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.

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.

Introduction

One of the major foci of linguistic research during the last decade has been the development of a theory of binding. Despite a reasonable amount of consensus on major issues, there are a number of persistent anomalies. Especially, an integrated view of so-called long-distance anaphors is lacking. The present book sets out to contribute to the development of such a view. In the individual chapters a number of important issues in the theory of local and long-distance anaphors are analysed. The purpose of this overview is to summarize and interpret the results. In section 2 we provide the necessary background. Section 3 summarizes the individual contributions and puts them into context. Section 4 presents an overview of the facts reported. Section 5 discusses a major result of the book as a whole: the existence of just two main classes of A-anaphors.

Binding theory and its parameters

The starting point of most current discussions of anaphora is the binding theory (BT) developed by Chomsky in a series of works from 1973 on. (1) gives the formulation in Chomsky (1981).

1. A. An anaphor is bound in its governing category.

2. B. A pronominal is free in its governing category.

3. C. An R-expression is free.

The definition of ‘governing category’ is given in (2).

(2) b is a governing category for a if and only if b is the minimal category containing a, a governor of a, and a SUBJECT (accessible to a).

This volume is a collection of original articles on the nature of the anaphoric systems in a variety of languages and from a number of different perspectives. The aim of the editors is to provide a new impetus to the study of long-distance anaphors, a phenomenon with ramifications that are rather puzzling from the perspective of the binding theory in its canonical form (as in Chomsky (1981)). All of the contributions are concerned with extending that theory in a manner that is as restrictive as possible. Some of the solutions solidly remain within the domain of the structural binding theory. In other cases, developing a restrictive theory required recognizing different components in binding, and assigning a specific role to pragmatic factors. Many of the articles converge, however, in important respects, leading to considerable simplification of the overall picture. The patterns found in the languages covered are so consistent that they cannot be accidental (although one would certainly wish to investigate a larger number of languages).

Most of the articles originated as contributions to a workshop on long-distance anaphora organized by the Department of Linguistics of Groningen University, 18–20 June 1987. The editors added a first chapter in which the main results of the volume are put together. The original plans were for this chapter to be written by the editors together with Tanya Reinhart, who participated in the workshop as a discussant.