transitional regions, where energy use is currently very
inefficient, energy intensities decrease by 78% between 1995 and 2050. The patterns inthe scenario are developed by first setting goals for OECD regions, based on technologicaland economic feasibility, and allowing gradual convergence toward these standards inother regions as income increases. In the scenario, some degree of technological“leapfrogging” is assumed as developing regions approach best future practices for energy

54Raskin, Gallopin, Gutman, Hammond and Swartutilization. The trends in energy intensity for OECD regions are shown at the sectorallevel in Figure 19 (Heaps et al., 1998).
OECD
12

12

10

10

MJ/PPP$ GDP

MJ/PPP$ GDP

World
14

8
6
4

8
6
4

2

2

0

0
1995

2025

Reference
Policy Reform

2050

1995

35

12

30

10

25
20
15
10

8
6
4

5

2

0

0
1995

2025

2050

2050

Developing regions

MJ/PPP$ GDP

MJ/PPP$ GDP

Transitional regions

2025

1995

2025

2050

Figure 18. Energy Intensities in the Scenarios

The Policy Reform scenario incorporates a wide variety of measures for achieving
energy intensity improvements. In the residential and service sectors, these include
improved space heating and cooling systems, more efficient appliances and lighting, better
glazing and building insulation, and greater use of heat pumps and passive solar heating
and cooling. In the industrial sector, there is greater use of recycled material feedstocks,
efficient motors, and combined heat and power technologies. In the transport sector,
vehicle efficiency improves sharply, e.g., in North America the current average mileage for
automobiles of 19 miles per gallon (mpg) reaches 32 mpg in 2025 and 51 mpg by 2050.
These improvements are well within the bounds of what is considered to be technicallyand economically feasible over the period to 2025. For example, efficiencies in newautomobiles could reach 75 mpg by that time (Energy Innovations, 1997). In the electric
power sector, a new generation of technologies, such as combined cycle thermal plants

Bending the Curve: Toward Global Sustainability

55

and integrated coal and biomass gasification provide substantial efficiency increases in themedium term. In the longer term, fuel cell-based technologies and greater use of
combined heat and power will be required to meet the sector efficiency goals of the
scenario.
Household Energy Intensities

8

Industrial Energy Intensities

6

GJ/capita

MJ/$PPP value added

27

4

21
18

2

15

1995

2025

2050

Passenger Transport Energy Intensities

GJ/pass-km

24

1995

70%

2.0

60%

1.5

50%

1.0

40%

1995

2050

Thermal Electric Generation Efficiencies

2.5

0.5

2025

30%
2025

2050

1995

Reference

Policy Reform

2025

2050

Figure 19. OECD Energy Intensity Improvements by Sector in the Scenarios

Fuel Switching
The second prong of a sustainable energy strategy is fuel switching to a greater
reliance on renewable energy sources, with natural gas as a near-term bridge fuel. The
composition of energy supplies shifts fundamentally in the Policy Reform scenario driven
by carbon emission targets (Figure 17). Similar patterns apply at the regional level (Sheet
En-2).
The combined share of the most carbon-intensive fuels, coal and oil, decreases
from 62% in 1995 to 37% in 2050, while the share of natural gas increases from 19% in1995 to 36% in 2050. This can be compared to the Reference scenario in which the shareof coal and oil remains almost constant (60% in 2050). Severe pressure on fossil fuel56

Raskin, Gallopin, Gutman, Hammond and Swart

resource availability (Section 3.3.2) is postponed but not entirely alleviated (Sheet En-5).
In addition, the scenario assumes the phase-out of nuclear generation for reasons noted in
Section 3.2. If the nuclear option were included, carbon emission and other environmental
targets could be met with corresponding decreases in the requirements for renewables andefficiency improvement.
The mix of renewable energy forms varies from region to region according tonatural resource endowments — hydro potential, insolation, availability of land, and thepresence of suitable water and soil conditions for modern biomass plantations. Renewable
options include biofuels as a feedstock for the industrial, transport and electricity
generation sectors, solar energy for electric generation and for direct applications inhouseholds and industries, and wind and geothermal energy for electric power generation.
Hydropower development is limited to the same levels foreseen in the Reference scenario,
due to the need to avoid the environmental impacts often associated with many largehydro schemes. Solar and wind development for electricity generation is limited by theirintermittent nature.
Levers of Change
The efficiency and fuel-switching initiatives in the scenario require neither heroic
technological assumptions nor economic disruption. Indeed, the promotion of energy
efficiency and renewables is not only compatible with economic development and job
stimulation, it may in fact further these goals (Energy Innovations, 1997). The primaryconstraints to achieving the energy goals are institutional and political.
Numerous policy options are available. Fiscal mechanisms can be used tointernalize environmental costs into energy prices, e.g., through the use of carbon taxes orcarbon-trading systems. Carbon taxes can be coupled to reductions in other taxes as intax shift policies already adopted in some European countries. Fossil fuel subsidies can beeliminated. Progressively more stringent energy efficiency standards can be set. New
financing initiatives and economic incentives can help spur investment in energy-efficientand renewable technologies. Increased research, development and demonstration efforts
can offer new technological opportunities. Market barriers to efficiency and renewables
investment can be overcome through better information, capacity building and institutionalframeworks. Globally, initiatives to transfer technology and know-how can help makeenergy efficiency and renewables a foundation for the growing infrastructure ofdeveloping economies.

4.5 Food and Land
The Reference scenario offers a mixed picture for food and agriculture. On the one hand,production keeps pace with steadily increasing requirements for food and otheragricultural commodities. On the other hand, the doubling of agricultural output by 2050
contributes to substantially increased pressures on land and water resources. Also,
increased chemical inputs to farming systems add to terrestrial and water pollution. The
need for new agricultural land is amplified by the continuing degradation of existing
cropland. Along with expanding settlement areas, this leads to the loss of forest areas andother ecosystems, at rates comparable to those in the recent past.

Bending the Curve: Toward Global Sustainability

57

The difficulties of meeting global food requirements in environmentally sustainableways are even greater in Policy Reform scenarios. Meeting the social goals of the
scenarios implies rapid economic development, more equitable income distributions andgreater food demands. While dietary patterns remain invariant in rich countries, diets
improve and animal products grow as a share of dietary intake elsewhere (Sheet F-1).
Global food requirements for cereals increase 60%, from 990 million tonnes to 1,560
million tonnes over the scenario, while the demand for meat rises almost 2.5 times, from
260 million tonnes to 630 million tonnes.
The challenge of simultaneously meeting all the sustainability criteria introduced in
Section 2 is formidable. Increased agricultural requirements must be met under multiple
constraints: forest and habitat protection reduces the scope for the expansion ofagricultural land; decreasing the level of stress on water resources in water scarce areas
limits the use of irrigated water; and reducing land degradation and chemical inputs toagriculture requires more sustainable farming practices, while maintaining yield increases.
In the Policy Reform scenario, the often conflicting goals of providing space forhuman settlements, protecting ecosystems, and feeding human populations can bereconciled only through a combination of measures. These include:• Sustainable farming practices. A transition to agricultural sustainability will requirea “doubly green” revolution, in which agricultural productivity continues to improve
but with practices that preserve the environmental foundation for the long term
(Conway, 1997). The focus shifts from the genetic manipulation of crops to increase
yields toward enhancing the productivity of complex farming systems (Swaminathan,1997). In the scenario, a campaign for sustainable agriculture is launched resulting ina gradual shift toward ecologically sound practices, rather than the replication of highinput farming. The challenge is to maintain yield improvements at something like
Reference scenario levels. As part of the pollution-reduction goals of the Policy
Reform scenario, fertilizer and pesticide use per hectare declines. To maintain yields,
the nutrient requirements of plants must be met, and pests kept in check, in other ways
(Conway, 1997). Nutrient recycling partly substitutes for fertilizer, for example, byusing livestock manure in combined crop-livestock systems and through large-scale
composting. Nitrogen requirements are met in part through the use of nitrogen-fixing
plants that can be grown in rotation with or in combination with other crops. Pesticide
requirements are reduced through the development of pest-resistant strains of plants
and the widespread use of integrated pest management. The poverty alleviation goalsof the scenario support these trends, as increasing income allows farmers to diversify
their production (Scherr and Yadav, 1996). Additional actions needed include thedevelopment and application of biotechnology and other research (e.g., disease
resistant varieties), education and training of farmers, land reform, infrastructuredevelopment and reform of economic policies. Programs for sustainable agriculture
must be carried out in cooperation with farmers and targeted to local needs (Leach,1995).
• Fisheries and Aquaculture. In the Policy Reform scenario, fish consumption
increases, from about 100 million tonnes in 1995 to about 160 million tonnes in 2050,
only slightly less than the 170 million tonnes required in the Reference scenario (Sheet

58

•

•

Raskin, Gallopin, Gutman, Hammond and Swart

F-3). Better management of capture fisheries extends the current production ofaround 85 million tonnes per year to a sustained annual production of 100 million
tonnes (FAO, 1997c). About 10 million tonnes of the total increase comes from
replenished stocks, as access to overexploited fisheries is restricted through thecreation of limited fishing rights and other initiatives. A further 5 million tonnes isgained through a reduction of losses and discarded by-catch. These changes arebrought about by better technology, legal limits on discards, and the expansion ofmarkets for the products of by-catch. About 60 million tonnes of global requirements
cannot be met on a sustained basis from capture fisheries. Aquaculture expands tomeet this additional demand, with production roughly tripling from the 20 million
tonnes from this source in the base year (FAO, 1997c). In the past, aquaculture has
led to pollution and pressures on freshwater resources (Brown, et al, 1998). These are
reduced in the scenario by the introduction of water-conserving technologies,
encouraged by water-conservation and pollution-prevention policies.
Pasture and rangeland. Changes in grazing land for livestock production are subject
to competing effects. On the one hand, the robust Policy Reform economic growth
assumptions drive the demand for meat products higher. On the other hand, thescenario assumes a greater reliance on feedlots in livestock production (Sheet F-2).
Greater reliance on feedlot production is both a consequence of rapid economic
growth and a matter of policy. While agriculture production must expand to meetincreased livestock feed demand, reducing the requirements for grazing land has thenet effect of reducing pressure on forests and other ecosystems. In addition, some
improvement in grazing land productivity can also be expected due to the adoption ofmodern practices and improvements in herd quality. At the same time, both grazing
and feedlot production practices must become more sustainable in order to reduce
environmental pollution. For example, large feedlot facilities produce vast quantities
of concentrated manure, contributing to nitrate pollution of ground water andammonia emissions, a precursor of acid rain. Part of the answer is more integrated
crop-livestock systems in which manure is recycled to crops as fertilizer (Durning andBrough, 1991; Bender, 1994). The transition to sustainable livestock practices can be
reinforced by providing information through extension services, and by enforcing antipollution laws. In arid lands, where the availability of forage can vary greatly fromyear to year due to climate fluctuations, policies to provide timely access to markets
and land can allow pastoralists to cope without overtaxing biomass resources(Conway, 1997).
Cropland. Driven by the combination of food and feed requirements, global croplandarea expands by about 20% between 1995 and 2050, a larger increase than the 11% of
the Reference scenario. However, because of land and water constraints in many
regions, the largest increases occur in regions with the least land and water constraints(Sheet F-6). This implies more extensive trade in food commodities, as discussed
below. In North America, where cropland grows by over 40%, some of the increase ismet by returning to production land held in the U.S. Conservation Reserve Program.
Globally, a greater share of the cropland is on rainfed land than in the Reference
scenario. Expansion of irrigated land is discouraged by increases in water prices, as
countries try to limit the incidence of water stress, the topic of the next section.

Bending the Curve: Toward Global Sustainability

•

•

•

•

59

Land degradation. Consistent with the sustainability goals (Section 2), the rate ofland degradation slows between 1995 and 2025, and then reverses between 2025 and2050. Loss of cropland due to severe degradation drops to 1.5 million hectares per
year over the first half of the scenario, half the rate assumed in the Reference scenario.
From 2025 to 2050 cropland is restored, leading to the return of degraded land to
cropland, forests and other land types. Depending on the nature of the land and its
use, degradation is reduced through different means. Improving drainage and delivery
systems for irrigation water can restore irrigated land subject to waterlogging andsalinization, and conserve water resources at the same time. Nutrient loss fromshifting cultivation can be reduced by lengthening fallow periods. Loss of landthrough water erosion can be reduced by building terraces and through conservation
tillage. When the terraces are reinforced by planting nitrogen-fixing trees, they can
add to the fertility of the soil, as well as retaining water and reducing erosion(Conway, 1997).
Built environment. Under business-as-usual conditions, the expansion of settlement
areas is likely to claim a significant amount of arable land, forest area and drylands, as
illustrated in the Reference scenario (Sheet P-6). The expansion of the built
environment is curtailed in the Policy Reform scenario, as concerns for protecting
productive cropland, forests and other ecosystems lead to urban planning policies thatfavor more compact settlement patterns. This would be supported by a higher
valorization of arable lands driven by increasing domestic demands and, in someregions, profitable opportunities for increased trade. All regions gradually movetoward Western European patterns (Sheet P-7).
Forest land. The preservation of forests and other valued habitats and ecosystems is a
key sustainability goal. Specifically, the rate of forest loss gradually decreases in the
scenario to zero by 2025 and forest areas increase thereafter. These goals contrast
with both historic and Reference scenario patterns in which deforestation proceeds at
about 10 to 15 million hectares per year. These trends are reversed by forest
protection policies and land-use strategies that support more compact settlements, thecontraction of grazing lands and land restoration. In the scenario, the amount of forest
land set aside as protected areas increases. Also, opportunities are developed forencouraging the sustainable use of forest products among the poor, e.g., by granting
secure land rights (Scherr and Yadav, 1996). Finally, the sustainable management offorests by the timber trades becomes a priority everywhere, including the preservationof critical levels of old forests and other ecosystems for the support of biodiversity.
As a result, loss of forest is reduced from 700 million hectares in the Reference
scenario to below 250 million hectares between 1995 and 2025. Between 2025 and
2050, there is net reforestation.
Agricultural Trade. Many countries and regions butt against the limits of theirresource constraints in the Policy Reform scenario. Indeed, we find that meeting
expanding food requirements while staying within environmental constraints will
require greater reliance on imports in a number of countries (e.g., Africa and the
Middle East). Increased reliance on imports is made possible by the rapid economic
development assumed in the Policy Reform scenario, which supports enhanced
participation of developing regions in international commerce (Sheet F-4). This

60

Raskin, Gallopin, Gutman, Hammond and Swartrequires considerable expansion of production from exporting regions, such as North
America, Western Europe and Latin America, and from the transitional regions of theformer Soviet Union and Eastern Europe (RIVM/UNEP, 1997). While this would
counter trends over the last twenty years of withdrawing lands from production inindustrialized regions, the scenario assumes heightened concern in the OECD regions
for maintaining forests and other ecosystems in developing regions. Furthermore,
growing demand for agricultural commodities from increasingly wealthy developing
regions makes expanded production more profitable.
However, to maintainproduction so that the food requirements of developing regions are met while
preserving ecosystems worldwide will likely require far-sighted policy measures that
do not rely on markets alone (Leach, 1995).
Land-use patterns in the Policy Reform scenario that result from these
considerations are reported in Sheets P-6 and P-7 and summarized in Figure 20. The
rapid expansion of the built environment and grazing land areas in developing regions that
occurs in the Reference scenario is slowed or reversed. In OECD and transitional regions,the slowly changing land-use distributions of the Reference scenario are replaced by amore dynamic picture, as cropland area grows to supply the increasing import needs ofcountries facing land and water constraints.

Bending the Curve: Toward Global SustainabilityOECD

14,0003,500

12,000

3,000

Past./Range

10,000

2,500

Other

2,000

Forest1,500

Cropland

1,000

Built
Environment

million hectares

millions hectares

World

8,000
6,000
4,000
2,000

Protected

500

0

0

1995

2025 2050

2025 2050

1995 2025 2050

Reference

Policy Reform

Reference

Transitional Regions

2025 2050
Policy Reform

Developing Regions

2,500

8,000

2,000
millions hectares

millions hectares

61

1,500
1,000

6,000

4,000

2,000

500
0

0
1995

2025

2050

Reference

2025

2050

1995 2025 2050

2025 2050

Policy Reform

Reference

Policy Reform

Figure 20. Land-use in the Scenarios

The task of feeding a world with almost twice as many people as today, while
maintaining the productivity of cropland and forests, and avoiding unmanageable
pollution, presents numerous challenges. There is no simple recipe for achieving
sustainability in land-use and agricultural production. The scenario presents a picture of
how this might be accomplished. It also underscores the multidimensional character of the
problem, the variety of the types of initiatives needed and the immense policy challenge.
Concerted government action will be needed to build the required capacity for researchand extension services, provide well-functioning markets and adequate infrastructure,correct perverse subsidies, and implement incentives for a shift toward more ecologicalagriculture, forestry, and land-use practices. The adequacy of water resources will play a
critical role in achieving these goals.

4.6 Freshwater
Approximately one-third of the world’s population lives in areas experiencing some formof water stress. In the Reference scenario, the figure rises to over 50% in 2050, or close
to 5 billion people. The heightened competition for water increasingly threatens valuableecosystems and habitats that depend on an adequate supply of clean water, and causes

62

Raskin, Gallopin, Gutman, Hammond and Swarttension between users sharing common water resources.
sustainability criteria.

