ULYSSES and Integrated Assessment

It is frequently argued that Integrated Assessment (IA) should be an international, multi-institute program, in which projects are covering for each other. In the current chapter, the research described in the first two parts of this volume is discussed from such a broad point of view. To that end, the authors explore if, and if so how, this research built upon previous IA projects and whether it provided input for subsequent IA projects. In doing so, its value for Integrated Assessment beyond the study's main products and insights is explored.

Apart from being a project that addressed the climatic change issue from the perspective of citizens, the ULYSSES project was explicitly designed as an Integrated Assessment (IA) project. For decades, scientists have been working with decision-makers to address local and regional problems in a more or less integrative manner, especially in the field of environmental policy, most of them without calling it “Integrated Assessment.” Although the term IA dates back to the 1980s, it is only since the late 1990s that IA has been recognized as a kind of profession and as a specific branch of scientific research. For that reason, it was not at all trivial that the project explicitly aimed to develop new IA methodologies.

When this study was designed, modelers, mainly natural scientists and economists, dominated IA. Modeling was considered as the way to do IA.

The controversy at the core of this chapter is whether current and anticipated trends in economic and social development, combined with projections for population growth, are compatible with maintaining good health for all. Whereas there has been a doubling of life expectancy over the past century, there are still considerable uncertainties about how the health transition will continue. The way in which such trends are interpreted depends to a large extent on the perspectives held by scientists and policy-makers. In this chapter, developments in population that are related to policy and health dynamics are interpreted according to the three perspectives outlined in Chapter 10 and are compared to UN projections. The consequences for population size and the health risks of stagnating economic growth and of food and water crises are assessed in four cases.

Controversies related to population and health

World population has more than tripled between 1900 and 1996, rising from about 1.6×109 (Kuznets, 1966) to 5.8×109 (UNFPA, 1996), i.e. an average annual growth of 1.3%. Such a rate of growth is extremely rapid by any historical perspective. Population growth and its potential consequences for people and the environment have long been an issue of concern. Since the time of Malthus (1789) the population issue has been the subject of a furious debate, both in the scientific and the policy community (Ehrlich, 1968; Cohen, 1995). Specific concerns about population growth have varied from one generation to the next.

The central question in this chapter is: can the world population be provided with an adequate and sustainable supply of clean water? We report on experiments with the AQUA submodel and attempt to offer insight into the role of population and economic growth, intensive agriculture, technology and pricing. Again three cultural perspectives are applied to establish model routes which reflect different assumptions and societal responses. The model experiments provide a number of water projections for the next century. We review low, medium and high risk developments and the effects of various water policy strategies. The chapter concludes with a proposal for future policy priorities to safeguard a sustainable supply of clean fresh water.

Introduction

There are too many uncertainties to give a simple answer to the question whether we will have enough clean water for the next century. However, we can do some exploratory work if we make certain assumptions. In this chapter, we present such an exploration based on the AQUA submodel (Chapter 6). As a heuristic device for composing coherent sets of assumptions, different perspectives are used (see Chapter 10). First, we discuss some of the major questions, uncertainties and controversies related to water and sustainable development. We then look for coherence in the different points of view by considering the controversies from three perspectives: the hierarchist, the egalitarian and the individualist. Next, we use the three perspectives to implement ‘model routes’ within the AQUA submodel and to present model–based projections of water in the next century. Finally, we distinguish low, moderate and high risk futures, and analyse the effects of different water policy strategies. More detailed background information can be found in Hoekstra (1997).

Introduction

We know that the future is inherently uncertain, yet we are fascinated by insights into ways in which we may be influencing the planet. This interest is intensified because there is widespread perception that the world is changing at an unprecedented speed. Undeniably, many parts of the global system are accelerating or decelerating compared to previously observed, natural rates of change. For some people these processes of change may just look like more of the same. There are, however, underlying behavioural and structural changes at work which suggest deeper, more radical change in the longer term. Many of those long-term changes can be viewed as part of transition processes. Several of these are within the human system: from many to 1 or 2 children per family, twice as many older people per thousand compared to today, a factor of 3 to 5 less energy and water use per unit of economic activity, increasing pressure to cultivate more land and use it more intensively to feed the population. More gradual, but possibly of overriding importance, are the changes in the environmental system, such as the accelerating increase in the concentration of some atmospheric gases and increasing accumulation of pollutants in soils and water bodies which are the result of past and present practices. It is difficult to disentangle the human-induced, structural long-term changes from the natural changes, which makes it even harder to see where the world is heading.

