ABSTRACT
This chapter lays the foundation for an exploration of the bigger issues by clearly identifying the ways in which climate change is harmful. It provides a brief discussion of climate change and its possible effects. The chapter explores the ways in which the complexity of the climate system can challenge our understanding of how climate change is harmful. It addresses the ways in which the intergenerational nature of climate change dominates our ability to understand the ways in which climate change is harmful and proposes a way of understanding what we mean when we say climate change is harmful. Understanding the physical processes of climate change requires understanding the relationship between atmospheric greenhouse gas (GHG) concentrations and mean global surface temperatures as well as the relationship between GHG emissions and atmospheric GHG concentrations. Current atmospheric GHG concentrations "have increased to levels unprecedented in at least the last 800,000 years", having risen by 40" since pre-industrial times.