These trends violate

Abating freshwater degradation and scarcity is an exceedingly daunting task. The
practical difficulty is reflected already in the sustainability goals articulated in Section 2.
They accept that increased water stress is unavoidable, though at levels well below thosein the Reference scenario. In the Policy Reform scenario, the transition to theenvironmentally sustainable use of water resources is in some ways at cross purposes withefforts to meet the social goals. The requirements for water services increase as a result ofefforts to deliver household water services to the poor and by the rapid expansion ofdeveloping country economies.
In the context of rising end-use requirements, freshwater withdrawal is moderated
in the scenario through several types of measures: efficiency improvement, resource
enhancement and agricultural trade increase. The scenario analysis is conducted at thenational level in order to more accurately match water demands and resources. Measures
are introduced in each country for satisfying the freshwater sustainability goals of Table 5.
Aggregate global water requirements in the Policy Reform scenario increase 10% between
1995 and 2025, and then decrease by less than 5% from 2025 to 2050. Regional patterns
are shown in Sheet P-1 and are compared to the Reference scenario. In the developing
regions as a whole, requirements change little between 2025 and 2050, after a 25%
increase between 1995 and 2025. In the water-stressed Middle East, water withdrawals
increase by about 15% from 1995 to 2025, substantially less than the 50% increase in the
Reference scenario, and between 2025 and 2050 withdrawals decline, to reach levels
slightly above those in the base year. Industrial intensity improvements in the former
Soviet Union, where current values are relatively high, lead to lower total requirements in
2050 than in 1995. In the OECD as a whole, withdrawals decrease throughout the
scenario, dropping by over 30% between 1995 and 2050.
The major features underlying these results include:•

Increasing drivers of water use. All else equal, growing economies, particularly indeveloping regions under Policy Reform assumptions, drive water demands beyond
environmentally sustainable limits in many countries and river basins. As discussed
below, end-use water requirements would have to be met far more efficiently and, tosome extent, with non-conventional water sources. In addition, in some cases water
demands can only be kept within sustainability goals by reducing requirements, e.g.,land under irrigation. In the Middle East, where water scarcity is particularly acutetoday, irrigated land areas decrease in the scenario, by about 10% relative to 1995
levels. The reduced agricultural production is made up through trade; in effect,
countries in this region import the water embodied in agricultural products.

•

Efficiency improvement. Overall improvements in aggregate water intensity (use perunit GDP) are summarized in Figure 21 for the macro-regions. Two factors contributeto the decrease in aggregate intensity. First, the composition of economies changes inthe scenario so that the water-intensive agriculture sector contributes a diminishingshare. This alone lowers water intensities in the scenarios. Second, water is used
more efficiently as illustrated by the sectoral water intensity trends illustrated in Figure
22 for the OECD region. We begin with irrigation intensities. Recall that water

Bending the Curve: Toward Global Sustainability

63

requirements increase to meet the water requirements of higher-yielding crops asreflected in the increasing Reference scenario intensities in Figure 22. The lower
intensities in the Policy Reform scenario are due to the implementation of a variety ofmethods to increase the efficiency of irrigation over conventional practices (Postel,
1992; Seckler, et al., 1998). For example, spray irrigation systems can be replaced bytrickle and drip irrigation systems; open canals can be covered; and subirrigation, in
which groundwater is raised to the level of roots, can be introduced in some areas.
Numerous opportunities are available in the domestic sector, as well, through higher
market penetration of water-efficient appliances and tighter plumbing codes. In many
developing regions, domestic water intensities increase as incomes rise, but more
slowly than in the Reference scenario. Industrial water intensities also decrease
towards best practice levels today, such as those in Israel, where aggressive waterpricing schedules and standards for water-conserving technologies have led to highly
efficient water use by industry (Lonergan and Brooks, 1994). Measures to achievethese targets include water recycling, using saline or brackish water for cooling, andchanging to less water-intensive industrial processes. Aggregate intensities alsochange in response to changing industrial mix, toward less water intensive subsectors.
•

Resource expansion. The scenario assumes greater investment in desalinization
facilities, particularly in coastal water-scarce areas, and increased capture of treatedwastewater for reuse in selected applications. Currently, in the Middle East and North
Africa some countries meet a substantial amount of their domestic and industrial waterrequirements through desalinization and wastewater treatment (FAO, 1996a). For
example, in Kuwait over half of water withdrawals are met with these nonconventional sources. For the region as a whole, desalinization and wastewater
recapture is not cost-effective for most countries, constituting less than 1% of total
supplies. In the scenario, water shortages stimulate increased investment in thesesources, and by 2050 the Middle East meets about 6% of its water requirements fromdesalinization and wastewater treatment. Individual countries satisfy between 10%
and over 50% of their requirements this way. In North Africa, countries that currently
supply some of their water requirements through water treatment plants expand theircapacity so that by 2050, 10% of their water withdrawals are supplied by desalinatedor treated wastewater.

64

Raskin, Gallopin, Gutman, Hammond and Swart

World

OECD

125

60

Reference
Policy Reform

m3 / $1000

m3 / $1000

100
75
50

40

20

25
0

0
1995

2025

2050

1995

Transitional

2025

2050

Developing
200

300
250
m3 / $1000

m3 / $1000

150
200
150
100

100
50

50
0

0
1995

2025

2050

1995

Figure 21. Water Intensities in the Scenarios
Cubic meters per $1000 of GDPPPP

2025

2050

Bending the Curve: Toward Global Sustainability

Domestic Intensities

12

150

11

130

m3 / capita

km3 / Mha

Agricultural Intensities

10

9
1995

2025

65

2050

110

90
1995

2025

2050

Industrial Intensities
100

Reference
Policy Reform

m3 / $1000

80
60
40
20
0
1995

2025

2050

Figure 22. OECD Water Intensity Improvements by Sector in the Scenarios

These factors combine to keep national freshwater withdrawal requirements within
the sustainability targets (Table 5). Aggregating to the regional level, trends in the useto-resource ratio in the scenario are reported in Sheet P-3. Globally, the population inwater stress rises to nearly 40% in 2025, and stays at that level from 2025 to 2050.25
Global totals for the number of people in water stress in the Reference and Policy Reform
scenarios are shown in Figure 23. In the Policy Reform scenario the incidence of severe
stress (national use-to-resource ratios greater than 0.4) remains almost constant between
2025 and 2050, in contrast to the Reference scenario, where it increases by about 30%
over the same period. The population in moderate stress is greater in the Policy Reform
scenario than in the Reference scenario, but this increase is from countries that are
severely stressed in the Reference scenario.

25

As with the Reference scenario, the fraction of national populations in water stress is assumed to rise from zero to100% as the use-to-resource ratio rises from 0.1 to 0.4.

66

Raskin, Gallopin, Gutman, Hammond and Swart

5

SevereStressbillions of people

4

Moderate
Stress

3
2
1
0
1995

2025
2050
Reference

2025
2050
Policy Reform

Figure 23. Population in Water Stress in the Scenarios

The Policy Reform scenario suggests that pressures on freshwater resources canbe substantially reduced. The sustainability goals, though rather weak, can be met inprinciple but would require vigorous policy initiatives. The most efficient new irrigation
technologies are expensive, as are desalinization plants, and their introduction will need to
be encouraged by water-pricing policies and efficiency standards. In many places today,
water use is subsidized, perversely favoring inefficient use (Postel, 1992). To reach thesustainability goals these subsidies must be removed or reduced, and water priced toreflect its full economic and environmental value. Policies directed at other sustainability
goals will also be useful; for example, water pollution abatement can induce benefits suchas increased water-use efficiency.
In the past, freshwater development was largely about water systems engineering,
infrastructure development and flood control. Water sustainability will require an
expanded perspective that considers the multi-faceted role that water plays in servicing
human and ecological systems. If water development remains fragmented and wasteful,the prospects for sustaining the environment diminish and the possibilities for conflict riseas economies grow. But if an integrated river basin planning framework takes hold, onethat can involve stakeholders in a process of collaboration in order to balance the manyclaims on freshwater, then the water sustainability era can begin. The goals of developing
a new paradigm for sustainable water use, and building the capacity for its implementation,command policy attention.

4.7 Materials and Waste
The resource use sustainability targets (Section 2.2) are partially addressed throughstrategies already discussed to reduce the intensity of fossil fuel extraction, to control soil
erosion, and so on. But much more would be required to manage the level of material

Bending the Curve: Toward Global Sustainability

67

inputs to industrial economies and the environmental impacts of waste loads.
Dematerialization at the required level requires efforts across several dimensions (Jackson,1993).
At the facility level, processes can become cleaner and far more efficient in theiruse of natural resources. At the commodity level, product lifetimes can be lengthened,
thereby reducing the discard rate and need for virgin materials. At the system level,“waste” streams can be reconceptualized as resource streams through the reuse of
products, remanufacturing of components and recycling of materials. Ultimately, detailed
consideration must be given to the system impacts of alternative processes and materials
through life-cycle analysis that considers both the direct and indirect impacts ofalternatives.
In addition, aggregate reduction in the intensity of resource use will be aided byshifts in the composition of the economy from resource-intensive to knowledge-intensive
sectors. In the end, reducing the throughput of materials to lie within tolerable
sustainability boundaries may require a moderation in consumerist lifestyles. However, thiswould carry us beyond the premises of Policy Reform scenarios.
Scanning across the various elements that comprise the Policy Reform scenario,
the complex and multi-dimensional character of a policy-driven sustainability transition
becomes apparent. The discussion of the food-water-land nexus of issues illustrates themany obstacles that will be faced in servicing growing economies, meeting human needs,
and passing on a healthy environment. Moreover, the tension between two assumptions inthe scenario will not be easily reconciled — the continuity of dominant values andinstitutions, on the one hand, and the greater equity for addressing poverty reduction,
climate protection, and other goals, on the other hand. At the very least, a comprehensive
action agenda will be needed to begin to bend the curve of development towardsustainability.

68

Raskin, Gallopin, Gutman, Hammond and SwartBending the Curve: Toward Global Sustainability

69

5. IMPLICATIONS FOR ACTION
The Conventional Worlds-Reference scenario allows us to gauge the risk of inaction. The
scenario fails to meet fundamental sustainability goals across a number of dimensions —basic human welfare, international equity, environmental quality, and resource
preservation. The case is compelling for immediate and strong initiatives to change
course. But history teaches that a need for action, in principle, does not mean thatappropriate action will be taken, in practice.
The Conventional Worlds-Policy Reform scenario gives a concrete illustration of
how a redirection towards sustainability could come to pass. It shows that simultaneously
meeting social, environmental and resource goals requires overcoming a daunting andinteracting set of constraints. Nevertheless, gradual changes in social, technological andresource-use patterns become cumulatively significant over the coming decades. The
curve of global development bends toward a more equitable and environmentally healthy
future. What then are the challenges to a transition to a Policy Reform scenario? What
policies are needed? Is policy reform enough?

5.1 Challenges
The quest for a sustainability transition within the Policy Reform framework poseschallenges that should not be underestimated. Recall that this scenario assumes essential
continuity with current institutions and trends. The values, lifestyles, governance systems,
and economic structures of Conventional Worlds may evolve slowly, but theirfundamental character endures. Change comes as a set of corrections and adjustments tomarket-driven development, rather than as a passage to a new mode of civilization, as
envisioned in Great Transition scenarios.
In the Policy Reform context, an effective campaign for a sustainability transition
will require the fulfillment of several conditions:•widespread awareness of the issues and the conviction that action is necessary;•adequate institutions, policies, and technologies; and,•sufficient political will to accept the costs of carrying out the required actions.

Growing scientific understanding of the risks of unsustainable development is anecessary ingredient. But science alone is insufficient to galvanize timely and appropriate
action: witness the many climate change skeptics despite the high level of international
scientific consensus on the threat of global warming. In the social realm, resistancepersists to strong measures to reduce inequity and eliminate poverty. Even among theinternational financial institutions charged with poverty alleviation, such as the World
Bank, there is continued reliance on “trickle down” economics. In developing countries,
the structural adjustment programs of the last decade, while correcting macroeconomic
failures, have not adequately addressed increasing income disparities.
Ultimately, the greatest challenge is the third item identified above: the willingness
to implement and accept the costs of necessary changes. Many stakeholders —governments, businesses, political parties, and other social groups — remain reluctant tomake sustainability a real priority for action. In the absence of that resolve, pressures that

70

Raskin, Gallopin, Gutman, Hammond and Swartreinforce unsustainable patterns prevail: economic subsidies often foster environmental
disruption, emphasis on short-term economic benefits discounts the future, policies
weaken support for the poor out of concern for global economic competitiveness, businesspractices pollute and deplete resources, and consumerism remains the dominant lifestyle.
The sustainability transition calls for placing higher values on interests thatheretofore have been neglected: the plight of the poor, the rights of future generations,and the integrity of ecological systems. As with any call for a major reordering of social
priorities, the transition to sustainability can expect resistance. Proposals for theempowerment of disenfranchised people, for more moderate per capita material
consumption of affluent groups, and for increased international commitments forsustainable development will be contested, particularly by those who benefit most from thecurrent state of affairs. The dialectic of political change — public pressure from below
and leadership from above — will need to overcome such resistance by building a new
vision and consensus for a politics of sustainability.

5.2 Agents of Change
Within a Conventional Worlds framework, the transition to sustainability entails both the
deployment of environmentally friendly technologies and the reform of institutions. The
Policy Reform scenario, summarized in Section 4, confirms that much of the technology
and practices necessary for a transition to sustainability are at hand. A vast repertoire oftechnical means is available for sustainable food production, cleaner energy, materials
recycling, efficient water use and pollution prevention. While continuing research anddevelopment will further enrich the technological possibilities, the immediate challenge isthe redirection of institutional forces.
Environmental degradation is not an inherent fact of our time. It results from a setof historically contingent choices for technology, production processes, and consumption
patterns. Similarly, poverty and extreme inequity are not inevitable, but rather are theoutcome of a specific period of world history. These distributional patterns are embedded
in a set of institutional mechanisms that are stubborn, but not immutable. For millennia,
human societies produced little surplus and functioned near the edge of survival. Withlimited social wealth, economic redistribution could not eradicate the poverty of the many.
The surge in productivity since the industrial revolution has changed the problem ofpoverty eradication from a technological to an institutional issue. The challenge is not somuch to increase output as it is to fairly distribute resources, know-how and entitlements.
The precondition for sustainability is forging the political and social will forchange. That resolve will need to then find expression through reshaping traditional
institutions and harnessing the potential of emerging ones. The former refers to the formal
processes of economies and governance, and the latter to the full gamut of social
arrangements that offer opportunity for discussion and action concerning social goals andmeans.
Regarding economic institutions, some advocates of laissez-faire see modern
market economies as something akin to natural phenomena. Yet economies are humanarrangements, which are not above society, but are part of it. Economic institutions haveundergone enormous changes through history including the abolition of slavery, the rise of

Bending the Curve: Toward Global Sustainability

71

the welfare state, the transformation of financial sectors, and globalization. In thediscussion of strategies for sustainability, economic institutions need to be understood, not
as a given, but as part of both the problem and the solution. Eventually, changes in social
values and technology could lead to fundamental economic transformation. But even in a
Policy Reform world, a wide array of economic instruments is readily available tomotivate environmental sustainability in the market place, as we shall review in thefollowing section.
Large corporations are increasingly powerful agents of change as the global sweepof their influence advances. On the one hand, they have the capacity to accelerate thetransition to sustainability. On the other hand, they are accountable ultimately to theirshareholders, not to an electorate, since the primary objective of business is profit, notsocial welfare. Nevertheless, there are preliminary signals that the private sector may bechanging in response to the challenges of sustainability and environmental responsibility,
as some of its leaders articulate a genuine concern for the state of the future.
It is naïve to blame government and international agencies for all of society’s flaws— or look to them as the panacea for the transition to sustainability. Enlightened
initiatives by governments and agencies, spurred by politically engaged constituencies, will
be necessary ingredients of major change. Governments remain the locus of public policy
and the primary bodies concerned with public welfare. Yet nation-states are in some ways
too big for the small problems, and too small for the big ones. The power of nation-stateshas been diminishing as globalization makes national borders more porous. Moreover,
governmental bodies are constrained by inertia, the lobbying pressure of powerfulstakeholders, and a short-term interpretation of voters’ aspirations — a naturalconsequence of electoral cycles that last just a few years. The momentum for overcoming
these constraints will need to come from outside, rising among the countless new
associations taking shape today.
Myriad new institutional actors have entered the stage in recent years. A chorus of
new social actors is appearing: grass roots movements, non-governmental organizations(NGOs), interest groups and emerging forms of social organization such as virtual
networks. The agendas are as diverse as the players. Some address broad themes such as
gender, the environment and the rights of indigenous peoples. Specific local mattersmotivate many others. The capacity of these groups to educate, articulate demands, andfoster change is growing. As never before, transnational businesses, international agencies
and governments must acknowledge and answer the challenge of these new institutions.
Meanwhile, traditional organizations, such as religious groups and charities are changing
their roles, and networks of scientists, citizens, artists, special interest groups, and manyothers proliferate.
As with any major technological breakthrough, the communications revolution
offers contrasting possibilities for society as a whole. It provides the means tocommunicate at a scale and speed that is unprecedented. The communication revolution
can serve to foster social mobilization for a more sustainable and just world. But it canalso lead to a media-dependent citizenry that overreacts to contradictory messages,
marketing slogans and media-manipulated fears.