The key question underlying the controversies addressed in this chapter is to what extent the global biogeochemical cycles and the climate system are being disturbed by anthropogenic processes. The CYCLES submodel is used to explore the influence of various model routes on future projections of global environmental change. These routes are characterised by specific assumptions about the key processes within the global carbon (C) and nitrogen (N) cycle and the climate system. This creates the possibility to assess various emission scenarios, paving the way for the more integrated experiments described in Chapters 17 and 18. It is reiterated that the current state of scientific knowledge with respect to global C and N cycles and climate change is still beset with major uncertainties.

Introduction

Although scientific knowledge of global biogeochemical cycles is increasing rapidly, there are still major gaps. Subjective interpretation of these gaps results in different assessments of the rate, magnitude and impacts of human-induced changes in global cycles. The climate debate exemplifies the kind of intellectual battle that can take place, given uncertainties about the global biogeochemical cycles of the basic elements carbon (C), nitrogen (N), phosphorus (P) and sulphur (S), and the climate system. In general, the controversies within the scientific community on global biogeochemical cycles focus on the relationships among the physical, biological and chemical processes comprising the complex dynamics of the global biogeochemical cycling as well as the role of the various feedbacks.

This chapter introduces Part Two of the book, which reports on experiments with submodels of TARGETS 1.0 carried out to assess a number of global change controversies. The experiments include a range of utopias and dystopias to discover whether the problem at the core of each controversy is likely to occur, and if so, under what conditions. The hierarchist utopia, which reflects the assumptions behind many reputable scenario studies, is used as a reference case to explore issues such as population growth, demand for food, water and energy, the environmental consequences of these pressures, and a range of societal responses. The results of integrated experiments with the TARGETS 1.0 model are presented at the end of this part of the book.

Introduction

Part One of this book described tools for performing integrated assessments of global change. The aim of Part Two is to gain insights by using these tools, both withthe separate submodels and with the integrated TARGETS 1.0 model. The main goal of TARGETS is to put possible developments within the subsystems of the world into perspective in an integrated way. In this way we hope to provide a context for discussing global change and sustainable development. The quantitative modelling framework is used to support the qualitative framing of important issues. Though they are partial and limited in scope, the resulting images of possible global futures enable us to localise areas of tension and directions for sustainable development strategies.

In this chapter we use the TERRA submodel to explore whether malnutrition and food insecurity can be eliminated while safeguarding the productive potential and broader environmental functions of agricultural resources for future generations. This is done within the context of the three cultural perspectives. The food problem is explained not so much as a problem of production but as one of availability and distribution. The submodel simulations are, however, largely confined to aggregate food demand and supply. Costs and environmental trade-offs are assessed in both utopian and dystopian worlds to determine under what conditions the planet will be able to feed its future population. We explore perspective-based scenarios for population and GWP, the surface area available for cropping, the use of irrigation, fertilisers and other inputs, wood production, reforestation, and the effects of changes in atmospheric CO2 and temperature.

Introduction

Currently, sufficient food is produced to feed the world population, yet at the same time more than 1,000 million people cannot afford or do not have the possibility to buy enoughfood to live healthy and productive lives. More than 500 million are chronically undernourished (FAO, 1993a). Malnutrition and food insecurity are not so much related to food production but rather to the unequal distribution of available food (IFPRI, 1995). This is caused by socio-economic factors such as poverty, the political situation, deficient infrastructure and (food) trade.

Any exploration of future developments inevitably involves a considerable degree of uncertainty and integrated assessment modelling is no exception. One of the major uncertainties has to do with the direction of policy-making. In order to accommodate a wide variety of world views and management styles, this chapter introduces the concept of multiple model routes. These are alternative ways of looking at model relationships, taking into account the bias and preferences of a number of stereo-typical perspectives. These perspectives, which each represent a different attitude to nature and society, are typified as hierarchist, egalitarian, individualist and fatalist. Matching a consistent management style with the first three (active) perspectives permits an analysis of ‘utopias’, while the opposite case – when world view and management style are out of step – reveals the risk of a number of possible ‘dystopias’.

