Introduction

This framing chapter has two primary purposes: to provide a frame-work for viewing and understanding the human (social) perspective on climate change, focusing on ethics and economics; and to define and discuss key concepts used in other chapters. It complements the two other framing chapters: Chapter 2 on risk and uncertainty and Chapter 4 on sustainability. The audience for this chapter (indeed for this entire volume) is decision makers at many different levels.

The significance of the social dimension and the role of ethics and economics is underscored by Article 2 of the United Nations Framework Convention on Climate Change (UNFCCC), which indicates that the ultimate objective of the Convention is to avoid dangerous anthropogenic interference with the climate system. Two main issues confronting society are: what constitutes ‘dangerous interference’ with the climate system and how to deal with that interference (see box 3.1). Providing information to answer these inter-related questions is a primary purpose of the IPCC. Although natural science helps us understand how emissions can change the climate, and, in turn, generate physical impacts on ecosystems, people, and the physical environment, determining what is dangerous involves judging the level of adverse consequences, the steps necessary to mitigate these consequences, and the risk that humanity is willing to tolerate. These are questions requiring value judgement. Although economics is essential to evaluating the consequences and trade-offs associating with climate change, how society interprets and values them is an ethical question.

Our discussion of ethics centres on two main considerations: justice and value. Justice requires that people and nations should receive what they are due, or have a right to. For some, an outcome is just if the process that generated it is just. Others view justice in terms of the actual outcomes enjoyed by different people and groups and the values they place on those outcomes.