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Raskin, Gallopin, Gutman, Hammond and Swart

The primary agents for a Policy Reform scenario are likely to be governments,
businesses and NGOs. The new institutions of civil society have a critical role to play inchampioning such a change of direction. Furthermore, for the fundamental valuetransformations envisioned in Great Transition scenarios to emerge, these groups will play
the critical role.

5.3 Science for Sustainability
Science has much to contribute to the sustainability transition, supporting discussion andaction with analysis, information and solutions. The last twenty years have witnessed an
accelerating translation of environmental concerns into scientific research programs.
Stratospheric ozone depletion, global warming, biodiversity loss, and ocean pollution are
only a few of the issues that have received focused research attention. We can be hopefulthat others will follow.
As society turns increasingly to science for answers to environmental dilemmas,
the scientific professions progressively have come to see environmental studies as
legitimate areas of research. Conventional disciplinary boundaries have been transcended
as the needs are acknowledged for interdisciplinary approaches and for scientificparticipation in the discussion of social choices. Indeed, we hope this study will be seen as
part of the initiative to build bridges between scientific discourse, social values and thepolicy agenda.
The challenge is considerable: to understand the dynamics and possibilities ofwhole socio-ecological systems with approaches that are scientifically rigorous yet
sensitive to the inherent uncertainty and the normative character of the problem. There is
growing recognition of the need for such a new scientific paradigm. The discussion ofscientific research priorities for a sustainability transition is continuing within the scientificcommunity (BSD, 1998), and need not be elaborated here.
What is worth stressing is that scenario analysis can play a key integrative role incoupling science to the public dialogue on the future. Scenarios provide a framework forsynthesizing diverse findings from natural and social sciences. Moreover, scenario analysis
guides research by identifying missing information and key areas of uncertainty. Scenarios
for the sustainability transition must be both comprehensive and integrated, and are neededat various spatial levels in order to “see” issues that only come into focus in the zoom
from the global, to the regional, to the local.
This implies practical action. One of the most urgent knowledge-needs is for
integration across policies, instruments, sectors and issues. The need for a systemic
approach was explicitly recognized in Agenda 21, but there has been little progress since.
Integrated sustainability studies should be conducted at all levels. They should becomprehensive, participatory and adaptive. Useful science for the transition must stressintegration, recognize uncertainty, appreciate irreducible normative aspects, and engage
the public in discourse on sustainable development. Action is needed to develop
appropriate methodologies, train a new cadre of sustainability professionals and build
institutional capacity. The task is no less than forging a new science of sustainability.

Bending the Curve: Toward Global Sustainability

73

5.4 Symptoms and Causes: A Framework for Guiding Policy
We have associated the unsustainability of the current global trajectory with three major
trends:•environmental degradation and resource depletion;•

increasing income disparity; and•poverty and marginalization.

Each defines a major area for policy attention. A set of proximate drivers isimmediately responsible for propelling and regenerating these trends. Ultimate drivers
condition the proximate drivers. For example, water pollution from factories depends
directly on the process technology in use, the volume and pattern of industrial activity, andprevailing regulation and economic incentives. Ultimately, these depend on the valuesociety puts on environmental quality, the lobbying power of interested parties,
consumption patterns setting the demand for the industry’s products, and the scientificunderstanding of the causes, impacts, and dynamics of water pollution.
A structure for critical trends and their drivers is introduced in Figure 24. The“critical trends” are associated with the Reference scenario. The “proximate drivers”
draw attention to the direct levers of change that define Policy Reform variations. The“ultimate drivers” refer to the shape of the fundamental structure of values, knowledge
and empowerment that, if suitably altered, could initiate a Great Transition scenario.
Though the distinction is not always sharp, the grouping of drivers into proximate andultimate categories is useful for discussing policies and priorities. Proximate drivers
include those factors that have a direct influence on trends, and are subject to short-term
policy intervention. Ultimate drivers are more stable and are a subject for the long-term
policy-making agenda: they tend to influence trends indirectly by acting upon proximate
drivers.
Instances of ultimate drivers, proximate drivers, and critical trends can be seen at
different spatial levels from the local to the global. At each level, the analysis of criticaltrends and drivers will provide the framework for developing effective policy strategies.
Each level requires its own analysis, and each will require disaggregation of the broad
categories mentioned below in order to gain sufficient precision.

ULTIMATE
DRIVERSPROXIMATE
DRIVERSCRITICALTRENDS

74

Raskin, Gallopin, Gutman, Hammond and Swart

Environmental
degradation andresource depletion

Increasing
incomedisparity

Poverty andmarginalization

Population sizeand growth

Economic
volume andpattern

TechnologicalchoiceEnvironmental
quality

GovernanceValues, desires
and aspirations

Structure ofpower

Human needs

Knowledge andunderstanding

Long-term
ecologicalprocesses

Figure 24. Unsustainability Trends and Drivers

With reference to Figure 24, the major proximate drivers requiring policy attention
include:• Population size and growth. Population size is a major determinant of total pressure
on the environment and resources. Population density often correlates to local
environmental pressure. Rapid rates of population growth tax the capacity of
governments to provide adequate infrastructure and services. The stresses are manifest
in developing regions in both burgeoning urban centers and zones of rural poverty.

Bending the Curve: Toward Global Sustainability

75• Economic volume and pattern. All else equal, the bigger the economy, the larger thethroughput of material resources and energy. Levels of natural resource consumption
and waste production tend to correlate with the level of economic output. The detailed
relationship is closely linked to the pattern of consumption, lifestyles, income
distribution, and poverty.
• Technological choice. The choice of technology — the means by which societies,
organizations and individuals accomplish tasks — influences the environmental andsocial impact per unit of production or consumption. Eco-efficient production
technologies play a major role in formulating Policy Reform scenarios, as do the choiceof consumption technologies, e.g., use of recycled and resource-efficient products. The
choice of technology depends on engineering criteria, cost, and cultural preference.
• Governance. Construed broadly, governance includes the aggregate of processes,
systems, relationships, and arrangements by which human communities interact, boththrough governments and non-governmental mechanisms.
Current governancestructures are a serious obstacle to sustainable development in many countries. At
national and regional levels, institutional and legal fragmentation undermines thedevelopment of the integrated policy responses required for a transition to a Policy
Reform scenario.
Inappropriate allocation mechanisms contribute both toenvironmental degradation and to poverty (e.g., land tenure systems in some parts of
the world foster deforestation and impoverishment). Meanwhile, global systems ofgovernance are struggling to cope with the immense challenges of economic
globalization and transnational environmental threats.
• Environmental quality.
Poor soils, extreme climate, or fragile ecosystems
characterize some areas of the world. These conditions may either be natural or the
result of human-induced environmental degradation. Many of the rural poor live inresource-poor and fragile lands, while often the urban poor are confined to the mostpolluted areas. Impoverishment and low environmental quality can combine in a
downward spiraling process.
Human action can address certain aspects ofenvironmental quality through environmental restoration efforts and the reduction ofpressure on environmental systems.
The categories of ultimate drivers introduced in Figure 24 are:• Values, desires and aspirations. The prevailing values in a society set the criteria for
individual ambition, ethics and aesthetic sensibility. Values are culturally conditioned,
defining the social consensus on what is considered normal or desirable. Depending on
the underlying values, a society will be characterized somewhere along a spectrum
between a sense of common purpose and antagonism, between social solidarity andindividualism, between materialism and a concern for deeper meaning. Consumerism isa significant value in shaping current trends and driving human desires and aspirations
in directions that appear to be unsustainable. A sense of solidarity with both current
and future generations, were it to become a defining global value, would form themotivational basis for a transition to sustainable development.

76

Raskin, Gallopin, Gutman, Hammond and Swart• Human needs. Here, we include material needs, such as for food and shelter, as well
as non-material needs, such as for love and meaning. Fundamental human needs — thegeneric human requirements for health — are invariable and universal. But the specificelements to satisfy them are to a high degree culturally determined. Policies cannot
modify underlying human needs, but they can affect the choice of specific “satisfiers.”
Furthermore, advertising and the media can influence the creation of wants and theirconversion into felt needs.
• Knowledge and understanding. The scientific enterprise — the formal organizationof knowledge into theory and observation — shapes both the world view of modern
societies and the capacity to manipulate natural and social systems. The evolution ofscience to reflect the complexity, holism and normative character of the sustainability
problem could be both a harbinger and a driver of change. In addition, informal
knowledge — the manner in which people perceive and make sense of their conditions
as individuals and participants in society — is critical in influencing behavior andresponses to changing circumstances. Culture, education, and the media are importantin shaping understanding.
• Structure of power. The control of resources, influence, and decision-making
authority defines the power structure. The structure circumscribes the limits of thepossible, particularly for the non-powerful, and sets priorities for society. It influences
allocation and redistribution processes, and, through the media, even shapes humanvalues, preferences, and consumption patterns. A notable property of the current
global power structure is its pronounced international asymmetry.
• Long-term ecological processes. Ecological processes mold the physical backgroundagainst which human trends and scenarios play out. These include long-term
evolutionary processes; short-term natural changes and disturbances such as hurricanes
and volcanic eruptions; and natural cycles such as seasonal variations or El Niño
events. At this stage of history, the human footprint on the environment has grown toa point where global ecology is significantly disturbed. Notable are the severe impacts
on biodiversity loss and the perilous modification of the global climate system due togreenhouse gas emissions.
Policy Reform scenarios examine the instrumental changes that are needed without
altering fundamental values and institutions. The focus is on redirecting the proximate
drivers through economic reform, regulation, redistribution, and technological initiative.
Whether this would suffice is an open question. The ultimate drivers concern the basic
character of human motivation and social structure. The greater challenge of addressing
ultimate drivers is left for Great Transition scenarios.

5.5 Policy Directions
As its name implies, the Policy Reform scenario has numerous implications for policy
making. Targets for poverty alleviation, international economic convergence, social
equity, and the environment set specific goals for the sustainability transition. Social goals
are represented, for example, by a call to reduce the hungry population to one quarter ofcurrent figures by the middle of the 21st century, and patterns of convergent development

Bending the Curve: Toward Global Sustainability

77

both between and within economic regions. Environmental goals are expressed in termsof regional targets, such as carbon emission levels with convergence toward equal per
capita emissions. The Policy Reform scenario defines directions for change: the issue now
becomes choosing the set of policy instruments that can help steer development in thesame direction.
Innumerable policy proposals for sustainable development have been put forward.
The array of options for attaining social objectives is summarized in Table 6 and forenvironmental objectives in Table 7. Within each of these aggregate policy categories,
there is an enormous variety of specific alternatives and variations. Specific sectoral
initiatives are suggested in Section 4. It is encouraging that many of the instruments are
currently being employed at local, national or international levels. Yet, policy packages do
not have the necessary breadth and depth required for a transition to sustainable
development. While success stories exist — the international ban on ozone-depleting
substances, the worldwide reduction in lead use, the significant increase in life expectancy
among developing countries’ populations — much more is needed for global changes on
the scale of a Policy Reform scenario.
Table 6. Policy Instruments to Attain the Proposed Social Objectives• International income transfers through multilateral or bilateral official development
assistance, special international funds, and voluntary donations mobilized by UN agencies,
charities, NGOs, and others.
• International agreements to safeguard the rights of the poor from, e.g., child exploitationand trade, labor and migration discrimination.
• National income transfers through public taxes and subsidies, and voluntary donations
mobilized by charities, NGOs, and others.
• Economic growth stimulation in less developed countries through international assistanceprograms, trade arrangements, capacity building, and a variety of national structural adjustment
efforts (note that social objectives are addressed only to the extent that increased income
inequality does not negate the benefits of overall growth accruing to the poor).
• Social empowerment measures to recognize the rights of women, minorities, and children.
• Investment in people ("human capital") through education, health care, and training.
• Participation by new social actors through encouragement of communities, grass roots
organizations and NGO initiatives, and provision of mechanisms for taking part in decisionmaking.
• Access of the poor to productive assets and income generating opportunities through avariety of steps including land and natural resources tenure, technology transfer, infrastructure
investment such as transport and storage facilities, and credit and marketing services targeted
for poor producers.
• Solidarity policies ("safety nets") for disadvantaged groups such as destitute households, poor
children, the sick, the handicapped and the elderly.
• Persuasion efforts to promote solidarity values conducted by governments, religious groups,
NGOs, advocacy organizations, and others through formal and informal education, information
provision, public debate, media programming, etc.

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Table 7. Policy Instruments to Attain the Proposed Environmental Objectives• International agreements on treatment of global commons, biodiversity, and resource andtechnology transfers.

• Environmental codes of conduct associated with international commerce, investment, tourism,
transport, migration, biodiversity uses, etc.

• Reactive regulations, laws and rules that discourage known environmental disruption (e.g.,
regulation to control pollution and natural resource depletion).

• Proactive regulations, laws and rules that encourage the introduction of sustainable practices(e.g., measures that foster energy efficiency, recycling and clean technologies, biodiversity andnatural resource conservation).

• Scientific and technological development for a) pollution prevention, b) clean production andconsumption technologies, c) sustainable use of natural environments and resources, d)deepening the understanding of environment and society interactions, and e) enhancing decision
making tools (e.g., green accounting, long range assessment, EIA).

• Green budgets which use fiscal measures as a lever to promote environmental goals, including:a) directing public expenditure to ecologically-friendly products (e.g., efficient technologies,
recycled products), b) using pollution and natural resource depletion taxes ("eco-taxes") as a
primary source of public revenue, and c) moving subsidies from activities that foster resource
inefficiency and environmental degradation to those that promote sustainability.

• Social empowerment policies that acknowledge and support traditional property rights of local
and indigenous communities and traditional sustainable uses of biodiversity.

• Persuasion efforts to promote environmental sustainability values conducted by governments,
religious groups, NGOs, advocacy organizations, and others through formal and informal
education, information provision, public debate, media programming, etc.

• Economic policies to motivate sustainable behavior based on individual and corporate
economic self-interest, and to use market allocation mechanisms to attain environmental goals
in an economically efficient manner, including:„ full pricing of environmental goods and services ("internalization of externalities") through a)charges or royalty fees on pollution, production, resource extraction, or resource development,b) ecological taxes, c) deposit-refund systems, bond and deposit systems, and d) import tariffs
and export taxes.
„ stimulation of environmental markets through a) tradable permits for pollution and resourceuse, b) assigning property rights to own, use, or develop resources, and c) liability andinsurance markets.
„ distribution of subsidies through a) tax breaks, b) tax differentials, c) exemptions fromcharges, d) grants, e) soft loans, f) accelerated depreciation allowances, etc.

There is no single best package of options. Rather, diverse approaches will beneeded that are appropriate to the issue, level of governance and local concerns. A
number of considerations come into play such as social and political acceptability,
economic efficiency, implementation and enforcement hurdles, equity impacts and theBending the Curve: Toward Global Sustainability

79

local environmental features. Many of these concerns are specific to national and local
contexts, and cannot be properly addressed from the global perspective assumed here.
Nevertheless, the global scenario approach can offer the following important guidelines forformulating policies for the transition:• Seek consistency across sectors. A complex and interacting set of processes that span
environmental, economic, technological, social, cultural, and political dimensions drive
the global system. Policies aimed at one aspect, such as poverty alleviation, may
exacerbate other problems, such as environmental degradation. Contradictory sectoral
policies can negate one another or backfire. Scenario analysis helps identify
opportunities for mutual reinforcement between sectoral policies. For example, thePolicy Reform scenario provides a guide for avoiding measures for environmentally
sustainable goals that are at the expense of the poor, or that promote social goals in anenvironmentally unsustainable way. Similarly, the need for compatibility and synergy
between initiatives in agriculture, water and energy sectors is underscored in the
integrated scenario analysis.
• Aim for spatial integration while recognizing local diversity. Policies need to beconsistent across scales, as well as across sectors. For instance, national policies
should neither inhibit local initiatives, nor undermine global policies. Moreover, sinceeach human community and ecosystem is unique, policies should allow for andencourage adaptations to the local context and conditions. Again, the integrated
scenario approach can illuminate the requirements for a multilevel policy framework.
• Harmonize short-term and long-term outlooks. A long time horizon is an obvious
requirement for policies that aim to affect development over many decades. But longterm policy is often, by default, the cumulative result of a series of policies with ashorter-term outlook. Therefore, short-term policies should be designed and assessed
for their long-range impacts. Alternative policies may achieve similar short-term goals
but have very different long-term impacts. Ideally, policies should create a platform forthe next round of new and more advanced policies. The scenario approach isparticularly appropriate for incorporating long-term considerations into today’s policy
discussions.
• Preserve flexibility and future options. Due to the many uncertainties inherent in theunfolding future, flexibility and adaptability to change is critical for the design ofresilient policies. Wherever possible, major policy proposals should be assessed in thisregard, and scenario techniques can help in doing so.
• Promote pluralism. As we have noted, new social actors are becoming increasingly
important, complementing traditional modes of decision-making and action. In
particular, NGOs encompass a dizzying variety of interests including educationalorganizations, trade unions, religious organizations, charities, and media. While
governments must shoulder their responsibility for confronting the challenge of thesustainability transition, the policy process should involve and mobilize all relevant
institutions, tapping into their diverse capacity and potential for interaction, synergy
and complementarity. This means that participation, negotiation and the articulation ofmultiple goals should substitute for antagonism and exclusion. Again, a scenario-

80

Raskin, Gallopin, Gutman, Hammond and Swartbuilding process that can cultivate contrasting visions and perspectives is a criticaltechnique for fostering pluralistic dialogue.
The Policy Reform scenario focuses on policies for adjusting the current trends,
not on a fundamental alteration in institutions and values. Nevertheless, sustainability
policy must be open to opportunities for addressing the evolution of what we have called
ultimate drivers, as well. An appreciation of the interplay between immediate and ultimate
causes is important to the design of the appropriate policy instruments, sinceenvironmental problems can have similar symptoms but different causes. For instance,very different policy instruments are necessary when land erosion is driven by thecommercial search for short-term profits, instead of by the survival needs of the poor.
Regulations or economic incentives can discourage environmentally disruptive practices,while education for new social values can change behaviors.

