Over the last two decades, scientists have radically improved their understanding of the causes and consequence of global warming-the warming of the Earth as a consequence of greenhouse gases (GHGs) building up in the atmosphere? The Intergovernmental Panel on Climate Change (IPCC), created by governments in 1988 to study climate change, has concluded with 'very high confidence that the global average net effect of human activities since 1750 has been one of warming' (IPCC 2007/ 37). Carbon dioxide, the most influential GHG in aggregate, is emitted through the burning of fossil fuels (for example, coal, oil, natural gas), and when trees are felled and subsequently decay or are burned. 'Climate change' refers to

changes in climate and their consequences resulting from global warming, with the United Nations (UN) Framework Convention on Climate Change (FCCC) including under this rubric atmospheric changes connected directly or indirectly to human activities.3 This human-induced global warming waSt until recently, viewed as a future problem. But it is becoming clearer that ongoing climatic changes are consequences of global warming ('Climate change' 2006). The impacts of climate change on natural ecosystems and on human society and economies are potentially severe, particularly in parts of the world where geographic vulnerability and poverty make adaptation difficult or impossible. Furthermore, what is important in understanding the politics of climate change is that it is intimately connected to most economic activity and modern lifestyles, thereby tying Earth systems intimately with human systems (see Figure 1).