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7 - The land and food submodel: TERRA
- from Part One - The TARGETS model
- Edited by Jan Rotmans, National Institute of Public Health and Environment (RIVM), The Netherlands, Bert de Vries, National Institute of Public Health and Environment (RIVM), The Netherlands
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- Book:
- Perspectives on Global Change
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- 06 July 2010
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- 16 October 1997, pp 135-158
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Summary
The aim of the land and food submodel is to simulate the key features of the global changes in land use and land cover that result from demand for food and the requirements of forestry. The submodel can reproduce the major historical trends in land use and land cover, food demand and supply, fertiliser use, etc. This is done, to a large extent, by employing of exogenous policy scenarios. The interaction with the other submodels, in particular CYCLES, allows the exploration of linkages between population growth, water availability and climate change on the one hand and food production on the other.
Introduction
The Earth's vegetation patterns have always changed in response to natural changes in, for example, geology, biology and climate. However, over the last few centuries human activities have made a considerable contribution to such changes. Natural ecosystems, forests, savannahs and wetlands have all been severely affected. The combination of growing populations and higher per capita food consumption has led to the gradual expansion of the land area used for food production and grazing. Increasing population density has led to forms of permanent agriculture which make more intensive use of land and this trend towards intensification is likely to continue in the decades to come. The growing demand for food may cause an imbalance between what can be produced and what is needed.
18 - Uncertainty and risk: dystopian futures
- from Part Two - Exploring images of the future
- Edited by Jan Rotmans, National Institute of Public Health and Environment (RIVM), The Netherlands, Bert de Vries, National Institute of Public Health and Environment (RIVM), The Netherlands
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- Book:
- Perspectives on Global Change
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- 06 July 2010
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- 16 October 1997, pp 395-416
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Summary
This chapter explores dystopian futures. After a summary of the uncertainties and risks discussed for each of the subsystems, integrated experiments are presented in which world view and management style throughout the world system are at odds. We also investigate the effectiveness of various response options and of the timing of certain policy measures.
Introduction
In the previous chapter we outlined possible futures which are based on coherent sets of assumptions about how the world system functions and how it is managed. These are called utopias and constitute the diagonal elements in the matrix presented in Figure 10.7. In a way, they are idealised and therefore implausible images of the future. In this chapter we first present some simulation experiments in which dystopian trends are explored with the integrated TARGETS 1.0 model. This is a prelude to the next section in which we analyse in more detail images of the future where world view and management style are at odds. These are referred to as integrated dystopias (see Chapter 11) and they are actually more plausible because they contain real-world tensions between diverging world views and management styles. Two major chains which cause feedback loops are presented as a framework discussing some interesting dystopian futures and to give an assessment of associated risks. Finally, we explore the adequacy of response actions in terms of intensity and timing, and the consequences of allocating insufficient investments to the food, water and energy sectors.
8 - The biogeochemical submodel: CYCLES
- from Part One - The TARGETS model
- Edited by Jan Rotmans, National Institute of Public Health and Environment (RIVM), The Netherlands, Bert de Vries, National Institute of Public Health and Environment (RIVM), The Netherlands
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- Book:
- Perspectives on Global Change
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- 06 July 2010
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- 16 October 1997, pp 159-186
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Summary
The CYCLES submodel describes the long-term dynamics of the global biogeochemical cycles of carbon (C), nitrogen (N), phosphorus (P) and sulphur (S), their interactions and their impacts on climate change. The model analysis balances past carbon and nitrogen budgets – emphasising the importance of the N fertilisation feedback – and supports the future projections of the fate of anthropogenic emissions of both carbon and nitrogen compounds in the global environment presented in Chapter 16. This chapter focuses on the link between the global cycles of C and N and their feedbacks, providing calculations of global flows of these basic elements and their related compounds within and between the major reservoirs.