5.6 Conventional Worlds and Beyond
The lesson of the Conventional Worlds-Reference scenario is not that the world will
inevitably follow an unsatisfactory development path in the absence of proactive policy
interventions. Even without action, it is possible that unforeseen surprises, feedbacks andadaptations could mitigate the social and environmental pressures of the Reference world— or exacerbate them. The message is, rather, that there are deepening risks anduncertainties, and that complacency is not a valid option for those who believe that
passing on a more secure future is a moral imperative.
The discussion of Conventional Worlds-Policy Reform scenarios brought both
good news and bad news. The good news is that making great strides toward thesustainability transition does not require that we posit either a social revolution or the deus
ex machina of a technological miracle. Though there are numerous constraints andchallenges, the cumulative effects of a comprehensive family of feasible incremental
adjustments can make a substantial difference. An evolutionary process that promotes
appropriate technology, improved environmental management and greater internationaland social equity would take us a long way. The bad news is that Policy Reform
scenarios do require a strong postulate — the hypothesis of sufficient political will. They
assume that an unprecedented commitment arises for achieving sustainability goals, andthat effective economic, social and institutional reforms are introduced for achieving them.
The hypothesis poses critical questions for the Policy Reform route to the sustainability
transition. Can today’s nascent political formations acting on behalf of sustainability
overcome the resistance of special interests, the myopia of narrow outlooks, and theinertia of complacency? Or are fundamental changes required in values and lifestyles thattranscend Conventional Worlds assumptions — a Great Transition?
These basic questions will be addressed in the struggle over the design andimplementation of specific actions. The scenario approach reminds us that there is morethan one route to sustainability, and that a successful transition does not depend on aworld-wide endorsement of any blueprint. We see before us a process of social
discussion, of forging alliances to foster the implementation of short and medium term
agendas, and of the ascendancy of new values in the long run. Progress will probably not
be linear — social and environmental surprises are likely to jolt the world system andBending the Curve: Toward Global Sustainability

81reorient public awareness. Slowly a consensus can be built for an agenda to avoid majorsocial and environmental disruptions. This generation will bestow the gift of choice toposterity if it can begin to bend the curve of development toward sustainability.

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Programme of Action. New York: United Nations.

Bending the Curve: Toward Global Sustainability

A-1

Annex - Scenario Highlights
DEMOGRAPHY
Sheet D-1. Population ............................................................................................................. A-3
Sheet D-2. Urbanization.......................................................................................................... A-4

ECONOMY
Sheet E-1. GDP....................................................................................................................... A-5
Sheet E-2. Structure of GDP.................................................................................................... A-6
Sheet E-3. Income................................................................................................................... A-7

SOCIETY
Sheet S-1. Income Distribution................................................................................................ A-8
Sheet S-2. Hunger ................................................................................................................... A-9

ENERGY
Sheet En-1. Primary Energy Requirements by Region ........................................................... A-10
Sheet En-2. Primary Energy Requirements by Source............................................................ A-11
Sheet En-3. Final Fuel Demand by Region ............................................................................ A-12
Sheet En-4. Final Fuel Demand by Sector ............................................................................. A-13
Sheet En-5. Fossil Fuel Reserves ........................................................................................... A-14

FOOD AND AGRICULTURE
Sheet F-1. Diets..................................................................................................................... A-15
Sheet F-2. Meat and Milk Requirements and Production ....................................................... A-16
Sheet F-3. Fish Requirements and Production ....................................................................... A-17
Sheet F-4. Crop Requirements and Production ...................................................................... A-18
Sheet F-5. Cereal Yields........................................................................................................ A-19
Sheet F-6. Cropland .............................................................................................................. A-20
Sheet F-7. Irrigation.............................................................................................................. A-21
Sheet F-8. Potential Cultivable Land ..................................................................................... A-22

ENVIRONMENTAL PRESSURE
Sheet P-1. Water Withdrawals by Region .............................................................................. A-23
Sheet P-2. Water Withdrawals by Sector ............................................................................... A-24
Sheet P-3. Water Stress ......................................................................................................... A-25
Sheet P-4. Carbon Emissions................................................................................................. A-26
Sheet P-5. Sulfur Emissions .................................................................................................. A-27
Sheet P-6. Land-Use by Land Type........................................................................................ A-28
Sheet P-7. Land-Use by Region ............................................................................................. A-29
Sheet P-8. Fertilizer Consumption......................................................................................... A-31
Sheet P-9. Fisheries............................................................................................................... A-32
Sheet P-10. Toxic Waste ....................................................................................................... A-33

ABBREVIATIONS ............................................................................................................. A-35
SELECTED CONVERSION FACTORS .......................................................................... A-35
DATA NOTES ................................................................................................................... A-37

A-2

Raskin, Gallopin, Gutman, Hammond and SwartBending the Curve: Toward Global Sustainability

A-3

Sheet D-1. Population
Growth Rates - Reference

Population - Reference
10,000AfricaAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

China +

8,000

Latin America

millions

Middle East
S+SE Asia
E. Europe

6,000

4,000

FSU

25-50
95-25

N. America
Pacific OECD

2,000

W. Europe

-1.0

0.0

1.0
%/year

2.0

3.0

0
1995

2025

2050

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Population (millions)
1995
2025
2050
719
1,454
2,046
1,330
1,642
1,704
477
689
810
178
365
499
1,677
2,479
2,925
99
97
92
293
297
291
297
369
384
149
154
146
467
492
469
4,382
6,630
7,985
392
394
383
913
1,015
998
5,687
8,039
9,367

Growth Rate (%/year)
95-25
25-50
95-50
2.4
1.4
1.9
0.7
0.1
0.5
1.2
0.6
1.0
2.4
1.3
1.9
1.3
0.7
1.0
-0.1
-0.2
-0.1
0.0
-0.1
0.0
0.7
0.2
0.5
0.1
-0.2
0.0
0.2
-0.2
0.0
1.4
0.7
1.1
0.0
-0.1
0.0
0.4
-0.1
0.2
1.2
0.6
0.9

Index (95=1)
2025
2050
2.0
2.8
1.2
1.3
1.4
1.7
2.1
2.8
1.5
1.7
1.0
0.9
1.0
1.0
1.2
1.3
1.0
1.0
1.1
1.0
1.5
1.8
1.0
1.0
1.1
1.1
1.4
1.6

Population (millions)
1995
2025
2050
719
1,425
1,944
1,330
1,609
1,619
477
676
770
178
358
474
1,677
2,430
2,779
99
95
87
293
291
277
297
369
384
149
154
146
467
492
469
4,382
6,498
7,586
392
386
364
913
1,015
998
5,687
7,899
8,948

Growth Rate (%/year)
95-25
25-50
95-50
2.3
1.3
1.8
0.6
0.0
0.4
1.2
0.5
0.9
2.4
1.1
1.8
1.2
0.5
0.9
-0.1
-0.3
-0.2
0.0
-0.2
-0.1
0.7
0.2
0.5
0.1
-0.2
0.0
0.2
-0.2
0.0
1.3
0.6
1.0
-0.1
-0.2
-0.1
0.4
-0.1
0.2
1.1
0.5
0.8

Index (95=1)
2025
2050
2.0
2.7
1.2
1.2
1.4
1.6
2.0
2.7
1.4
1.7
1.0
0.9
1.0
0.9
1.2
1.3
1.0
1.0
1.1
1.0
1.5
1.7
1.0
0.9
1.1
1.1
1.4
1.6

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

A-4

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet D-2. Urbanization
100

1995
2025
2050

Percent

80
60
40
20

RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Urbanization (%)
1995
2025
34
54
31
54
74
84
58
72
31
48
62
76
66
75
76
85
78
82
75
85
37
56
65
75
76
84
45
61

2050
69
69
90
80
62
80
80
88
87
90
70
80
89
72

W. Europe

Pacific
OECD

N. America

FSU

E. Europe

S+SE Asia

MiddleEast

Latin
America

China +

Africa-Bending the Curve: Toward Global Sustainability

A-5

Sheet E-1. GDP

billion US$PPP

150,000

AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

100,000

50,000

0
1995

2025
2050
Reference

2025

2050

Policy Reform

Reference
GDP (billion US$)RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

MER
1995
475
893
1,651
522
1,769
274
528
7,464
5,544
9,085
5,310
802
22,09428,205

1995
1,165
3,839
2,858
938
4,329
588
1,206
7,995
3,146
7,352
13,1291,794
18,49333,416

PPP
2025
2050
3,958
9,279
12,09922,555
7,449
14,071
3,159
6,554
14,16030,745
1,039
1,396
2,197
3,032
18,55228,016
6,082
8,524
14,422
20,95340,82583,2043,236
4,427
39,05657,492
83,117 145,124

Growth Rate (%/year)
95-25
25-50
95-50
4.2
3.5
3.8
3.9
2.5
3.3
3.2
2.6
2.9
4.1
3.0
3.6
4.0
3.1
3.6
1.9
1.2
1.6
2.0
1.3
1.7
2.8
1.7
2.3
2.2
1.4
1.8
2.3
1.5
1.9
3.9
2.9
3.4
2.0
1.3
1.7
2.5
1.6
2.1
3.1
2.3
2.7

Index (95=1)
2025
2050
3.4
8.0
3.2
5.9
2.6
4.9
3.4
7.0
3.3
7.1
1.8
2.4
1.8
2.5
2.3
3.5
1.9
2.7
2.0
2.8
3.1
6.3
1.8
2.5
2.1
3.1
2.5
4.3

MER
1995
475
893
1,651
522
1,769
274
528
7,464
5,544
9,085
5,310
802
22,09428,205

1995
1,165
3,839
2,858
938
4,329
588
1,206
7,995
3,146
7,352
13,1291,794
18,49333,416

PPP
2025
6,381
13,762
8,026
3,501
17,013
1,120
2,501
13,341
4,742
12,202
48,683
3,622
30,28582,590Growth Rate (%/year)
95-25
25-50
95-50
5.8
3.9
4.9
4.3
2.5
3.5
3.5
2.6
3.1
4.5
3.0
3.8
4.7
3.1
3.9
2.2
1.3
1.8
2.5
1.5
2.0
1.7
0.9
1.3
1.4
0.6
1.0
1.7
0.7
1.2
4.5
3.0
3.8
2.4
1.4
1.9
1.7
0.7
1.2
3.1
2.2
2.7

Index (95=1)
2025
2050
5.5
14.1
3.6
6.6
2.8
5.3
3.7
7.9
3.9
8.4
1.9
2.6
2.1
3.0
1.7
2.1
1.5
1.7
1.7
2.0
3.7
7.7
2.0
2.9
1.6
2.0
2.5
4.3

Policy Reform
GDP (billion US$)RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

2050
16,42725,36815,177
7,383
36,4171,533
3,610
16,494
5,451
14,524
100,772
5,143
36,468142,383

A-6

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet E-2. Structure of GDP
1995

2050 - Policy Reform

100%

Services
Industry
Agriculture

Share of GDP

80%

60%

40%

World

W. Europe

N. America

Pacific OECD

FSU

E. Europe

S+SE Asia

Middle East

Latin America

AfricaWorld

W. Europe

Pacific OECD

FSU

N. America

E. Europe

S+SE Asia

Middle East

Latin America

AfricaChina +

0%China +

20%

Reference
Share of GDP (%)
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Agriculture
21
20
11
18
21
10
12
2
2
11
18
11
6
11

1995
Industry
31
47
32
37
34
38
38
27
37
28
37
38
29
33

Services Agriculture
47
15
34
10
57
8
44
12
45
11
52
7
51
8
72
1
61
1
61
6
44
11
51
8
65
3
56
7

2025
Industry
31
42
31
35
33
35
36
26
37
28
35
35
26
31

Services Agriculture
54
11
48
7
62
6
53
8
56
8
58
6
56
7
73
1
62
1
66
4
55
8
57
7
71
2
63
5

2050
Industry
31
36
29
33
31
32
34
25
37
28
30
31
24
28

Services
59
58
65
59
61
62
59
74
63
68
62
62
74
67

1995
Industry
31
47
32
37
34
38
38
27
37
28
37
38
29
33

Services Agriculture
47
11
34
9
57
7
44
10
45
10
52
7
51
8
72
1
61
2
61
7
44
9
51
7
65
4
56
7

2025
Industry
31
41
31
35
33
34
35
26
37
28
34
34
26
31

Services Agriculture
59
8
51
6
62
6
55
7
57
7
59
6
57
7
73
1
62
1
65
6
57
7
59
6
70
3
62
6

2050
Industry
30
33
28
31
31
30
32
25
37
28
28
29
24
27

Services
62
61
66
62
63
64
61
74
62
66
65
64
73
67

Policy Reform
Share of GDP (%)
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Agriculture
21
20
11
18
21
10
12
2
2
11
18
11
6
11

Bending the Curve: Toward Global Sustainability

A-7

Sheet E-3. Income
80,000A fricaC hina +Latin A m erica
M iddle E ast
S + S E A sia
E . E uro pe
FS U
N . A m e rica
P acific O E C D
W . E uro pe

US$ PPP/capita

60,00040,00020,000

0
1995

2025

2050

Reference

2025

2050

Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

GDP per capita (1995 US$ PPP)
1995
2025
2050
1,619
2,722
4,534
2,887
7,369
13,234
5,999
10,804
17,366
5,261
8,643
13,123
2,581
5,711
10,512
5,946
10,76015,2204,111
7,394
10,40526,94650,26572,932
21,10439,36858,544
15,72729,33744,714
2,996
6,157
10,4204,574
8,220
11,55820,24938,472
57,5895,876
10,33915,494Growth Rate (%/year)
95-25
25-50
95-50
1.7
2.1
1.9
3.2
2.4
2.8
2.0
1.9
2.0
1.7
1.7
1.7
2.7
2.5
2.6
2.0
1.4
1.7
2.0
1.4
1.7
2.1
1.5
1.8
2.1
1.6
1.9
2.1
1.7
1.9
2.4
2.1
2.3
2.0
1.4
1.7
2.2
1.6
1.9
1.9
1.6
1.8

Index (95=1)
2025
2050
1.7
2.8
2.6
4.6
1.8
2.9
1.6
2.5
2.2
4.1
1.8
2.6
1.8
2.5
1.9
2.7
1.9
2.8
1.9
2.8
2.1
3.5
1.8
2.5
1.9
2.8
1.8
2.6

GDP per capita (1995 US$ PPP)
1995
2025
2050
1,619
4,479
8,450
2,887
8,553
15,668
5,999
11,87919,717
5,261
9,774
15,561
2,581
7,001
13,106
5,946
11,835
17,596
4,111
8,590
13,041
26,94636,14742,937
21,10430,69637,437
15,727
24,82130,995
2,996
7,492
13,284
4,574
9,386
14,131
20,24929,83336,5305,876
10,456
15,912Growth Rate (%/year)
95-25
25-50
95-50
3.5
2.6
3.1
3.7
2.5
3.1
2.3
2.0
2.2
2.1
1.9
2.0
3.4
2.5
3.0
2.3
1.6
2.0
2.5
1.7
2.1
1.0
0.7
0.9
1.3
0.8
1.0
1.5
0.9
1.2
3.1
2.3
2.7
2.4
1.7
2.1
1.3
0.8
1.1
1.9
1.7
1.8

Index (95=1)
2025
2050
2.8
5.2
3.0
5.4
2.0
3.3
1.9
3.0
2.7
5.1
2.0
3.0
2.1
3.2
1.3
1.6
1.5
1.8
1.6
2.0
2.5
4.4
2.1
3.1
1.5
1.8
1.8
2.7

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

A-8

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet S-1. Income Distribution
Distributional Equity
Reference

Policy Reform

0.24

AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

L20%/H20%

0.20

0.16

0.12

0.08

0.04
1995

2025

2050 1995

2025

2050

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
World (pop. weighted)

Distributional Equity (L20%/H20%)
1995
2025
2050
0.13
0.09
0.07
0.14
0.10
0.08
0.07
0.06
0.06
0.10
0.07
0.06
0.18
0.11
0.09
0.23
0.14
0.11
0.22
0.14
0.10
0.11
0.08
0.06
0.16
0.11
0.08
0.19
0.12
0.09
0.15
0.10
0.08