Introduction

The future is inherently uncertain and thus unpredictable. Nevertheless, people in general, and decision-makers in particular, are interested in exploring future developments in order to make plans. One of the roles of science is to assist decisionmakers by sketching images of the future of the planet and of humankind. Scientists are facing an increase in both the magnitude and the degree of complexity. The issues currently associated with global change differ from other scientific problems in several respects (Funtowicz and Ravetz, 1993):

• they are global in scale and long term in their impact;

• the available data is lamentably inadequate; and

• the phenomena, being novel, complex and variable, are themselves not well understood.

This chapter provides an introduction to the theme of the book by explaining the importance of the three central concepts global change, sustainable development and integrated assessment. The book focuses on five areas: population and human health, energy, water, land and food, and global biogeochemical cycles. The idea of using multiple definitions of sustainable development in an integrated approach to global change is put forward. The construction and use of the TARGETS integrated assessment model (Tool to Assess Regional and Global Environmental and health Targets for Sustainability) is justified in terms of providing a platform for communication within the scientific community that can inform policy debates about likely trends over the next 100 years or so.

Introduction

With the approach of a new millennium, global change and sustainable development are evolving as key concepts for assessing the future of the planet and of humankind. Over the last few decades, we have become used to the idea that our activities may have serious and irreversible impacts on the environment. Human-induced changes are recognised as having the potential to significantly modify the structure and functioning of the Earth system as a whole. Furthermore, activities at one place on Earth can affect the lives of people around the globe and even jeopardise those of future generations. The use of land, water, minerals and other natural resources by humans has increased more than tenfold during the past two centuries.

When tackling a subject as complex as global change and sustainable development, it is essential to be able to ‘frame the issues’. This was one of the main reasons for developing the TARGETS model, an integrated model of the global system, consisting of metamodels of important subsystems. In this chapter we introduce TARGETS. Building on the previous chapters, we elaborate on the possibilities and limitations of integrated assessment models. Some of the key issues discussed are aggregation, model calibration and validation, and dealing with uncertainty.

Introduction

One of the main tools used in integrated assessment of global change issues is the Integrated Assessment (IA) model. This chapter introduces such an integrated model, TARGETS, which builds upon the systems approach and related concepts introduced in Chapter 2. Previous integrated modelling attempts either focused on specific aspects of global change, for instance the climate system (IPCC, 1995), or consisted merely of conceptual descriptions (Shaw et al., 1992). We have tried to go one step further, linking a series of cause-effect chains of global change. Although we realise the shortcomings in our current version of the TARGETS model, we felt there was a need to present our model to a wide audience. We first give some advantages and limitations of IA models. Next, we discuss issues of aggregation, calibration, validation and uncertainty. We proceed with a brief description of the five TARGETS submodels which coincides with the PSIR concept and the vertical integration as introduced in Chapter 2. A more detailed description of these submodels is given in Chapters 4 to 8.

Global change is an extremely complex phenomenon, encompassing a wide variety of issues. An adequate approach to such a broad subject demands careful consideration of a host of interactions between people and the environment and a clear understanding of driving forces, be the demographic, social, economic or technological. If we wish to tackle such a complex issue, we need to establish some basic guiding concepts. This chapter proposes an integrated systems approach to a number of key aspects of global change: population, health, energy, land, water and element cycles. We define what we mean by ‘system’ and ‘model’ and introduce a conceptual framework for analysing global change. As a mechanism to structure this conceptual framework we use the Pressure-State-Impact-Response (PSIR) approach. We look at two different kinds of integration (vertical and horizontal) and discuss different levels of complexity. Finally, we explain the importance of communicating the results of integrated systems analysis and suggest the value of using different communication methods such as indicators and visualisation.

Introduction

Most systematic studies of global change have so far focused on subsystems in isolation. However, it is well known that when parts are combined into more complex structures, the resulting system may exhibit quite different properties and behaviour (Gregory, 1981). As mentioned in Chapter 1, there is a growing interest in an integrated approach to global change (for an overview see Parson (1996) and Rotmans et al. (1996)).