Introduction
Carbon, hydrogen and oxygen, together with the basic nutrient elements nitrogen, phosphorus and sulphur, are essential for life on Earth. The term ‘global biogeochemical cycles’ is used to describe the transport and transformation of these substances in the global environment. In recent decades detailed studies have been carried out on the global biogeochemical cycles of the basic elements, in particular carbon (C), nitrogen (N), phosphorus (P) and sulphur (S) (Bolin et al., 1979; Bolin and Cook, 1983; Schlesinger, 1991; Butcher et al., 1992; Wollast et al., 1993). Figure 8.1 depicts how anthropogenic disturbances of the global cycles of the basic elements of C, N, P and S lead to a variety of global environmental consequences.
19 - Global change: fresh insights, no simple answers
- from Part Two - Exploring images of the future
- Edited by Jan Rotmans, National Institute of Public Health and Environment (RIVM), The Netherlands, Bert de Vries, National Institute of Public Health and Environment (RIVM), The Netherlands
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- Book:
- Perspectives on Global Change
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- 06 July 2010
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- 16 October 1997, pp 417-434
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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.
16 - Human disturbance of the global biogeochemical cycles
- from Part Two - Exploring images of the future
- Edited by Jan Rotmans, National Institute of Public Health and Environment (RIVM), The Netherlands, Bert de Vries, National Institute of Public Health and Environment (RIVM), The Netherlands
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- Book:
- Perspectives on Global Change
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- 06 July 2010
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- 16 October 1997, pp 345-370
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Summary
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.
11 - Towards integrated assessment of global change
- from Part Two - Exploring images of the future
- Edited by Jan Rotmans, National Institute of Public Health and Environment (RIVM), The Netherlands, Bert de Vries, National Institute of Public Health and Environment (RIVM), The Netherlands
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- Book:
- Perspectives on Global Change
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- 06 July 2010
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- 16 October 1997, pp 223-238
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Summary
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.
15 - Food for the future
- from Part Two - Exploring images of the future
- Edited by Jan Rotmans, National Institute of Public Health and Environment (RIVM), The Netherlands, Bert de Vries, National Institute of Public Health and Environment (RIVM), The Netherlands
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- Book:
- Perspectives on Global Change
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- 06 July 2010
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- 16 October 1997, pp 319-344
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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.
3 - The TARGETS model
- from Part One - The TARGETS model
- Edited by Jan Rotmans, National Institute of Public Health and Environment (RIVM), The Netherlands, Bert de Vries, National Institute of Public Health and Environment (RIVM), The Netherlands
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- Book:
- Perspectives on Global Change
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- 06 July 2010
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- 16 October 1997, pp 33-54
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Summary
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.
17 - The larger picture: utopian futures
- from Part Two - Exploring images of the future
- Edited by Jan Rotmans, National Institute of Public Health and Environment (RIVM), The Netherlands, Bert de Vries, National Institute of Public Health and Environment (RIVM), The Netherlands
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- Book:
- Perspectives on Global Change
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- 06 July 2010
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- 16 October 1997, pp 371-394
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Summary
This chapter synthesises the insights gained from the model experiments made in the previous five chapters. The hierarchist utopia examined in Chapter 11 is only one possible future. We now explore the consequences of two other utopian futures: the egalitarian and the individualist. A selection of conditional forecasts from integrated simulation experiments with population, food, water and energy supplies, land use, global temperature and sea-level rise are presented. One way of looking at the model outcomes is by focusing on the various transitions which characterise the development of the human-environment system. Extending the time horizon of the model simulations into the 22nd century yields additional insights into the relation between the human and the environmental system.
Introduction
The main goal of the TARGETS 1.0 model is to place possible developments within the subsystems of the world in an integrated perspective. In Chapters 12 to 16, simulation results of experiments with the TARGETS 1.0 submodels are discussed in isolation, while in Chapter 11 the results of an integrated simulation experiment for the hierarchist utopia are presented. In this chapter, we pursue this analysis further and include the other two perspectives. In this way we elaborate on the various controversies which have been raised in the preceding chapters: can a large population be maintained at an adequate health level and will there be enough energy, water and food without overburdening the natural environment? We start with the integrated utopias which are based on assumptions about world view and management style taken from a single perspective for all submodels (see Table 11.1).