Gini Coefficient
1995
2025
2050
0.42
0.46
0.50
0.38
0.44
0.47
0.50
0.51
0.52
0.45
0.49
0.51
0.34
0.41
0.45
0.29
0.37
0.42
0.30
0.38
0.43
0.43
0.47
0.51
0.36
0.43
0.47
0.33
0.41
0.45

Distributional Equity (L20%/H20%)
1995
2025
2050
0.13
0.13
0.14
0.14
0.14
0.14
0.07
0.08
0.12
0.10
0.10
0.12
0.18
0.15
0.15
0.23
0.18
0.16
0.22
0.17
0.16
0.11
0.11
0.12
0.16
0.14
0.15
0.19
0.16
0.15
0.15
0.14
0.14

Gini Coefficient
1995 2025
2050
0.42 0.42
0.39
0.38 0.38
0.38
0.50 0.47
0.41
0.45 0.44
0.41
0.34 0.36
0.37
0.29 0.33
0.35
0.30 0.34
0.36
0.43 0.43
0.40
0.36 0.37
0.37
0.33 0.36
0.36

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
World (pop. weighted)

Bending the Curve: Toward Global Sustainability

A-9

Sheet S-2. Hunger

millions of people

1,000AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

800

600

400
200

0
1995

2025

2050

2025

2050

Reference

Policy Reform

Incidence (% of population)
1995
2025
2050
34
25
20
16
9
8
14
11
9
16
16
14
19
10
8
1
2
3
4
5
6
2
1
1
1
1
0
1
1
1
20
13
12
3
4
5
1
1
1
16
11
10

Incidence (millions)
1995
2025
2050
247
361
404
211
142
136
65
73
72
29
57
72
320
259
240
1
2
3
11
14
18
7
3
2
1
1
0
4
4
4
873
893
924
12
16
21
12
8
6
898
917
951

Index (95=1)
2025
2050
1.46
1.63
0.67
0.64
1.13
1.11
1.95
2.45
0.81
0.75
2.72
4.24
1.24
1.55
0.45
0.34
0.53
0.32
1.06
0.94
1.02
1.06
1.33
1.71
0.64
0.52
1.02
1.06

Incidence (% of population)
1995
2025
2050
34
12
5
16
4
2
14
7
2
16
11
5
19
4
2
1
1
1
4
2
2
2
1
0
1
0
0
1
1
0
20
7
3
3
2
1
1
1
0
16
6
2

Incidence (millions)
1995
2025
2050
247
174
87
211
59
29
65
49
18
29
40
24
320
109
54
1
1
1
11
7
5
7
4
1
1
1
0
4
3
1
873
431
212
12
7
5
12
7
2
898
445
220

Index (95=1)
2025
2050
0.70
0.35
0.28
0.14
0.75
0.28
1.39
0.81
0.34
0.17
1.01
0.94
0.57
0.40
0.50
0.12
0.35
0.11
0.69
0.37
0.49
0.24
0.60
0.43
0.54
0.19
0.50
0.25

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

A-10

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet En-1. Primary Energy Requirements by Region
1,000

AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

EJ

800
600
400
200
0
1995

2025

2050

Reference

2025

2050

Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Primary Energy (EJ)
1995
2025
2050
17
50
98
48
105
144
24
55
84
18
38
60
43
114
205
10
13
12
45
60
64
94
138
152
23
29
31
63
76
79
150
361
591
55
73
76
179
243
262
384
677
929

Growth Rate (%/year)
95-25
25-50
95-50
3.6
2.7
3.2
2.7
1.3
2.0
2.7
1.8
2.3
2.5
1.9
2.2
3.3
2.4
2.9
0.8
-0.2
0.4
0.9
0.3
0.6
1.3
0.4
0.9
0.8
0.2
0.5
0.6
0.2
0.4
3.0
2.0
2.5
0.9
0.2
0.6
1.0
0.3
0.7
1.9
1.3
1.6

Index (95=1) Intensity (MJ/$ PPP)
2025
2050
1995
2025
2050
2.9
5.7
15
13
11
2.2
3.0
12
9
6
2.3
3.5
8
7
6
2.1
3.3
19
12
9
2.7
4.8
10
8
7
1.3
1.2
17
12
9
1.3
1.4
38
27
21
1.5
1.6
12
7
5
1.3
1.3
7
5
4
1.2
1.3
9
5
4
2.4
3.9
11
9
7
1.3
1.4
31
22
17
1.4
1.5
10
6
5
1.8
2.4
12
8
6

Primary Energy (EJ)
1995
2025
2050
17
63
107
48
104
105
24
45
48
18
37
41
43
114
160
10
9
6
45
47
28
94
73
57
23
17
12
63
49
36
150
363
460
55
56
35
179
138
105
384
558
599

Growth Rate (%/year)
95-25
25-50
95-50
4.4
2.1
3.4
2.6
0.0
1.4
2.1
0.2
1.2
2.4
0.4
1.5
3.3
1.4
2.4
-0.3
-1.4
-0.8
0.1
-2.0
-0.9
-0.8
-1.0
-0.9
-1.0
-1.3
-1.2
-0.8
-1.3
-1.0
3.0
0.9
2.1
0.1
-1.9
-0.9
-0.9
-1.1
-1.0
1.2
0.3
0.8

Index (95=1)
2025
2050
3.7
6.2
2.2
2.2
1.9
2.0
2.1
2.3
2.7
3.8
0.9
0.7
1.0
0.6
0.8
0.6
0.7
0.5
0.8
0.6
2.4
3.1
1.0
0.6
0.8
0.6
1.5
1.6

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Intensity (MJ/$ PPP)
1995
2025
2050
15
10
6
12
8
4
8
6
3
19
11
6
10
7
4
17
8
4
38
19
8
12
5
3
7
4
2
9
4
2
11
7
5
31
16
7
10
5
3
12
7
4

Bending the Curve: Toward Global Sustainability

A-11

Sheet En-2. Primary Energy Requirements by Source
100%

fuel share

Coal
80%

Crude Oil60%

Natural Gas
Uranium

40%

Hydropower
20%

Renewables

0%
1995

2025

2050

Reference

2025

2050

Policy Reform

Reference
Fuel
Coal
Crude OilNatural Gas
Uranium
Hydropower
Renewables
Total

Primary Energy (EJ)
1995
2025
2050
95
166
224
141
256
332
73
136
203
25
39
64
9
16
20
41
64
87
384
677
929

Share of Total (%)
1995
2025
2050
25
25
24
37
38
36
19
20
22
7
6
7
2
2
2
11
9
9
100
100
100

Growth Rate (%/year)
95-25
25-50
95-50
1.9
1.2
1.6
2.0
1.0
1.6
2.1
1.6
1.9
1.5
2.0
1.7
1.9
0.9
1.4
1.5
1.3
1.4
1.9
1.3
1.6

Index (95=1)
2025
2050
1.8
2.4
1.8
2.3
1.9
2.8
1.5
2.5
1.7
2.2
1.6
2.1
1.8
2.4

Primary Energy (EJ)
1995
2025
2050
95
113
63
141
183
153
73
156
215
25
22
9
16
20
41
68
148
384
558
599

Share of Total (%)
1995
2025
2050
25
20
11
37
33
26
19
28
36
7
4
2
3
3
11
12
25
100
100
100

Growth Rate (%/year)
95-25
25-50
95-50
0.6
-2.3
-0.7
0.9
-0.7
0.1
2.6
1.3
2.0
-0.4
1.9
0.9
1.4
1.7
3.2
2.4
1.2
0.3
0.8

Index (95=1)
2025
2050
1.2
0.7
1.3
1.1
2.1
2.9
0.9
0.0
1.7
2.2
1.7
3.6
1.5
1.6

Policy Reform
Fuel
Coal
Crude OilNatural Gas
Uranium
Hydropower
Renewables
Total

A-12

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet En-3. Final Fuel Demand by Region
700

AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

600

EJ

500
400
300
200
100
0
1995

2025

2050

Reference

2025

2050

Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Final Energy Demand (EJ)
1995
2025
2050
13
35
66
37
77
103
18
39
56
9
26
42
33
82
143
6
8
8
29
40
42
64
101
112
17
19
20
46
55
58
109
260
409
36
48
50
126
176
190
272
483
649

Growth Rate (%/year)
95-25
25-50
95-50
3.3
2.6
3.0
2.5
1.1
1.9
2.7
1.4
2.1
3.7
2.0
2.9
3.1
2.2
2.7
0.8
-0.1
0.4
1.0
0.2
0.7
1.5
0.4
1.0
0.5
0.1
0.3
0.6
0.2
0.4
2.9
1.8
2.4
1.0
0.2
0.6
1.1
0.3
0.7
1.9
1.2
1.6

Index (95=1)
2025
2050
2.7
5.1
2.1
2.8
2.2
3.2
2.9
4.8
2.5
4.3
1.3
1.2
1.4
1.4
1.6
1.7
1.2
1.2
1.2
1.3
2.4
3.7
1.3
1.4
1.4
1.5
1.8
2.4

Intensity (MJ/$ PPP)
1995
2025
2050
11
9
7
10
6
5
6
5
4
9
8
6
8
6
5
11
8
6
24
18
14
8
5
4
5
3
2
6
4
3
8
6
5
20
15
11
7
4
3
8
6
4

Final Energy Demand (EJ)
1995
2025
2050
13
46
84
37
76
80
18
37
37
9
26
33
33
88
129
6
6
5
29
37
24
64
59
47
17
13
9
46
38
29
109
272
363
36
43
29
126
109
85
272
425
476

Growth Rate (%/year)
95-25
25-50
95-50
4.3
2.4
3.4
2.5
0.2
1.4
2.5
0.0
1.4
3.7
1.0
2.5
3.3
1.5
2.5
0.1
-1.0
-0.4
0.7
-1.7
-0.4
-0.3
-0.9
-0.6
-0.9
-1.2
-1.0
-0.6
-1.1
-0.8
3.1
1.2
2.2
0.6
-1.6
-0.4
-0.5
-1.0
-0.7
1.5
0.5
1.0

Index (95=1)
2025
2050
3.5
6.4
2.1
2.2
2.1
2.1
2.9
3.8
2.6
3.9
1.0
0.8
1.2
0.8
0.9
0.7
0.8
0.6
0.8
0.6
2.5
3.3
1.2
0.8
0.9
0.7
1.6
1.8

Intensity (MJ/$ PPP)
1995
2025
2050
11
7
5
10
6
3
6
5
2
9
7
5
8
5
4
11
6
3
24
15
7
8
4
3
5
3
2
6
3
2
8
6
4
20
12
6
7
4
2
8
5
3

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Bending the Curve: Toward Global Sustainability

A-13

Sheet En-4. Final Fuel Demand by Sector
100%

fuel share

Agriculture
80%

Households

60%

Industry
Services

40%

Transport
20%
0%
1995

2025
2050
Reference

2025
2050
Policy Reform

Reference
SectorAgriculture
Households
Industry
Services
Transport
Total

Final Energy Demand (EJ)
1995
2025
2050
8
11
14
72
102
123
104
188
250
19
34
58
69
147
204
272
483
649

Share of Total (%)
1995
2025
2050
3
2
2
27
21
19
38
39
39
7
7
9
25
30
31
100
100
100

Growth Rate (%/year)
95-25
25-50
95-50
1.1
1.0
1.0
1.2
0.7
1.0
2.0
1.1
1.6
2.1
2.1
2.1
2.6
1.3
2.0
1.9
1.2
1.6

Index (95=1)
2025
2050
1.4
1.8
1.4
1.7
1.8
2.4
1.9
3.1
2.1
3.0
1.8
2.4

Final Energy Demand (EJ)
1995
2025
2050
8
10
12
72
102
116
104
175
184
19
29
44
69
108
121
272
425
476

Share of Total (%)
1995
2025
2050
3
2
3
27
24
24
38
41
39
7
7
9
25
26
25
100
100
100

Growth Rate (%/year)
95-25
25-50
95-50
0.9
0.6
0.8
1.2
0.5
0.9
1.7
0.2
1.0
1.5
1.7
1.6
1.5
0.4
1.0
1.5
0.5
1.0

Index (95=1)
2025
2050
1.3
1.5
1.4
1.6
1.7
1.8
1.6
2.4
1.6
1.8
1.6
1.8

Policy Reform
SectorAgriculture
Households
Industry
Services
Transport
Total

A-14

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet En-5. Fossil Fuel Reserves
Conventional Crude Oil
10^12 cubic meters

billion barrels

2,000
1,500
1,000
500
0
1995

ProvenConventional Natural Gas

2,500

300
Proven +Undiscovered

200
Policy Reform
Cumulative
Consumption
Reference
Cumulative
Consumption

100

2025

1995

2050

Uranium

2025

2050

C oal

7,000

2,000

5,000

billion tonnes

thousand tonnes

6,000
4,000
3,000
2,000

1,500
1,000
500

1,000
0
1995

2025

0
1995

2050

2025

2050

Total Remaining Reserves
Proven + Undiscovered, 1995
Coal
RegionAfricaChina+
Latin America
Middle East
S+SE Asia
E Europe
FSU
N America
Pacific OECDW Europe
Developing
Transitional
OECD
World
World (EJ)

9(10 t)
62
265
20
0
151
92
241
249
525
105
499
333
879
1,711
51,336

Crude Oil9

(10 barrels)
84
276
407
670
24
2
58
45
3
25
1,461
60
73
1,594
9,279

Natural Gas
(10

12

3)

m
15
4
20
80
13
2
91
21
2
8
131
92
31
254
8,900

Uranium
3(10 t)
1,142
5
174
57
21
799
926
157
1,378
21
1,881
3,281
1,102

Share of Reserves (%)
Coal
4
16
1
0
9
5
14
15
31
6
29
19
51
100

Crude Oil Natural Gas
5
6
17
2
26
8
42
31
2
5
0
1
4
36
3
8
0
1
2
3
92
52
4
36
5
12
100
100

Uranium
35
0
5
2
1
24
28
5
42
1
57
100

Bending the Curve: Toward Global Sustainability

A-15

Sheet F-1. Diets
Average Daily Consumption
AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

average daily kcal/capita

3,400

3,000

2,600

2,200
1995

2025

2050

Reference

2025

2050

Policy Reform

R eferen ce
R eg ion
A fric a
C hin a +L atin A m e rica
M idd le E a st
S + S E A s ia
E . E uro pe
FSU
N . A m e ric a
P a cific O E C D
W . E u rop e
D ev elo p ing
T ra ns itio na l
O ECD
W o rld

A v g. D aily C o n su m p tion (k c al/c a pita)
1 99 52 02 5
2 05 02 ,3 22
2 ,5 26
2 ,7 00
2 ,7 55
2 ,9 93
3 ,1 00
2 ,7 04
2 ,8 84
3 ,0 00
2 ,6 04
2 ,7 78
2 ,9 00
2 ,3 93
2 ,6 75
2 ,8 50
3 ,1 25
3 ,2 96
3 ,4 00
2 ,7 64
3 ,0 88
3 ,2 00
3 ,5 52
3 ,5 26
3 ,5 00
2 ,8 40
3 ,1 77
3 ,3 00
3 ,3 39
3 ,3 70
3 ,4 00
2 ,5 34
2 ,7 48
2 ,8 83
2 ,8 55
3 ,1 39
3 ,2 48
3 ,3 27
3 ,3 97
3 ,4 24
2 ,6 83
2 ,8 50
2 ,9 56

S h are fro m A n im al P ro d uc ts (% ca l)
1 99 52 02 5
2 05 0
7
10
13
16
19
21
18
20
22
10
14
18
8
12
16
27
29
30
25
28
30
31
30
30
24
26
28
30
30
30
12
14
17
25
28
30
29
29
30
16
17
19

Policy Reform
RegionAfricaChina +
Latin Am erica
M iddle East
S+SE Asia
E. Europe
FSU
N. Am erica
Pacific O EC D
W . Europe
Developing
Transitional
O ECD
W orld

Avg. Daily Consum ption (kcal/capita)
1995
2025
2050
2,322
2,696
2,876
2,755
3,023
3,126
2,704
2,909
3,027
2,604
2,816
2,944
2,393
2,738
2,904
3,125
3,324
3,400
2,764
3,143
3,252
3,552
3,526
3,500
2,840
3,177
3,300
3,339
3,370
3,400
2,534
2,821
2,959
2,855
3,187
3,287
3,327
3,397
3,424
2,683
2,913
3,024

Share from Anim al Products (% cal)
1995
2025
2050
7
13
17
16
20
22
18
21
22
10
15
19
8
14
17
27
29
30
25
29
30
31
30
30
24
26
28
30
30
30
12
16
19
25
29
30
29
29
30
16
19
21

A-16

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet F-2. Meat and Milk Requirements and Production
Milk and Meat Requirements
2,000

AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

million tonnes

1,500

1,000

500

0
1995

2025

2050

Reference

2025

2050

Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Requirements (million tonnes)
1995
2025
2050
41
120
232
80
159
203
86
146
196
18
50
90
117
269
435
32
35
35
95
115
125
126
152
157
30
42
47
185
201
195
343
744
1,156
127
150
160
341
394
399
811
1,288
1,715

Production (million tonnes)
1995
2025
2050
36
101
197
79
160
205
79
143
194
14
34
60
110
254
419
34
38
39
102
126
142
127
166
179
40
50
59
196
217
221
317
691
1,075
135
163
181
363
434
459
816
1,288
1,715

Self-Sufficiency Ratio
Fraction of Meat from Feedlots (%)
1995
2025
2050
1995
2025
2050
0.9
0.8
0.9
28%
32%
33%
1.0
1.0
1.0
18%
19%
20%
0.9
1.0
1.0
40%
41%
40%
0.8
0.7
0.7
75%
85%
89%
0.9
0.9
1.0
18%
21%
23%
1.1
1.1
1.1
71%
75%
76%
1.1
1.1
1.1
73%
79%
81%
1.0
1.1
1.1
70%
76%
79%
1.3
1.2
1.3
30%
45%
52%
1.1
1.1
1.1
35%
42%
46%
0.9
0.9
0.9
24%
27%
29%
1.1
1.1
1.1
72%
78%
80%
1.1
1.1
1.2
49%
56%
61%
1.0
1.0
1.0
37%
39%
39%

Production (million tonnes)
1995
2025
2050
36
136
261
79
172
210
79
150
187
14
36
61
110
291
429
34
38
38
102
131
140
127
168
182
40
52
60
196
220
224
317
786
1,148
135
169
178
363
440
467
816
1,394
1,793

Self-Sufficiency Ratio Fraction of Meat from Feedlots (%)
1995 2025 2050
1995
2025
2050
0.9
0.8
0.9
28%
45%
58%
1.0
1.0
1.0
18%
19%
24%
0.9
1.0
1.0
40%
42%
50%
0.8
0.7
0.7
75%
87%
92%
0.9
0.9
1.0
18%
30%
35%
1.1
1.1
1.1
71%
75%
78%
1.1
1.1
1.2
73%
80%
81%
1.0
1.1
1.2
70%
78%
82%
1.3
1.2
1.3
30%
50%
55%
1.1
1.1
1.1
35%
43%
47%
0.9
0.9
0.9
24%
31%
41%
1.1
1.1
1.2
72%
79%
80%
1.1
1.1
1.2
49%
58%
63%
1.0
1.0
1.0
37%
41%
47%

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Requirements (million tonnes)
1995
2025
2050
41
162
306
80
171
208
86
152
188
18
53
92
117
309
445
32
34
33
95
118
121
126
152
157
30
42
47
185
201
196
343
846
1,239
127
153
155
341
395
400
811
1,394
1,793

Bending the Curve: Toward Global Sustainability

A-17

Sheet F-3. Fish Requirements and Production
Fish Requirements
AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

million tonnes

150

100

50

0
1995

2025
2050
Reference

2025

2050

Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Requirements (million tonnes)
1995
2025
2050
6
15
23
31
39
40
8
13
15
2
7
11
22
36
44
1
1
1
4
5
4
9
11
11
14
14
11
16
11
9
68
109
132
5
5
5
39
37
32
113
151
170

Production (million tonnes)
1995
2025
2050
5
11
17
27
35
38
20
31
35
1
3
5
21
35
42
1
0
0
4
4
4
7
11
11
10
12
10
13
8
7
73
115
137
5
5
5
30
32
28
108
151
170

Self-Sufficiency Ratio
1995
2025
2050
0.8
0.8
0.8
0.9
0.9
0.9
2.4
2.3
2.3
0.4
0.5
0.5
1.0
1.0
1.0
0.6
0.4
0.5
1.0
1.0
1.0
0.8
1.0
1.0
0.7
0.9
0.9
0.8
0.7
0.8
1.1
1.1
1.0
0.9
0.9
0.9
0.8
0.9
0.9
1.0
1.0
1.0

Production (million tonnes)
1995
2025
2050
5
11
17
27
34
35
20
30
33
1
3
5
21
34
40
1
0
0
4
5
4
7
11
11
10
12
10
13
8
7
73
113
130
5
5
5
30
32
28
108
149
163

Self-Sufficiency Ratio
1995
2025
2050
0.8
0.8
0.8
0.9
0.9
0.9
2.4
2.4
2.3
0.4
0.5
0.5
1.0
1.0
1.0
0.6
0.4
0.5
1.0
1.0
1.0
0.8
1.0
1.0
0.7
0.9
0.9
0.8
0.7
0.8
1.1
1.1
1.0
0.9
0.9
0.9
0.8
0.9
0.9
1.0
1.0
1.0

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Requirements (million tonnes)
1995
2025
2050
6
14
22
31
38
37
8
13
15
2
7
11
22
35
41
1
1
1
4
5
4
9
11
11
14
14
11
16
11
9
68
107
126
5
5
5
39
37
32
113
149
163

A-18

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet F-4. Crop Requirements and Production
Crop Requirements
12,000AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

million tonnes

10,000
8,000
6,000
4,000
2,000
0
1995

2025
2050
Reference

2025
2050
Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Requirements (million tonnes)
1995
2025
2050
500
1,080
1,610
908
1,283
1,424
729
1,131
1,438
153
347
503
1,101
1,941
2,578
163
183
191
405
563
614
515
659
708
130
177
194
638
724
738
3,390
5,782
7,553
569
747
805
1,284
1,560
1,641
5,243
8,089
9,999

Production (million tonnes)
1995
2025
2050
438
887
1,369
864
1,228
1,412
836
1,268
1,534
95
201
273
1,094
1,917
2,562
156
211
238
310
612
691
659
821
928
101
146
157
610
798
836
3,327
5,501
7,150
466
823
929
1,369
1,765
1,920
5,162
8,089
9,999

Net Exports (million tonnes)
1995
2025
2050
-61
-193
-241
-44
-55
-12
106
137
96
-58
-146
-231
-7
-24
-16
-7
28
47
-95
48
77
144
161
219
-29
-31
-37
-29
74
97
-64
-281
-403
-103
76
124
86
204
279
-81
0
0

Self-Sufficiency Ratio
1995
2025
2050
0.9
0.8
0.9
1.0
1.0
1.0
1.1
1.1
1.1
0.6
0.6
0.5
1.0
1.0
1.0
1.0
1.2
1.2
0.8
1.1
1.1
1.3
1.2
1.3
0.8
0.8
0.8
1.0
1.1
1.1
1.0
1.0
0.9
0.8
1.1
1.2
1.1
1.1
1.2
1.0
1.0
1.0

Requirements (million tonnes) Production (million tonnes)
1995
2025
2050
1995
2025
2050
500
1,211
1,865
438
956
1,412
908
1,272
1,425
864
1,236
1,466
729
1,104
1,635
836
1,259
1,758
153
349
494
95
192
252
1,101
2,001
2,642
1,094
1,899
2,279
163
186
188
156
228
264
405
575
615
310
640
807
515
668
732
659
892
1,201
130
184
199
101
146
154
638
733
744
610
835
946
3,390
5,937
8,060
3,327
5,542
7,167
569
761
803
466
869
1,071
1,284
1,585
1,676
1,369
1,873
2,301
5,243
8,284
10,5395,162
8,284
10,539Net Exports (million tonnes)
1995
2025
2050
-61
-255
-453
-44
-36
40
106
155
124
-58
-157
-242
-7
-102
-363
-7
42
76
-95
65
192
144
224
469
-29
-39
-45
-29
103
202
-64
-395
-893
-103
107
268
86
288
626
-81
0
0

Self-Sufficiency Ratio
1995
2025
2050
0.9
0.8
0.8
1.0
1.0
1.0
1.1
1.1
1.1
0.6
0.5
0.5
1.0
0.9
0.9
1.0
1.2
1.4
0.8
1.1
1.3
1.3
1.3
1.6
0.8
0.8
0.8
1.0
1.1
1.3
1.0
0.9
0.9
0.8
1.1
1.3
1.1
1.2
1.4
1.0
1.0
1.0

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Bending the Curve: Toward Global Sustainability

A-19

Sheet F-5. Cereal Yields
AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

tonnes/hectare-year

10

8

6

4

2

0
1995

2025
2050
Reference

2025

2050

Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Harvest yield (tonnes/hectare)
1995
2025
2050
1.2
2.3
2.8
4.4
5.8
6.2
2.4
3.2
3.5
1.6
2.6
3.1
2.4
3.9
4.3
3.0
5.2
5.7
1.5
3.3
3.5
4.9
6.0
6.2
2.1
3.0
3.1
4.1
6.0
6.2
2.5
3.7
4.1
1.8
3.6
3.8
4.3
5.7
5.9
2.8
4.1
4.4

Cropping Intensity (harvests/yr)
1995
2025
2050
0.85
0.85
0.89
1.44
1.53
1.62
0.81
0.84
0.87
0.64
0.71
0.85
1.01
1.10
1.18
0.80
0.79
0.79
0.55
0.63
0.65
0.56
0.55
0.58
0.38
0.40
0.42
0.72
0.75
0.74
0.98
1.01
1.06
0.59
0.65
0.67
0.58
0.58
0.60
0.77
0.81
0.84

Annual yield (tonnes/hectare-yr)
1995
2025
2050
1.0
1.9
2.5
6.3
9.0
10.1
2.0
2.7
3.1
1.0
1.9
2.6
2.4
4.3
5.1
2.4
4.1
4.4
0.8
2.1
2.3
2.7
3.3
3.6
0.8
1.2
1.3
2.9
4.5
4.6
2.5
3.7
4.3
1.1
2.4
2.6
2.5
3.3
3.5
2.2
3.3
3.7

Index (95=1)
2025
2050
1.9
2.4
1.4
1.6
1.3
1.5
1.8
2.5
1.8
2.1
1.7
1.8
2.5
2.7
1.2
1.3
1.5
1.6
1.5
1.6
1.5
1.7
2.2
2.4
1.3
1.4
1.5
1.7

Harvest yield (tonnes/hectare) Cropping Intensity (harvests/yr) Annual yield (tonnes/hectare-yr)
1995
2025
2050
1995
2025
2050
1995
2025
2050
1.2
2.3
2.8
0.85
0.85
0.89
1.0
1.9
2.5
4.4
5.6
6.0
1.44
1.51
1.59
6.3
8.5
9.5
2.4
3.1
3.5
0.81
0.83
0.87
2.0
2.6
3.0
1.6
2.6
2.9
0.64
0.69
0.82
1.0
1.8
2.4
2.4
4.1
4.7
1.01
1.11
1.20
2.4
4.6
5.7
3.0
5.2
5.6
0.80
0.79
0.78
2.4
4.1
4.4
1.5
3.3
3.5
0.55
0.63
0.65
0.8
2.0
2.2
4.9
5.9
5.9
0.56
0.54
0.57
2.7
3.2
3.4
2.1
3.0
3.1
0.38
0.40
0.42
0.8
1.2
1.3
4.1
5.9
6.0
0.72
0.75
0.73
2.9
4.4
4.4
2.5
3.7
4.2
0.98
1.01
1.06
2.5
3.7
4.4
1.8
3.6
3.8
0.59
0.65
0.67
1.1
2.3
2.5
4.3
5.6
5.7
0.58
0.58
0.60
2.5
3.3
3.4
2.8
4.1
4.5
0.77
0.80
0.81
2.2
3.3
3.7

Index (95=1)
2025
2050
1.9
2.4
1.4
1.5
1.3
1.5
1.7
2.3
1.9
2.4
1.7
1.8
2.4
2.7
1.2
1.2
1.5
1.6
1.5
1.5
1.5
1.8
2.2
2.4
1.3
1.4
1.5
1.7

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

A-20

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet F-6. Cropland
AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

million hectares

1,500

1,000

500

0
1995

2025

2050

Reference

2025

2050

Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Total Cropland (million ha)
1995
2025
2050
186
255
277
107
110
105
144
162
176
44
46
46
289
294
309
39
38
38
228
219
226
233
225
237
55
63
65
124
122
127
770
867
913
268
256
264
412
410
429
1,450
1,534
1,606

Growth Rate (%/year)
95-25
25-50
95-50
1.1
0.3
0.7
0.1
-0.2
0.0
0.4
0.3
0.4
0.1
0.1
0.1
0.1
0.2
0.1
-0.2
0.0
-0.1
-0.1
0.1
0.0
-0.1
0.2
0.0
0.4
0.1
0.3
0.0
0.2
0.0
0.4
0.2
0.3
-0.1
0.1
0.0
0.0
0.2
0.1
0.2
0.2
0.2

Index (95=1)
2025
2050
1.4
1.5
1.0
1.0
1.1
1.2
1.0
1.1
1.0
1.1
1.0
1.0
1.0
1.0
1.0
1.0
1.1
1.2
1.0
1.0
1.1
1.2
1.0
1.0
1.0
1.0
1.1
1.1

Total Cropland (million ha)
1995
2025
2050
186
275
287
107
114
109
144
171
196
44
53
57
289
283
258
39
40
41
228
235
251
233
252
331
55
63
60
124
133
153
770
896
907
268
275
293
412
447
545
1,450
1,618
1,744

Growth Rate (%/year)
95-25
25-50
95-50
1.3
0.2
0.8
0.2
-0.2
0.0
0.6
0.5
0.6
0.6
0.3
0.5
-0.1
-0.4
-0.2
0.0
0.1
0.1
0.1
0.3
0.2
0.3
1.1
0.6
0.4
-0.1
0.2
0.2
0.6
0.4
0.5
0.1
0.3
0.1
0.2
0.2
0.3
0.8
0.5
0.4
0.3
0.3

Index (95=1)
2025
2050
1.5
1.5
1.1
1.0
1.2
1.4
1.2
1.3
1.0
0.9
1.0
1.0
1.0
1.1
1.1
1.4
1.1
1.1
1.1
1.2
1.2
1.2
1.0
1.1
1.1
1.3
1.1
1.2

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Bending the Curve: Toward Global Sustainability

A-21

Sheet F-7. Irrigation

million hectares

300

AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

200

100

0
1995

2025
2050
Reference

2025

2050

Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Irrigated Cropland (million ha)
1995
2025
2050
12
14
14
53
56
58
18
20
22
15
17
17
84
95
99
5
5
5
19
21
23
22
23
24
5
6
6
16
17
19
182
201
211
24
26
28
43
46
49
250
274
288

Index (95=1)
Fraction of Cropland Irrigated (%)
2025
2050
1995
2025
2050
1.1
1.1
7
5
5
1.1
1.1
49
51
56
1.1
1.3
12
12
13
1.1
1.1
34
37
37
1.1
1.2
29
32
32
1.1
1.2
12
14
14
1.1
1.2
8
10
10
1.0
1.1
9
10
10
1.1
1.1
9
9
9
1.1
1.2
13
14
15
1.1
1.2
24
23
23
1.1
1.2
9
10
11
1.1
1.1
11
11
11
1.1
1.2
17
18
18

Irrigated Cropland (million ha)
1995
2025
2050
12
14
14
53
56
58
18
20
22
15
14
13
84
95
99
5
5
5
19
21
23
22
23
24
5
6
6
16
17
19
182
198
206
24
26
28
43
46
49
250
271
283

Index (95=1)
Fraction of Cropland Irrigated (%)
2025
2050
1995
2025
2050
1.1
1.1
7
5
5
1.0
1.1
49
49
53
1.1
1.3
12
12
11
0.9
0.9
34
27
24
1.1
1.2
29
34
38
1.1
1.1
12
13
13
1.1
1.2
8
9
9
1.0
1.1
9
9
7
1.1
1.1
9
9
10
1.1
1.2
13
13
12
1.1
1.1
24
22
23
1.1
1.2
9
9
10
1.1
1.1
11
10
9
1.1
1.1
17
17
16

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

A-22

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet F-8. Potential Cultivable Land
Policy Reform Scenario
PCL per Capita

Cropland/PCL

3100

A fricaC hina +Latin A m erica
M iddle E ast
S + S E A sia
E . E uro pe
FS U
N . A m eric a
P acific O E C D
W . E uro pe

cro pland area /PCL a re a (% )PCL hectares/capita

80
2

1

60

40

20

0

0
1995

2025

2050

1995

2025

2050

R e fe re nc e
R egionA fricaC hina +La tin A m erica
M id dle E as t
S + S E A sia
E . E urope
FSU
N . A m eric a
P a cific O E C D
W . E urope
D eve lopin g
T ran sitio nal
O EC DW o rld

P C L (m illion ha )
19 95
20 25
20 50
1,0 771,0 24
97 8
20 6
17 8
15 3
1,0 10
98 1
95 3
59
52
47
42 0
39 1
35 6
57
56
54
71 6
71 3
71 0
70 5
69 7
69 3
33 3
33 1
33 0
22 9
22 7
22 6
2,7 722,6 262,4 87
77 3
76 8
76 4
1,2 67
1,2 54
1,2 494,8 124,6 494,5 00P C L p er cap ita (ha/ca pita)
19 95
20 25
20 50
1.5
0.7
0.5
0.2
0.1
0.1
2.1
1.4
1.2
0.3
0.1
0.1
0.3
0.2
0.1
0.6
0.6
0.6
2.4
2.4
2.4
2.4
1.9
1.8
2.2
2.1
2.3
0.5
0.5
0.5
0.6
0.4
0.3
2.0
2.0
2.0
1.4
1.2
1.3
0.8
0.6
0.5

C rop land /P C L (% )
19 95
20 25
20 50
17
25
28
52
62
68
14
16
18
75
87
99
69
75
87
69
68
70
32
31
32
33
32
34
17
19
20
54
54
56
28
33
37
35
33
35
33
33
34
30
33
36

PCL (million ha)
PCL per capita (ha/capita)
1995
2025
2050
1995
2025
2050
1,077
1,043
1,048
1.5
0.7
0.5
206
188
189
0.2
0.1
0.1
1,010
996
1,003
2.1
1.5
1.3
59
55
57
0.3
0.2
0.1
420
392
369
0.3
0.2
0.1
57
56
57
0.6
0.6
0.7
716
714
714
2.4
2.5
2.6
705
702
704
2.4
1.9
1.8
333
333
333
2.2
2.2
2.3
229
229
230
0.5
0.5
0.5
2,772
2,674
2,667
0.6
0.4
0.4
773
770
771
2.0
2.0
2.1
1,267
1,264
1,267
1.4
1.2
1.3
4,812
4,708
4,705
0.8
0.6
0.5

Cropland/PCL (% )
1995
2025
2050
17
26
27
52
61
57
14
17
20
75
96
100
69
72
70
69
71
73
32
33
35
33
36
47
17
19
18
54
58
67
28
34
34
35
36
38
33
35
43
30
34
37

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. Am erica
Pacific O ECD
W. Europe
Developing
Transitional
OECD
World

Bending the Curve: Toward Global Sustainability

A-23

Sheet P-1. Water Withdrawals by Region
AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

billion m3

6,000

4,000

2,000

0
1995

2025
2050
Reference

2025
2050
Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

3

Growth Rate (%/year)
95-25
25-50
95-50
1.4
1.5
1.5
1.0
0.8
1.0
1.4
1.3
1.4
1.4
0.9
1.2
1.3
1.0
1.1
0.6
-0.1
0.3
1.1
0.2
0.7
0.4
0.1
0.3
0.6
0.2
0.4
0.4
0.0
0.2
1.3
1.0
1.2
1.1
0.2
0.7
0.4
0.1
0.3
1.0
0.8
0.9

Index (95=1)
2025
2050
1.5
2.2
1.4
1.7
1.5
2.1
1.5
1.9
1.5
1.9
1.2
1.2
1.4
1.5
1.1
1.2
1.2
1.2
1.1
1.1
1.5
1.9
1.4
1.4
1.1
1.2
1.4
1.6

3

Growth Rate (%/year)
95-25
25-50
95-50
1.0
0.8
0.9
0.5
0.0
0.3
0.8
0.4
0.6
0.5
-0.4
0.1
0.8
-0.1
0.4
-0.4
-0.8
-0.5
0.0
-0.8
-0.3
-1.1
-0.6
-0.9
-0.3
-0.6
-0.4
-0.5
-0.7
-0.6
0.7
0.0
0.4
0.0
-0.8
-0.4
-0.8
-0.6
-0.7
0.3
-0.2
0.1

Index (95=1)
2025
2050
1.4
1.7
1.2
1.2
1.3
1.4
1.1
1.0
1.3
1.2
0.9
0.7
1.0
0.8
0.7
0.6
0.9
0.8
0.9
0.7
1.2
1.3
1.0
0.8
0.8
0.7
1.1
1.1

Withdrawals (billion m )
1995
2025
2050
167
255
371
553
755
933
257
389
543
200
302
377
1,142
1,674
2,128
63
75
73
381
535
568
540
607
626
121
144
150
275
308
311
2,319
3,375
4,352
444
610
641
936
1,059
1,088
3,699
5,044
6,081

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Withdrawals (billion m )
1995
2025
2050
167
227
276
553
647
650
257
331
364
200
228
206
1,142
1,442
1,414
63
56
47
381
386
315
540
391
335
121
110
95
275
235
199
2,319
2,876
2,909
444
442
361
936
736
628
3,699
4,054
3,899

A-24

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet P-2. Water Withdrawals by Sector
100%

Agricultural

sector share

80%

Industrial
Domestic

60%
40%
20%
0%
1995

2025
2050
Reference

2025
2050
Policy Reform

Reference
SectorAgricultural
Industrial
Domestic
Total

3

Growth Rate (%/year)
95-25
25-50
95-50
0.9
0.5
0.7
1.3
1.1
1.2
1.5
1.2
1.3
1.0
0.8
0.9

Sectoral Share (%)
1995
2025
2050
69
65
62
20
22
23
11
13
15
100
100
100

3

Growth Rate (%/year)
95-25
25-50
95-50
0.3
0.0
0.1
-0.4
-1.3
-0.8
1.2
0.4
0.8
0.3
-0.2
0.1

Sectoral Share (%)
1995
2025
2050
69
69
71
20
16
12
11
15
17
100
100
100

Withdrawals (billion m )
1995
2025
2050
2,538
3,301
3,782
738
1,090
1,417
423
653
882
3,699
5,044
6,081

Policy Reform
SectorAgricultural
Industrial
Domestic
Total

Withdrawals (billion m )
1995
2025
2050
2,538
2,788
2,756
738
659
475
423
607
667
3,699
4,054
3,899

Bending the Curve: Toward Global Sustainability

A-25

Sheet P-3: Water Stress
Water Stress
5,000

AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

millions of people

4,000
3,000

2,000
1,000

0
1995

2025

2050

Reference

2025

2050

Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Use/Resource Ratio
Water Stress (millions of people) Water Stress (% of population)
1995
2025
2050
1995
2025
2050
1995
2025
2050
0.03
0.05
0.07
155
309
442
22
21
22
0.16
0.21
0.26
338
751
1,083
25
46
64
0.02
0.03
0.04
74
167
223
16
24
28
0.56
0.84
1.05
164
353
496
92
97
99
0.10
0.15
0.19
816
1,764
2,119
49
71
72
0.09
0.11
0.10
17
25
23
17
26
25
0.08
0.11
0.12
9
15
3
5
0.10
0.11
0.12
88
137
151
30
37
39
0.10
0.12
0.12
29
41
41
19
27
28
0.12
0.13
0.13
182
223
207
39
45
44
0.07
0.10
0.13
1,549
3,346
4,366
35
50
55
0.08
0.11
0.11
17
34
38
4
9
10
0.10
0.12
0.12
298
400
399
33
39
40
0.08
0.10
0.13
1,863
3,780
4,803
33
47
51

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Use/Resource Ratio
Water Stress (millions of people) Water Stress (% of population)
1995
2025
2050
1995
2025
2050
1995
2025
2050
0.03
0.04
0.05
155
285
393
22
20
20
0.16
0.18
0.18
338
562
545
25
35
34
0.02
0.02
0.03
74
122
116
16
18
15
0.56
0.64
0.57
164
336
450
92
94
95
0.10
0.13
0.13
816
1,526
1,750
49
63
63
0.09
0.08
0.07
17
11
6
17
12
7
0.08
0.08
0.06
0.10
0.07
0.06
88
50
28
30
14
7
0.10
0.09
0.08
29
21
11
19
14
8
0.12
0.10
0.08
182
139
88
39
28
19
0.07
0.08
0.09
1,549
2,833
3,256
35
44
43
0.08
0.08
0.06
17
11
6
4
3
2
0.10
0.08
0.07
298
210
127
33
21
13
0.08
0.08
0.08
1,863
3,055
3,391
33
39
38

A-26

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet P-4. Carbon Emissions
Reference

Policy Reform

16

AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

Gt C

12

8

4

0
1995

2025

2050

1995

2025

2050

2075

2100

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Total Annual Emissions (Gt C)
1995
2025
2050
0.17
0.65
1.39
0.87
2.00
2.60
0.30
0.75
1.15
0.25
0.64
0.93
0.57
1.75
3.22
0.19
0.23
0.20
0.75
0.94
0.96
1.49
2.22
2.40
0.39
0.44
0.44
0.95
1.16
1.24
2.16
5.79
9.29
0.94
1.17
1.16
2.83
3.82
4.08
5.94
10.78
14.53

Index (95=1)
Annual Per Capita (t C)
2025
2050
1995
2025
2050
3.9
8.3
0.2
0.4
0.7
2.3
3.0
0.7
1.2
1.5
2.5
3.8
0.6
1.1
1.4
2.5
3.7
1.4
1.8
1.9
3.1
5.6
0.3
0.7
1.1
1.2
1.1
1.9
2.3
2.2
1.3
1.3
2.6
3.2
3.3
1.5
1.6
5.0
6.0
6.2
1.1
1.1
2.6
2.8
3.0
1.2
1.3
2.0
2.4
2.6
2.7
4.3
0.5
0.9
1.2
1.2
1.2
2.4
3.0
3.0
1.3
1.4
3.1
3.8
4.1
1.8
2.4
1.0
1.3
1.6

Annual Per Dollar GDPPPP (kg C)
1995
2025
2050
0.14
0.16
0.15
0.23
0.17
0.12
0.10
0.10
0.08
0.27
0.20
0.14
0.13
0.12
0.10
0.32
0.22
0.15
0.62
0.43
0.32
0.19
0.12
0.09
0.12
0.07
0.05
0.13
0.08
0.06
0.16
0.14
0.11
0.52
0.36
0.26
0.15
0.10
0.07
0.18
0.13
0.10

Index (95=1)
Annual Per Capita (t C)
2025
2050
1995
2025
2050
5.3
7.2
0.2
0.6
0.6
2.2
1.7
0.7
1.2
0.9
2.0
2.0
0.6
0.9
0.8
2.4
2.2
1.4
1.7
1.1
3.1
3.2
0.3
0.7
0.7
0.8
0.5
1.9
1.6
1.1
0.9
0.5
2.6
2.3
1.4
0.6
0.4
5.0
2.4
1.5
0.6
0.4
2.6
1.4
1.0
0.6
0.4
2.0
1.2
0.9
2.7
2.6
0.5
0.9
0.7
0.9
0.5
2.4
2.2
1.3
0.6
0.4
3.1
1.7
1.1
1.4
1.2
1.0
1.1
0.8

Annual Per Dollar GDPPPP (kg C)
1995
2025
2050
0.14
0.14
0.07
0.23
0.14
0.06
0.10
0.08
0.04
0.27
0.17
0.07
0.13
0.10
0.05
0.32
0.14
0.06
0.62
0.27
0.11
0.19
0.07
0.04
0.12
0.05
0.03
0.13
0.05
0.03
0.16
0.12
0.06
0.52
0.23
0.09
0.15
0.06
0.03
0.18
0.10
0.05

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Total Annual Emissions (Gt C)
1995
2025
2050
0.17
0.89
1.19
0.87
1.95
1.47
0.30
0.61
0.61
0.25
0.61
0.54
0.57
1.78
1.86
0.19
0.15
0.10
0.75
0.68
0.38
1.49
0.90
0.59
0.39
0.21
0.14
0.95
0.59
0.41
2.16
5.83
5.67
0.94
0.83
0.48
2.83
1.70
1.15
5.94
8.37
7.30

Bending the Curve: Toward Global Sustainability

A-27

Sheet P-5. Sulfur Emissions

million tonnes S

150

AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

100

50

0
1995

2025
2050
Reference

2025
2050
Policy ReformR e fe ren ce
R e g io n
A fric a
C h in a +L a tin A m e ric a
M id d le E a s t
S + S E A s ia
E . E u ro p e
FSU
N . A m e ric a
P a c ific O E C D
W . E u ro p e
D e v e lo p in g
T ra n s itio n a l
O ECD
W o rld

E m is s io n s (m illio n to n n e s S )
1995
2025
2050
3
9
15
13
25
32
3
7
11
2
5
7
7
18
34
2
2
2
10
10
9
12
11
12
5
4
4
9
8
7
29
65
99
13
12
11
26
23
23
68
100
133

G ro w th R a te (% /y e a r)
9 5 -2 5
2 5 -5 0
9 5 -5 0
3 .9
2 .2
3 .1
2 .1
0 .9
1 .6
2 .3
1 .9
2 .1
2 .6
1 .3
2 .0
3 .1
2 .5
2 .8
0 .2
0 .0
0 .1
-0 .1
-0 .4
-0 .2
-0 .3
0 .2
-0 .1
-0 .9
-0 .3
-0 .6
-0 .3
-0 .4
-0 .3
2 .7
1 .7
2 .2
-0 .1
-0 .3
-0 .2
-0 .4
-0 .1
-0 .3
1 .3
1 .1
1 .2

In d e x (9 5 = 1 )
2025
2050
3 .1
5 .4
1 .9
2 .4
2 .0
3 .2
2 .1
2 .9
2 .5
4 .6
1 .1
1 .0
1 .0
0 .9
0 .9
1 .0
0 .8
0 .7
0 .9
0 .8
2 .2
3 .4
1 .0
0 .9
0 .9
0 .9
1 .5
2 .0

G ro w th R a te (% /y e a r)
9 5 -2 5
2 5 -5 0
9 5 -5 0
2 .5
-0 .1
1 .3
1 .2
-1 .4
0 .0
1 .9
0 .0
1 .1
1 .0
-0 .2
0 .5
2 .4
-0 .6
1 .0
-2 .3
-2 .1
-2 .2
-2 .3
-3 .0
-2 .6
-2 .5
-2 .7
-2 .6
-2 .7
-2 .8
-2 .7
-2 .7
-2 .7
-2 .7
1 .7
-0 .7
0 .6
-2 .3
-2 .8
-2 .5
-2 .6
-2 .7
-2 .6
0 .0
-1 .2
-0 .6

In d e x (9 5 = 1 )
2025
2050
2 .1
2 .0
1 .4
1 .0
1 .8
1 .8
1 .4
1 .3
2 .0
1 .7
0 .5
0 .3
0 .5
0 .2
0 .5
0 .2
0 .4
0 .2
0 .4
0 .2
1 .7
1 .4
0 .5
0 .2
0 .5
0 .2
1 .0
0 .7

P o lic y R e fo rm
R e g io n
A fric a
C h in a +L a tin A m e ric a
M id d le E a s t
S + S E A s ia
E . E u ro p e
FSU
N . A m e ric a
P a c ific O E C D
W . E u ro p e
D e v e lo p in g
T ra n s itio n a l
O ECD
W o rld

E m is s io n s (m illio n to n n e s S )
1995
2025
2050
3
6
6
13
19
14
3
6
6
2
3
3
7
15
13
2
1
1
10
5
2
12
6
3
5
2
1
9
4
2
29
49
41
13
6
3
26
12
6
68
67
50

A-28

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet P-6. Land-Use by Land-Type
100%

Other

80%

PastureProtected

60%

Forest40%

Cropland
Built
Environment

20%
0%
1995

2025

2050

Reference

2025

2050

Policy Reform

Reference
Land Type
Built Environment
Cropland
ForestPastureProtected
Other
Total

Land area (million ha)
1995
2025
2050
268
440
613
1,450
1,534
1,606
4,022
3,650
3,334
3,395
3,674
3,862
825
825
825
3,042
2,880
2,762
13,002
13,002
13,002Growth Rate (%/year)
95-25
25-50
95-50
1.7
1.3
1.5
0.2
0.2
0.2
-0.3
-0.4
-0.3
0.3
0.2
0.2
0.0
0.0
0.0
-0.2
-0.2
-0.2
-

Index (95=1)
2025
2050
1.6
2.3
1.1
1.1
0.9
0.8
1.1
1.1
1.0
1.0
0.9
0.9
1.0
1.0

Land area (million ha)
1995
2025
2050
268
404
505
1,450
1,618
1,744
4,022
3,803
3,845
3,395
3,691
3,605
825
821
821
3,042
2,666
2,483
13,002
13,002
13,002Growth Rate (%/year)
95-25
25-50
95-50
1.38
0.89
1.16
0.37
0.30
0.34
-0.19
0.04
-0.08
0.28
-0.09
0.11
-0.02
0.00
-0.01
-0.44
-0.28
-0.37
-

Index (95=1)
2025
2050
1.5
1.9
1.1
1.2
0.9
1.0
1.1
1.1
1.0
1.0
0.9
0.8
1.0
1.0

Policy Reform
Land Type
Built Environment
Cropland
ForestPastureProtected
Other
Total

Bending the Curve: Toward Global Sustainability

A-29

Sheet P-7. Land-Use by Region
Reference Scenario
1995

2050

100%

Other
Protected
PastureForests
Cropland
Built Environment

80%
60%
40%

20%

W. Europe

Pacific OECD

N. America

FSU

E. Europe

S+SE Asia

Middle East

Latin America

China +

AfricaW. Europe

Pacific OECD

FSU

N. America

E. Europe

S+SE Asia

Middle East

Latin America

China +

Africa0%

1 99 5R e g io n
A fric a
C h in a +L a tin A m e ric a
M id d le E a s t
S + S E A s ia
E . E u ro p e
FSU
N . A m e ric a
P a c ific O E C D
W . E u ro p e
D e v e lo p in g
T ra n s itio n a l
O ECD
W o rld

B u ilt
2
3
1
2
6
4
1
2
1
6
2
1
2
2

C ro p la n d
6
9
7
7
34
44
10
13
7
27
10
12
13
11

L a n d a re a (% )F o re s ts
P a s tu re P ro te c te d
24
30
5
15
45
0
46
29
8
3
37
3
40
4
9
27
16
8
36
16
3
39
15
10
20
52
12
31
17
10
29
30
5
36
16
3
33
25
11
31
26
6

O th e r
33
27
9
47
6
1
34
21
9
10
24
32
16
23

Built
5
8
4
6
17
6
1
3
1
7
6
1
3
5

Cropland
9
9
9
8
36
42
10
13
8
28
12
12
14
12

Land area (% )Forests
Pasture Protected
14
41
5
9
48
0
40
32
8
0
38
3
26
7
9
25
16
8
35
17
3
39
14
10
16
56
12
30
16
10
20
35
5
35
17
3
32
25
11
26
30
6

Other
26
26
8
45
4
3
33
21
6
10
20
32
16
21

2050
RegionAfricaChina +
Latin Am erica
Middle East
S+SE Asia
E. Europe
FSU
N. Am erica
Pacific O ECD
W . Europe
Developing
TransitionalOECD
W orldT o ta l A re a(m illio n h a )2 ,9 6 4
1 ,1 5 8
2 ,0 1 8604
848
89
2 ,1 9 5
1 ,8 3 8829
461
7 ,5 9 1
2 ,2 8 4
3 ,1 2 7
1 3 ,0 0 2

A-30

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet P-7. Land-Use by Region (continued)
Policy Reform Scenario
1995

2050

100%

Other
Protected
PastureForests
Cropland
Built Environment

80%

60%

40%

20%

W. Europe

Pacific OECD

N. America

FSU

E. Europe

S+SE Asia

Middle East

Latin America

China +

AfricaW. Europe

Pacific OECD

FSU

N. America

E. Europe

S+SE Asia

Middle East

Latin America

China +

Africa0%

1995
R e g io n
A fric a
C h in a +L a tin A m e ric a
M id d le E a s t
S + S E A s ia
E . E u ro p e
FSU
N . A m e ric a
P a c ific O E C D
W . E u ro p e
D e v e lo p in g
T ra n s itio n a l
O ECD
W o rld

B u ilt
2
3
1
2
6
4
1
2
1
6
2
1
2
2

C ro p la n d
6
9
7
7
34
44
10
13
7
27
10
12
13
11

L a n d a re a (% )F o re s ts
P a s tu re P ro te c te d
24
30
5
15
45
0
46
29
8
3
37
3
40
4
9
27
16
8
36
16
3
39
15
10
20
52
12
31
17
10
29
30
5
36
16
3
33
25
11
31
26
6

O th e r
33
27
9
47
6
1
34
21
9
10
24
32
16
23

B u ilt
4
7
2
5
16
5
1
2
1
6
5
1
2
4

C ro p la n d
10
9
10
9
30
46
11
18
7
33
12
13
17
13

L a n d a re a (% )F o re s ts
P a s tu re P ro te c te d
21
37
5
15
44
0
45
29
8
3
35
3
37
6
9
26
14
8
36
16
3
39
14
10
19
56
12
30
16
10
27
32
5
35
16
3
32
25
11
30
28
6

O th e r
23
24
7
45
2
0
33
17
5
5
18
31
12
19

2050
R e g io n
A fric a
C h in a +L a tin A m e ric a
M id d le E a s t
S + S E A s ia
E . E u ro p e
FSU
N . A m e ric a
P a c ific O E C D
W . E u ro p e
D e v e lo p in g
T ra n s itio n a lOECD
W o rld

T o ta l A re a(m illio n h a )2 ,9 6 4
1 ,1 5 8
2 ,0 1 8604
848
89
2 ,1 9 5
1 ,8 3 8829
461
7 ,5 9 1
2 ,2 8 4
3 ,1 2 7
1 3 ,0 0 2

Bending the Curve: Toward Global Sustainability

A-31

Sheet P-8. Fertilizer Consumption
AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

250

million tonnes

200

150

100

50

0
1995

2025
2050
Reference

2025
2050
Policy ReformR e fer en c e
R e gion
A fricaC h ina +Latin A m eric a
M id dle E ast
S + S E A sia
E . E uro pe
FSU
N . A m e rica
P a cific O E C D
W . E uro pe
D e v elop ing
T ra nsitio nal
OECD
W o rld

C o nsum ption (m illion to nnes)
199 5
202 5
205 0
4
13
30
32
42
43
9
20
30
2
6
6
24
51
64
3
5
6
5
13
17
22
26
28
4
4
3
20
24
23
71
132
174
7
19
23
45
55
55
123
205
251

G rowth R ate (% /y ear)
95-25
25-50
95-50
4.4
3.5
4.0
1.0
0.1
0.6
2.6
1.6
2.1
2.9
0.4
1.8
2.6
0.9
1.8
2.2
0.7
1.5
3.7
0.9
2.4
0.7
0.3
0.5
0.3
-1.1
-0.3
0.7
-0.3
0.3
2.1
1.1
1.6
3.2
0.9
2.1
0.7
0.0
0.3
1.7
0.8
1.3

Ind ex (9 5= 1)
202 5
205 0
3.7
8.6
1.3
1.4
2.1
3.2
2.4
2.6
2.1
2.7
1.9
2.3
3.0
3.7
1.2
1.3
1.1
0.8
1.2
1.2
1.9
2.5
2.6
3.2
1.2
1.2
1.7
2.0

G rowth Rate (% /year)
95-25
25-50
95-50
3.8
1.7
2.9
0.0
-1.5
-0.7
1.6
0.5
1.1
1.9
-1.2
0.5
1.6
-1.0
0.4
1.5
-0.9
0.4
2.8
-0.3
1.4
0.0
-0.6
-0.3
-0.6
-2.8
-1.6
-0.1
-1.5
-0.7
1.1
-0.5
0.4
2.4
-0.5
1.1
-0.1
-1.1
-0.5
0.8
-0.7
0.2

Index (95= 1)
2025
2050
3.1
4.7
1.0
0.7
1.6
1.8
1.7
1.3
1.6
1.2
1.6
1.3
2.3
2.1
1.0
0.9
0.8
0.4
1.0
0.7
1.4
1.2
2.0
1.8
1.0
0.7
1.3
1.1

P olicy R eform
R egionA fricaC hina +Latin A m erica
M iddle East
S +S E A sia
E . E urope
F SU
N . A m erica
P acific O E C D
W . E urope
D ev eloping
T ransitional
O EC DW orldC onsum ption (m illion tonnes)
1995
2025
2050
4
11
17
32
31
21
9
15
17
2
4
3
24
38
30
3
4
3
5
10
10
22
21
19
4
3
2
20
19
13
71
100
88
7
15
13
45
44
34
123
158
134

A-32

Raskin, Gallopin, Gutman, Hammond and Swart

Sheet P-9. Fisheries
200

Aquaculture
Conventional
Fisheries

million tonnes

150

100

Maximum
Sustainable
Conventional
Fisheries Catch

50

0
1995

2025
2050
Reference

2025
2050
Policy Reform

ReferenceType
Conventional Fisheries
Aquaculture
Total

Production (million tonnes)
1995
2025
2050
88
88
88
20
63
82
108
151
170

Growth Rate (%/year)
95-25
25-50
95-50
0.0
0.0
0.0
3.9
1.0
2.6
1.1
0.5
0.8

Index (95=1)
2025
2050
1.0
1.0
3.2
4.1
1.4
1.6

Production (million tonnes)
1995
2025
2050
88
93
93
20
56
70
108
149
163

Growth Rate (%/year)
95-25
25-50
95-50
0.2
0.0
0.1
3.5
0.9
2.3
1.1
0.4
0.7

Index (95=1)
2025
2050
1.1
1.1
2.8
3.5
1.4
1.5

Policy Reform
Type
Conventional Fisheries
Aquaculture
Total

Bending the Curve: Toward Global Sustainability

A-33

Sheet P-10. Toxic Waste
70

AfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe

million tonnes

60
50
40
30
20
10
0
1995

2025

2050

Reference

2025

2050

Policy Reform

Reference
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

Toxic Waste (million tonnes)
1995
2025
2050
0.7
2.3
5.3
3.8
8.8
13.6
1.9
4.4
7.3
0.8
2.2
3.9
3.0
8.6
17.2
0.4
0.6
0.8
1.2
1.7
2.0
3.9
6.4
7.9
2.2
3.0
3.4
3.8
5.3
6.1
10
26
47
2
2
3
10
15
17
22
43
68

Growth Rate (%/year)
95-25
25-50
95-50
4.0
3.3
3.7
2.9
1.7
2.4
2.7
2.1
2.4
3.5
2.3
2.9
3.6
2.8
3.3
1.6
0.8
1.2
1.1
0.7
0.9
1.6
0.9
1.3
1.0
0.6
0.8
1.1
0.6
0.9
3.2
2.4
2.8
1.2
0.8
1.0
1.3
0.7
1.0
2.3
1.8
2.1

Index (95=1)
2025
2050
3.2
7.3
2.3
3.6
2.3
3.8
2.8
4.9
2.9
5.8
1.6
2.0
1.4
1.7
1.6
2.0
1.4
1.6
1.4
1.6
2.6
4.6
1.4
1.7
1.5
1.8
2.0
3.1

Toxic Waste (million tonnes)
1995
2025
2050
0.7
1.4
0.6
3.8
3.6
1.0
1.9
1.8
0.5
0.8
0.9
0.3
3.0
3.8
1.4
0.4
0.2
0.1
1.2
0.7
0.2
3.9
2.0
0.4
2.2
1.1
0.2
3.8
1.9
0.4
10
11
4
2
1
0
10
5
1
22
17
5

Growth Rate (%/year)
95-25
25-50
95-50
2.1
-3.0
-0.2
-0.2
-4.9
-2.4
-0.4
-4.6
-2.3
0.3
-4.3
-1.8
0.8
-3.9
-1.4
-1.5
-5.7
-3.4
-1.9
-5.7
-3.6
-2.3
-6.2
-4.1
-2.3
-6.2
-4.1
-2.3
-6.2
-4.1
0.4
-4.2
-1.7
-1.8
-5.7
-3.6
-2.3
-6.2
-4.1
-0.8
-4.8
-2.6

Index (95=1)
2025
2050
1.9
0.9
0.9
0.3
0.9
0.3
1.1
0.4
1.3
0.5
0.6
0.1
0.6
0.1
0.5
0.1
0.5
0.1
0.5
0.1
1.1
0.4
0.6
0.1
0.5
0.1
0.8
0.2

Policy Reform
RegionAfricaChina +
Latin America
Middle East
S+SE Asia
E. Europe
FSU
N. America
Pacific OECD
W. Europe
Developing
Transitional
OECD
World

A-34

Raskin, Gallopin, Gutman, Hammond and SwartBending the Curve: Toward Global Sustainability

A-35

Abbreviations
GDP
MER
PPP
GDPPPPGDPMEROECD
PCL

gross domestic productmarket exchange rate
purchasing power parity
GDP in international dollars adjusted for PPP
GDP in US dollars at MER
Organization for Economic Cooperation and Development
potential cultivable land

o

cal
g
ha
m
mpg
t
tC
J

degree centigrade
calories
gram
hectaremeter
miles per gallon
tonne
tonne of carbon
Joules

E
P
T
G
M
k

Exa, 1018
Peta, 1015
Tera, 1012
Giga, 109
Mega, 106kilo, 103

Selected Conversion Factors
Energy
1 GJ
Volume
1 km3
Mass
1 tonneArea
1 ha
Fuel Efficiency
1 mpg (US)=0.172 BOE=

0.0239 TOE=

264.2⋅109 US gallons=

810.7⋅103 acre⋅foot=1000 kg=

1.10 short ton=

2.47 acre=

0.0100 km2=

0.425 km/liter=

0.0341 TCE=

2.20⋅103 pounds

A-36

Raskin, Gallopin, Gutman, Hammond and SwartBending the Curve: Toward Global Sustainability

A-37

Data Notes
All Sheets: Scenario assumptions are summarized in text and described in detail in Heaps, et al. (1998).
Sheet D-1: Base year and Reference population from mid-range UN (1997). For Policy Reform
population, see Section 4.2.
Sheet D-2: Values for 1995 and 2025 computed using data from WRI (1994; 1996). Changes from 2025
to 2050 assume a slowing urbanization trend relative to 1995-2025.
Sheet E-1: GDPPPP and GDPMER computed using GDPPPP per capita from CIA (1997), GDPMER per capita
from World Bank (1997) and populations from mid-range UN (1997).
Sheet E-2: Value added by sector from World Bank (1997). Estimates based on market exchange rates,
using the most recent available data from 1992-1995. Percentages based on countries where data
available.
Sheet E-3: Regional values are population-weighted averages of country GDPPPP per capita from CIA(1997). Scenario growth rates based on GDPMER growth rates (IPCC, 1992a), adapted for the regions inthis study and converted to PPP growth rates (Heaps, et al., 1998).
Sheet S-1: All values weighted by national populations. Based on Gini coefficients from Deininger andSquire (1996), U.S. Census (1997), Tabatabai (1996) and World Bank (1998), with additional estimates(Heaps, et al., 1998). Distributional equity is the ratio of the average income of the lowest earning 20% to
the highest earning 20% of the population, estimated assuming lognormal national income distributions.
Sheet S-2: For most developing countries, data are based on FAO estimates of the incidence of chronic
undernutrition (FAO, 1997a); for the US, the incidence of food insecurity was used (Rose et al., 1995); forall other countries estimates are based on income distribution (Heaps, et al., 1998).
Sheets En-1…4: Data from IEA energy statistics (IEA, 1997a,b). In sheets En-3 and En-4, final energy
demand is defined as consumption of electricity and fuels by end-users. In sheets En-1 and En-2, primaryenergy in each region is the sum of final energy demand in the region, energy lost through thetransformation of primary to secondary fuel forms, and net energy lost or used during transmission anddistribution. Care should be taken in interpreting primary energy supply figures since different statisticalsources use different conventions for reporting the primary energy content of nuclear and renewablesources of energy. The conventions for efficiency adopted in this study are: uranium at 33%, geothermal
at 10%, and hydro, wind, solar and other renewables at 100%. Other sources may express hydro resourcesin terms of an equivalent fossil fuel feedstock requirement.
Sheet En-5: Data from WEC Survey of Energy Resources (WEC, 1995). See definition of proven andundiscovered reserves in Section 3.3.2. Uranium estimates assume conventional fission reactors.
Estimates do not include non-conventional oil and natural gas resources.
Sheet F-1: Base year values from FAO (1996b). Daily consumption is the amount available for
consumption.
Sheets F-2…4: Base year values from FAO (1996b).
Self-sufficiency ratio calculated as
production/requirements. Net exports in the base year include net additions to stocks. Meat includes
eggs; milk includes all products derived from milk. Fraction from feedlots is the fraction of total
production in caloric terms. Fish includes all seafood.
Sheet F-5: Base year values from FAO (1996b). Annual yield defined as total annual production per unit
area of cropland. Harvest yield is production per unit area per harvest. Cropping intensity is a measure ofmultiple cropping, given by:cropping intensity = annual yield harvest yield .
The index shown is for Annual yield.
Sheets F-6, 7: Base year values from FAO (1996b). Cropland includes land for growing sugarcane forenergy and food.

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Raskin, Gallopin, Gutman, Hammond and Swart

Sheets F-8: Existing cropland from FAO (1996b). Potential cropland for developing regions based ondata from Fischer (1993). For OECD and transitional regions, see Heaps, et al. (1998). Potential
cultivable land includes active farmland and other land-types potentially suitable for farming. It is lost
through land degradation and conversion to other land uses.
Sheets P-1, 2: Data are for total freshwater withdrawals from Najlis (1996) and Shiklomanov (1997),
supplemented by Raskin et al. (1995).
Sheet P-3: Use/Resource ratio is total freshwater requirements divided by renewable freshwater resources,
including river flows from adjacent countries. Base year data from Najlis (1996) and Shiklomanov(1997), supplemented by Raskin et al. (1995). Water stress is discussed in Sections 2.2, 3.3 and 4.6.
Sheet P-4: Emissions are estimated from energy consumption data and emissions factors based on IPCC
(1995b). 1 GtC = 1 billion tonnes carbon. Emissions are from combustion of fossil fuel only; theyexclude net emissions from land-use changes and from non-energy industrial processes, which contributed
an additional 1.5 GtC in 1995 (IPCC, 1996).
Sheet P-5: Data based on Posch et al. (1996) and Kuylenstierna (1998) with additional assumptions.
Includes energy sector SOx emissions and industrial process SOx emissions.
Sheets P-6, 7: Areas currently under cropland, forest and pasture from FAO (1996b); areas under built
environment for developing regions from Fischer (1993); other regions estimated from various sources(see Heaps, et al., 1998); protected areas Fischer (1993) and WCMC (1998a,b); area of “Other Land”
computed as balance using total land area from FAO (1996b).
Sheet P-8: Consumption of manufactured fertilizer (FAO, 1996b).
Sheet P-9: Total production from FAO (1996b); aquaculture production and maximum sustainablefisheries catch from FAO (1997). Maximum sustainable catch is higher in the Policy Reform scenario.
Better management of capture fisheries is assumed to extend the current production of around 85 million
tonnes per year to a sustained annual production of 100 million tonnes (FAO, 1997c).
Sheet P-10: Data based on World Bank Industrial Pollution Projection System (Hettige et al., 1994).